Trial Outcomes & Findings for Understanding COVID-19 Infection in Pregnant Women and Their Babies (NCT NCT04703270)
NCT ID: NCT04703270
Last Updated: 2025-06-18
Results Overview
Antibody concentrations in maternal blood in pregnant women in England: ADCD-S values reported
Recruitment status
COMPLETED
Target enrollment
881 participants
Primary outcome timeframe
Delivery
Results posted on
2025-06-18
Participant Flow
Participants had their antibodies against SARS-CoV-2 tested prior to assignment of a group.
Participant milestones
| Measure |
Exposed
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation regardless of antibody status.
|
Unexposed
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation.
|
Vaccinated
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who received a vaccine against SARS-CoV-2 prior to delivery.
|
Vaccinated and Exposed
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who also received a vaccine against SARS-CoV-2 prior to delivery.
|
|---|---|---|---|---|
|
Overall Study
STARTED
|
173
|
627
|
43
|
38
|
|
Overall Study
COMPLETED
|
173
|
627
|
43
|
38
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Understanding COVID-19 Infection in Pregnant Women and Their Babies
Baseline characteristics by cohort
| Measure |
Exposed
n=173 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation regardless of antibody status.
|
Unexposed
n=627 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation.
|
Vaccinated
n=43 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who received a vaccine against SARS-CoV-2 prior to delivery.
|
Vaccinated and Exposed
n=38 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who also received a vaccine against SARS-CoV-2 prior to delivery.
|
Total
n=881 Participants
Total of all reporting groups
|
|---|---|---|---|---|---|
|
Age, Continuous
|
33.0 years
n=5 Participants
|
31.0 years
n=7 Participants
|
34.0 years
n=5 Participants
|
33.5 years
n=4 Participants
|
32.0 years
n=21 Participants
|
|
Sex: Female, Male
Female
|
173 Participants
n=5 Participants
|
627 Participants
n=7 Participants
|
43 Participants
n=5 Participants
|
38 Participants
n=4 Participants
|
881 Participants
n=21 Participants
|
|
Sex: Female, Male
Male
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=21 Participants
|
|
Race/Ethnicity, Customized
White
|
85 Participants
n=5 Participants
|
496 Participants
n=7 Participants
|
32 Participants
n=5 Participants
|
24 Participants
n=4 Participants
|
637 Participants
n=21 Participants
|
|
Race/Ethnicity, Customized
Asian/Asian British
|
9 Participants
n=5 Participants
|
54 Participants
n=7 Participants
|
8 Participants
n=5 Participants
|
4 Participants
n=4 Participants
|
75 Participants
n=21 Participants
|
|
Race/Ethnicity, Customized
Black African/Caribbean/British
|
4 Participants
n=5 Participants
|
20 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
24 Participants
n=21 Participants
|
|
Race/Ethnicity, Customized
Other
|
8 Participants
n=5 Participants
|
12 Participants
n=7 Participants
|
2 Participants
n=5 Participants
|
1 Participants
n=4 Participants
|
23 Participants
n=21 Participants
|
|
Race/Ethnicity, Customized
Mixed/Multiple
|
1 Participants
n=5 Participants
|
12 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
13 Participants
n=21 Participants
|
|
Race/Ethnicity, Customized
Not Stated
|
66 Participants
n=5 Participants
|
33 Participants
n=7 Participants
|
1 Participants
n=5 Participants
|
9 Participants
n=4 Participants
|
109 Participants
n=21 Participants
|
PRIMARY outcome
Timeframe: DeliveryAntibody concentrations in maternal blood in pregnant women in England: ADCD-S values reported
Outcome measures
| Measure |
Exposed
n=173 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation regardless of antibody status.
|
Unexposed
n=627 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation.
|
Vaccinated
n=43 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who received a vaccine against SARS-CoV-2 prior to delivery.
|
Vaccinated and Exposed
n=38 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who also received a vaccine against SARS-CoV-2 prior to delivery.
|
|---|---|---|---|---|
|
Antibody Concentrations in Maternal Blood in Pregnant Women in England
|
37.2 CAU/ml
Interval 13.2 to 102.1
|
7.2 CAU/ml
Interval 5.0 to 5.0
|
80.3 CAU/ml
Interval 31.9 to 228.3
|
590.5 CAU/ml
Interval 308.7 to 1094.8
|
PRIMARY outcome
Timeframe: DeliveryPopulation: Number of participants analysed represents all those for whom a sample was received that was sufficient for analysis with the assay.
Cord blood was tested to determine infant antibody levels; where a cord blood sample was not available, a blood sample was taken from the infant instead. ADCD-S assay results are presented.
Outcome measures
| Measure |
Exposed
n=139 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation regardless of antibody status.
|
Unexposed
n=489 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation.
|
Vaccinated
n=32 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who received a vaccine against SARS-CoV-2 prior to delivery.
|
Vaccinated and Exposed
n=27 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who also received a vaccine against SARS-CoV-2 prior to delivery.
|
|---|---|---|---|---|
|
Antibody Concentrations in Cord/Infant Blood at Delivery
|
35.9 CAU/mL
Interval 11.7 to 88.4
|
7.5 CAU/mL
Interval 5.0 to 5.0
|
83.9 CAU/mL
Interval 29.8 to 227.8
|
549.0 CAU/mL
Interval 323.9 to 1314.7
|
SECONDARY outcome
Timeframe: At birthPopulation: Most participants did not provide a breastmilk sample of sufficient quantity for analysis.
Number of participants with breastmilk samples positive for antibodies specific to SARS-CoV-2
Outcome measures
| Measure |
Exposed
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation regardless of antibody status.
|
Unexposed
n=1 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation.
|
Vaccinated
n=29 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who received a vaccine against SARS-CoV-2 prior to delivery.
|
Vaccinated and Exposed
n=1 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who also received a vaccine against SARS-CoV-2 prior to delivery.
|
|---|---|---|---|---|
|
Number of Participants With Breastmilk Samples Positive for Antibodies Specific to SARS-CoV-2
|
—
|
0 Participants
|
16 Participants
|
0 Participants
|
SECONDARY outcome
Timeframe: DeliveryPopulation: No sufficient samples were received to enable rtPCR testing of mother and baby within a pair after sample testing for the primary outcome.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: DeliveryPopulation: All pairs for which a neonatal sample was received for the delivery timepoint were analysed. No delivery secretion samples were taken from neonates in the Unexposed group as per the study protocol.
Outcome measures
| Measure |
Exposed
n=116 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation regardless of antibody status.
|
Unexposed
n=2 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation.
|
Vaccinated
n=18 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who received a vaccine against SARS-CoV-2 prior to delivery.
|
Vaccinated and Exposed
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who also received a vaccine against SARS-CoV-2 prior to delivery.
|
|---|---|---|---|---|
|
Number of Mother-infant Pairs Who Are Both rtPCR Positive for SARS-CoV-2 in Secretions at Delivery
|
0 Number of mother-infant pairs
|
0 Number of mother-infant pairs
|
0 Number of mother-infant pairs
|
—
|
SECONDARY outcome
Timeframe: DeliveryPopulation: No samples were received which were sufficient to allow PCR testing after antibody testing.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: DeliveryPopulation: The population numbers reflect the samples received which were suitable for rtPCR testing. No placental samples were received from participants in the Unexposed or Vaccinated arms, so these were not analysed.
Outcome measures
| Measure |
Exposed
n=109 Participants
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation regardless of antibody status.
|
Unexposed
n=15 Participants
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation.
|
Vaccinated
Expectant mothers with a negative nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who received a vaccine against SARS-CoV-2 prior to delivery.
|
Vaccinated and Exposed
Expectant mothers with a positive nasopharyngeal swab for SARS-CoV-2 at any point during pregnancy from 24 weeks gestation who also received a vaccine against SARS-CoV-2 prior to delivery.
|
|---|---|---|---|---|
|
Placental Samples That Are rtPCR Positive
|
1 No. of Placental Samples rtPCR positive
|
0 No. of Placental Samples rtPCR positive
|
—
|
—
|
SECONDARY outcome
Timeframe: DeliveryPopulation: All PCR placental samples were negative at delivery, except for one swab which was determined to have likely been contaminated in the delivery room. As all other samples were negative, none proceeded to in vitro culture.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: DeliveryPopulation: No breastmilk samples were PCR positive, therefore none proceeded to in vitro culture.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: 6 weeks post deliveryPopulation: No paired samples proceeded to in vitro culture due to lack of PCR positivity.
Outcome measures
Outcome data not reported
Adverse Events
Exposed
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Unexposed
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Vaccinated
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Vaccinated and Exposed
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place