Trial Outcomes & Findings for Azithromycin-Prevention in Labor Use Study (A-PLUS) (NCT NCT03871491)

NCT ID: NCT03871491

Last Updated: 2024-10-24

Results Overview

Maternal death or sepsis within 6 weeks (42 days) post-delivery in intervention vs. placebo group.

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 58747 participants
• Primary outcome timeframe: Within 6 weeks (42 days)
• Results posted on: 2024-10-24

Participant Flow

Randomized, multi-country, double-masked, placebo-controlled trial of azithromycin (single 2g oral dose) initiated during labor, in women who were in labor at 28 weeks' gestation or more and who were planning a vaginal delivery

Participants were randomly assigned (1:1, stratified by site) to receive azithromycin or placebo tablets of identical appearance, via a sequence generated centrally by the data coordinating center. Mother were randomized and the maternal participant and her baby or babies in the case of multiple pregnancies were enrolled.

Participant milestones

Measure	Azithromycin Intervention (Mothers) The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin.	Azithromycin Intervention (Neonates) The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.	Placebo (Mothers) By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery.	Placebo (Neonates) By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.
Overall Study STARTED	14590	14687	14688	14782
Overall Study Treated	14589	14686	14687	14781
Overall Study Included in Intention to Treat (ITT) Analysis	14590	14687	14688	14782
Overall Study COMPLETED	14526	14658	14637	14756
Overall Study NOT COMPLETED	64	29	51	26

Reasons for withdrawal

Measure	Azithromycin Intervention (Mothers) The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin.	Azithromycin Intervention (Neonates) The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.	Placebo (Mothers) By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery.	Placebo (Neonates) By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.
Overall Study Withdrawal by Subject	14	14	14	14
Overall Study Physician Decision	0	0	1	1
Overall Study Lost to Follow-up	50	15	36	11

Baseline Characteristics

This measure applies to mothers randomized and does not apply to neonates/stillbirths.

Baseline characteristics by cohort

Measure	Azithromycin Intervention (Mothers) n=14590 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin.	Azithromycin Intervention (Neonates) n=14687 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.	Placebo (Mothers) n=14688 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery.	Placebo (Neonates) n=14782 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.	Total n=58747 Participants Total of all reporting groups
Age, Continuous	24 years n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	24 years n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	24 years n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Sex/Gender, Customized Female	14590 Participants n=14590 Participants	7123 Participants n=14687 Participants	14688 Participants n=14688 Participants	7190 Participants n=14782 Participants	43591 Participants n=58747 Participants
Sex/Gender, Customized Male	0 Participants n=14590 Participants	7563 Participants n=14687 Participants	0 Participants n=14688 Participants	7591 Participants n=14782 Participants	15154 Participants n=58747 Participants
Sex/Gender, Customized Missing Sex	0 Participants n=14590 Participants	1 Participants n=14687 Participants	0 Participants n=14688 Participants	1 Participants n=14782 Participants	2 Participants n=58747 Participants
Race and Ethnicity Not Collected	—	—	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment Bangladesh	1406 Participants n=14590 Participants	1408 Participants n=14687 Participants	1441 Participants n=14688 Participants	1446 Participants n=14782 Participants	5701 Participants n=58747 Participants
Region of Enrollment Pakistan	1825 Participants n=14590 Participants	1841 Participants n=14687 Participants	1843 Participants n=14688 Participants	1862 Participants n=14782 Participants	7371 Participants n=58747 Participants
Region of Enrollment Congo, The Democratic Republic of the	2181 Participants n=14590 Participants	2220 Participants n=14687 Participants	2192 Participants n=14688 Participants	2231 Participants n=14782 Participants	8824 Participants n=58747 Participants
Region of Enrollment Guatemala	794 Participants n=14590 Participants	794 Participants n=14687 Participants	803 Participants n=14688 Participants	803 Participants n=14782 Participants	3194 Participants n=58747 Participants
Region of Enrollment Zambia	1769 Participants n=14590 Participants	1784 Participants n=14687 Participants	1765 Participants n=14688 Participants	1779 Participants n=14782 Participants	7097 Participants n=58747 Participants
Region of Enrollment Kenya	1829 Participants n=14590 Participants	1835 Participants n=14687 Participants	1844 Participants n=14688 Participants	1846 Participants n=14782 Participants	7354 Participants n=58747 Participants
Region of Enrollment India	4786 Participants n=14590 Participants	4805 Participants n=14687 Participants	4800 Participants n=14688 Participants	4815 Participants n=14782 Participants	19206 Participants n=58747 Participants
Marital status Married	13729 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	13834 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	27563 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Marital status Single	612 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	600 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1212 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Marital status Other	248 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	253 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	501 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Marital status Missing	1 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	2 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Maternal education No formal schooling	3457 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	3476 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	6933 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Maternal education 1-6 years of schooling	2002 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	2022 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	4024 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Maternal education 7-12 years of schooling	7308 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	7325 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	14633 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Maternal education >= 13 years of schooling	1798 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1842 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	3640 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Maternal education Missing	25 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	23 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	48 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Primiparous Yes	6311 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	6376 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	12687 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Primiparous No	8277 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	8311 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	16588 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Primiparous Missing	2 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	3 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Multiple birth Yes	99 Participants n=14590 Participants	198 Participants n=14687 Participants	95 Participants n=14688 Participants	190 Participants n=14782 Participants	582 Participants n=58747 Participants
Multiple birth No	14489 Participants n=14590 Participants	14489 Participants n=14687 Participants	14592 Participants n=14688 Participants	14592 Participants n=14782 Participants	58162 Participants n=58747 Participants
Multiple birth Missing	2 Participants n=14590 Participants	0 Participants n=14687 Participants	1 Participants n=14688 Participants	0 Participants n=14782 Participants	3 Participants n=58747 Participants
Any maternal infection during pregnancy Yes	797 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	821 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1618 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Any maternal infection during pregnancy No	13792 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	13866 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	27658 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Any maternal infection during pregnancy Missing	1 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	2 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Any maternal condition during pregnancy Yes	1017 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	955 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1972 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Any maternal condition during pregnancy No	13572 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	13732 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	27304 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Any maternal condition during pregnancy Missing	1 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	2 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Gestational age < 37 weeks Yes	1841 Participants n=14590 Participants	1889 Participants n=14687 Participants	1895 Participants n=14688 Participants	1944 Participants n=14782 Participants	7569 Participants n=58747 Participants
Gestational age < 37 weeks No	12742 Participants n=14590 Participants	12791 Participants n=14687 Participants	12789 Participants n=14688 Participants	12834 Participants n=14782 Participants	51156 Participants n=58747 Participants
Gestational age < 37 weeks Missing	7 Participants n=14590 Participants	7 Participants n=14687 Participants	4 Participants n=14688 Participants	4 Participants n=14782 Participants	22 Participants n=58747 Participants
Type of labor onset Induced	2651 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	2724 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	5375 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Type of labor onset Spontaneous	11930 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	11953 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	23883 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Type of labor onset Missing	9 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	11 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	20 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
High risk for sepsis before randomization Yes	1247 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1283 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	2530 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
High risk for sepsis before randomization No	13341 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	13404 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	26745 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
High risk for sepsis before randomization Missing	2 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	3 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Prolonged labor >= 18 hours before randomization Yes	670 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	698 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1368 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Prolonged labor >= 18 hours before randomization No	13918 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	13989 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	27907 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Prolonged labor >= 18 hours before randomization Missing	2 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	3 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Prolonged rupture of membranes >= 8 hours before randomization Yes	615 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	632 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1247 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Prolonged rupture of membranes >= 8 hours before randomization No	13973 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	14055 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	28028 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.
Prolonged rupture of membranes >= 8 hours before randomization Missing	2 Participants n=14590 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	1 Participants n=14688 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.	—	3 Participants n=29278 Participants • This measure applies to mothers randomized and does not apply to neonates/stillbirths.

PRIMARY outcome

Timeframe: Within 6 weeks (42 days)

Population: Intention to treat (ITT)

Maternal death or sepsis within 6 weeks (42 days) post-delivery in intervention vs. placebo group.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal Death or Sepsis Within 6 Weeks (42 Days) Post-delivery in Intervention vs. Placebo Group.	227 Participants	344 Participants

PRIMARY outcome

Timeframe: Within 4 weeks (28 days) post-delivery

Population: Intention to treat (ITT)

Intrapartum/neonatal death or sepsis within 4 weeks (28 days) post-delivery in intervention vs. placebo group. This outcome is measured among stillbirths and neonates with 28-day status available born to women randomized. The study includes multiple births so there are more stillbirths and neonates than participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Intrapartum/Neonatal Death or Sepsis Within 4 Weeks (28 Days) Post-delivery in Intervention vs. Placebo Group	1,540 Participants	1,526 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Maternal sepsis required a diagnosis of sepsis according to the study algorithm or no diagnosis and follow-up data on/beyond 7 days.

Maternal sepsis within 6 weeks (42 days) post-delivery in intervention vs. placebo group.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal Sepsis	219 Participants	339 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Maternal death due to sepsis required maternal status at 42-days to be included in the denominator.

Maternal death due to sepsis using the Global Network algorithm for cause of death

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal Death Due to Sepsis	4 Participants	1 Participants

SECONDARY outcome

Timeframe: Between date/time of randomization and date/time of delivery (up to 120 hours before delivery)

Population: Intention to treat (ITT)

Fever (>100.4°F/38°C) in addition to one or more of the following: fetal tachycardia ≥160 bpm, maternal tachycardia >100 bpm, tender uterus between contractions, or purulent/foul smelling discharge from uterus prior to delivery.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Chorioamnionitis	5 Participants	8 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Endometritis required a diagnosis according to the study algorithm or no diagnosis and follow-up data on/beyond 7 days.

Fever (>100.4°F/38°C) in addition to one or more of maternal tachycardia >100 bpm, tender uterine fundus, or purulent/foul smelling discharge from uterus after delivery.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Endometritis	191 Participants	294 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery

Population: Intention to treat (ITT). This outcome variable is analyzed for the subgroup of women with a cesarean delivery. Numbers differ from the participant flow ITT population due to this subgroup analysis and missing data specific to this secondary outcome. Cesarean wound infection required a diagnosis according to the study algorithm or no diagnosis and follow-up data on/beyond 7 days.

Wound infection (Purulent infection of a Cesarean wound with or without fever. In the absence of purulence, requires presence of fever >100.4°F/38°C and at least one of the following signs of local infection: pain or tenderness, swelling, heat, or redness around the incision/laceration);

Outcome measures

Measure	Intervention n=2 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=2 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Cesarean Wound Infection	77 Participants	134 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery

Population: Intention to treat (ITT). This outcome variable analyzed for the subgroup of women with a vaginal delivery. Numbers differ from the participant flow ITT population due to this subgroup analysis and missing data specific to this secondary outcome. Perineal wound infection required a diagnosis according to the study algorithm or no diagnosis and follow-up data on/beyond 7 days.

Wound infection (Purulent infection of a perineal wound with or without fever. In the absence of purulence, requires presence of fever >100.4°F/38°C and at least one of the following signs of local infection: pain or tenderness, swelling, heat, or redness around the incision/laceration);

Outcome measures

Measure	Intervention n=12 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=12 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Perineal Wound Infection	149 Participants	188 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Other infections required a diagnosis according to the study algorithm or no diagnosis and follow-up data on/beyond 7 days.

Abdominopelvic abscess (Evidence of pus in the abdomen or pelvis noted during open surgery, interventional aspiration or imaging); Pneumonia (Fever >100.4°F/38°C and clinical symptoms suggestive of lung infection including cough and/or tachypnea >24 breaths/min or radiological confirmation); Pyelonephritis (Fever >100.4°F/38°C and one or more of the following: urinalysis/dip suggestive of infection, costovertebral angle tenderness, or confirmatory urine culture); Mastitis/breast abscess or infection (Fever >100.4°F/38°C and one or more of the following: breast pain, swelling, warmth, redness, or purulent drainage). Other bacterial infection.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Other Infections	149 Participants	217 Participants

SECONDARY outcome

Timeframe: After randomization to 42 days post-delivery. Randomization occurs between labor onset and delivery (0 to 120 hours before delivery). 42 participants were randomized >120 hours before delivery due to false labor.

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Use of subsequent maternal antibiotic therapy required a yes response or a no response on follow-up data on/beyond 7 days.

Use of subsequent maternal antibiotic therapy after randomization to 42 days postpartum for any reason.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Use of Subsequent Maternal Antibiotic Therapy	7,937 Participants	8,180 Participants

SECONDARY outcome

Timeframe: Time from drug administration (which occurs between onset of labor and delivery) and discharge from delivery hospital (0 to 45 days)

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Time from drug administration until initial discharge after delivery required non-missing date and time variables for discharge after delivery.

Time from drug administration until initial discharge after delivery (time may vary by site).

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal Initial Hospital Length of Stay	1.4 days Standard Deviation 1.8	1.4 days Standard Deviation 1.9

SECONDARY outcome

Timeframe: After delivery discharge and within 42 days post-delivery

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Maternal readmissions required non-missing date of delivery discharge and a readmission or no indication of a readmission and follow-up data on/beyond 7 days.

Maternal readmissions after delivery discharge and within 42 days of delivery

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal Readmissions	124 Participants	192 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery (reported during study)

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Maternal admission to special care units required a yes response or a no response on follow-up data on/beyond 7 days.

Maternal admission to special care units

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal Admission to Special Care Units	116 Participants	130 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery (reported during study)

Population: Intention to treat (ITT). Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Maternal unscheduled visit for care required a visit for unscheduled care or a no visit reported on follow-up data on/beyond 7 days.

Maternal unscheduled visit for care

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal Unscheduled Visit for Care	1,397 Participants	1,790 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery (reported during study)

Population: Safety population. This is the Treated row of the participant flow.

Maternal GI symptoms including nausea, vomiting, and diarrhea and other reported side effects.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Maternal GI Symptoms	119 Participants	110 Participants

SECONDARY outcome

Timeframe: Within 28 days post-delivery

Population: Intention to treat (ITT) for live births. Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Neonatal sepsis is defined among live births so excludes stillbirths. Neonatal sepsis required a diagnosis of sepsis according to the study algorithm or no diagnosis and follow-up data on/beyond 7 days.

Neonatal sepsis within 4 weeks (28 days) post-delivery in intervention vs. placebo group. This outcome is measured among neonates born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Neonatal Sepsis	1,433 Participants	1,407 Participants

SECONDARY outcome

Timeframe: Within 28 days post-delivery

Population: Intention to treat (ITT) for live births. Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Neonatal death due to sepsis is defined among live births so excludes stillbirths. Neonatal death due to sepsis required status at 28 days.

Neonatal death due to sepsis using the Global Network algorithm for causes of death. This outcome is measured among neonates with 28-day status available born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Neonatal Death Due to Sepsis	64 Participants	62 Participants

SECONDARY outcome

Timeframe: Within 28 days post-delivery

Population: Intention to treat (ITT) for live births. Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Other neonatal infections is defined among live births so excludes stillbirths. Other neonatal infections required a diagnosis according to the study algorithm or no diagnosis and follow-up data on/beyond 7 days.

Other neonatal infections (e.g. eye infection, skin infection). This outcome is measured among neonates born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Other Neonatal Infections	763 Participants	798 Participants

SECONDARY outcome

Timeframe: Time from delivery to discharge from delivery hospital (0 to 62 days)

Population: Intention to treat (ITT) for live births. Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Neonatal initial hospital length of stay is defined among live births so excludes stillbirths. Neonatal initial hospital length of stay required non-missing date and time of hospital discharge.

Neonatal initial hospital length of stay, defined as time of delivery until initial discharge (time may vary by site). This outcome is measured among neonates born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Neonatal Initial Hospital Length of Stay	1.5 days Standard Deviation 2.4	1.5 days Standard Deviation 2.1

SECONDARY outcome

Timeframe: After delivery discharge and within 42 days of delivery

Population: Intention to treat (ITT)

Neonatal readmissions to facility after delivery discharge and within 42 days of delivery. This outcome is measured among neonates born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Neonatal Readmissions	553 Participants	518 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery (reported during study)

Population: Intention to treat (ITT) for live births. Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Neonatal admission to special care units is defined among live births so excludes stillbirths. Neonatal admission to special care units required a yes response or a no response on follow-up data on/beyond 7 days.

Neonatal admission to special care units. This outcome is measured among neonates born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Neonatal Admission to Special Care Units	951 Participants	927 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery (reported during study)

Population: Intention to treat (ITT) for live births. Numbers differ from the participant flow ITT population due to missing data specific to this secondary outcome. Neonatal unscheduled visit for care is defined among live births so excludes stillbirths. Neonatal unscheduled visit for care required a reported unplanned care visit or no unplanned care reported on follow-up data on/beyond 7 days.

Neonatal unscheduled visit for care. This outcome is measured among neonates born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Neonatal Unscheduled Visit for Care	3,223 Participants	3,366 Participants

SECONDARY outcome

Timeframe: Within 42 days post-delivery

Population: Safety population for live births. Numbers differ from Treated in the participant flow because they are live births among treated mothers.

Pyloric stenosis within 42 days of delivery, defined as clinical suspicion based on severe vomiting leading to death, surgical intervention (pyloromyotomy) as verified from medical records, or radiological confirmation. This outcome is measured among neonates born to women randomized. The study includes multiple births so there are more neonates than maternal participants enrolled.

Outcome measures

Measure	Intervention n=14 Participants The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered as four 500 mg pills or tablets directly after randomization. By random allocation, participants will receive 2 g of oral azithromycin.	Placebo n=14 Participants By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered as a single oral dose directly after randomization.
Pyloric Stenosis Within 42 Days of Delivery	8 Participants	3 Participants

Adverse Events

Azithromycin Intervention (Mothers)

Serious events: 3 serious events

Other events: 1022 other events

Deaths: 12 deaths

Azithromycin Intervention (Neonates)

Serious events: 11 serious events

Other events: 8 other events

Deaths: 291 deaths

Placebo (Mothers)

Serious events: 3 serious events

Other events: 1110 other events

Deaths: 11 deaths

Placebo (Neonates)

Serious events: 8 serious events

Other events: 3 other events

Deaths: 286 deaths

Serious adverse events

Measure	Azithromycin Intervention (Mothers) n=14589 participants at risk The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin.	Azithromycin Intervention (Neonates) n=14686 participants at risk The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.	Placebo (Mothers) n=14687 participants at risk By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery.	Placebo (Neonates) n=14781 participants at risk By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.
Pregnancy, puerperium and perinatal conditions Maternal death	0.02% 3/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.01% 1/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Pregnancy, puerperium and perinatal conditions Other maternal serious adverse event	0.00% 0/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.01% 2/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Pregnancy, puerperium and perinatal conditions Stillbirth	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.01% 1/14686 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.01% 1/14781 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Pregnancy, puerperium and perinatal conditions Neonatal death	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.06% 9/14627 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.03% 5/14725 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Pregnancy, puerperium and perinatal conditions Other neonatal serious adverse event	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.01% 1/14627 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.01% 2/14725 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).

Other adverse events

Measure	Azithromycin Intervention (Mothers) n=14589 participants at risk The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin.	Azithromycin Intervention (Neonates) n=14686 participants at risk The study intervention is a single 2 g dose of directly observed oral azithromycin. Azithromycin: The study intervention is a single 2 g dose of directly observed oral azithromycin, to be administered to maternal participants as four 500 mg pills or tablets directly after randomization which occurs between the onset of labor and delivery. By random allocation, participants will receive 2 g of oral azithromycin. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.	Placebo (Mothers) n=14687 participants at risk By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery.	Placebo (Neonates) n=14781 participants at risk By random allocation, participants will receive four oral placebo pills containing a non-antimicrobial agent directly after randomization. Placebo: Identical appearing placebo, administered to maternal participants as a single oral dose directly after randomization, which occurs between the onset of labor and delivery. Stillbirths and live births of maternal participants randomized are considered enrolled to the arm which their mother was randomized.
General disorders Severe abdominal or uterine pain	1.2% 170/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	1.4% 208/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Gastrointestinal disorders Vomited within 15 minutes after study drug administration	2.1% 311/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	1.9% 279/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Cardiac disorders Feeling faint or dizzy	1.7% 241/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	2.1% 309/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Gastrointestinal disorders Nausea/vomiting	0.31% 45/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.33% 48/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Gastrointestinal disorders Diarrhea/loose stools	0.52% 76/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.45% 66/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
General disorders Foul-smelling vaginal discharge	0.25% 37/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.57% 83/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
General disorders Severe vaginal pain	2.1% 309/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	2.2% 329/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Gastrointestinal disorders GI symptoms and other reported side effects	0.82% 119/14589 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.75% 110/14687 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).
Gastrointestinal disorders Pyloric stenosis	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.05% 8/14627 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	— 0/0 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).	0.02% 3/14726 • Adverse events were monitored continuously throughout the study from time of randomization (between onset of labor and delivery) through 6-weeks post delivery. Surveillance of maternal side effects potentially associated with azithromycin was conducted during labor and postpartum. For infants, findings suggestive of pyloric stenosis were assessed during the follow up visits. Maternal and neonatal surveillance included assessment of unintended medical visits and death. Potential side effects with azithromycin use were monitored and reported as a serious adverse event. Adverse events are reported among the Safety population (Treated).

Additional Information

Elizabeth McClure

RTI International

Phone: 919-316-3773

Email: mcclure@rti.org

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place