Trial Outcomes & Findings for Assessing the Mother-to-infant Transmission Capabilities of COVID-19 Infection Among Pregnant Women in Ontario, Canada (NCT NCT04913948)

Last Updated: 2025-04-25

Results Overview

Evidence of SARS-CoV-2 RNA or antibodies against SARS-CoV-2 from a sterile (amniotic fluid) or non-sterile sample (nasopharyngeal swab sample, placental tissue, subamniotic swab or by cord blood serology \[for IgM or IgA\]) collected during the maternal hospital admission for delivery (specific time frame varied per participant).

Recruitment status

COMPLETED

Target enrollment

246 participants

Primary outcome timeframe

During the delivery admission

Results posted on

2025-04-25

Participant Flow

Participant milestones

Participant milestones
Measure	Pregnant Pregnant women with confirmed COVID-19 at any point during pregnancy or suspected (as identified at local hospital) of COVID-19 at time of delivery, who will be delivering at a participating hospital No intervention: No intervention
Overall Study STARTED	246
Overall Study COMPLETED	242
Overall Study NOT COMPLETED	4

Reasons for withdrawal

Reasons for withdrawal
Measure	Pregnant Pregnant women with confirmed COVID-19 at any point during pregnancy or suspected (as identified at local hospital) of COVID-19 at time of delivery, who will be delivering at a participating hospital No intervention: No intervention
Overall Study Withdrawal by Subject	2
Overall Study Sample processing issues	1
Overall Study Suspected to have COVID-19 at the time of delivery but was found to be negative upon RT-PCR testing	1

Baseline Characteristics

Assessing the Mother-to-infant Transmission Capabilities of COVID-19 Infection Among Pregnant Women in Ontario, Canada

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Pregnant n=242 Participants Pregnant women with confirmed COVID-19 at any point during pregnancy or suspected (as identified at local hospital) of COVID-19 at time of delivery, who will be delivering at a participating hospital No intervention: No intervention
Age, Continuous	31.2 years STANDARD_DEVIATION 5.3 • n=5 Participants
Sex: Female, Male Female	242 Participants n=5 Participants
Sex: Female, Male Male	0 Participants n=5 Participants
Race/Ethnicity, Customized Caucasian	69 Participants n=5 Participants
Race/Ethnicity, Customized Asian	35 Participants n=5 Participants
Race/Ethnicity, Customized Black	43 Participants n=5 Participants
Race/Ethnicity, Customized Other/Unknown/Mixed ethnicity	20 Participants n=5 Participants
Race/Ethnicity, Customized Missing	75 Participants n=5 Participants
Neighbourhood family income quintile Quintile 1 (lowest)	60 Participants n=5 Participants
Neighbourhood family income quintile Quintile 2	48 Participants n=5 Participants
Neighbourhood family income quintile Quintile 3	40 Participants n=5 Participants
Neighbourhood family income quintile Quintile 4	34 Participants n=5 Participants
Neighbourhood family income quintile Quintile 5	28 Participants n=5 Participants
Neighbourhood family income quintile Missing	32 Participants n=5 Participants
Pre-pregnancy BMI <18.5	6 Participants n=5 Participants
Pre-pregnancy BMI 18.5 to <25	93 Participants n=5 Participants
Pre-pregnancy BMI 25 to >30	68 Participants n=5 Participants
Pre-pregnancy BMI >=30	67 Participants n=5 Participants
Pre-pregnancy BMI Missing	8 Participants n=5 Participants
Gestational weight gain Less than recommended	50 Participants n=5 Participants
Gestational weight gain Within recommended range	43 Participants n=5 Participants
Gestational weight gain More than recommended	112 Participants n=5 Participants
Gestational weight gain Missing	37 Participants n=5 Participants
Parity Nulliparous	50 Participants n=5 Participants
Parity Primiparous	43 Participants n=5 Participants
Parity Multiparous	112 Participants n=5 Participants
Parity Missing	37 Participants n=5 Participants

PRIMARY outcome

Timeframe: During the delivery admission

Population: The rate of perinatal transmission of SARS-CoV-2 was estimated based on one or more positive test results by RT-PCR for SARS-CoV-2 from a sterile (amniotic fluid) or non-sterile sample (nasopharyngeal swab sample, placental tissue, subamniotic swab) or by cord blood serology (for IgM or IgA). A total of 227 participant provided the appropriate samples for analysis.

Outcome measures

Outcome measures
Measure	Pregnant n=227 Participants Pregnant women with confirmed COVID-19 at any point during pregnancy or suspected (as identified at local hospital) of COVID-19 at time of delivery, who will be delivering at a participating hospital No intervention: No intervention
Rate of Perinatal Transmission of SARS-CoV-2	12.3 percentage of participants

PRIMARY outcome

Timeframe: During the delivery admission

Evidence of SARS-CoV-2 RNA or antibodies against SARS-CoV-2 in fetal tissues (i.e., amniotic fluid, placental tissue, sub-amniotic swab, cord blood) collected during maternal hospital admission for delivery (specific time frame varied per participant). Evidence of intrauterine transmission was determined using RT-PCR and serological analysis.

Outcome measures

Outcome measures
Measure	Pregnant n=227 Participants Pregnant women with confirmed COVID-19 at any point during pregnancy or suspected (as identified at local hospital) of COVID-19 at time of delivery, who will be delivering at a participating hospital No intervention: No intervention
Rate of Intrauterine Transmission of SARS-CoV-2	4.4 percentage of participants

Adverse Events

Pregnant

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

Dr. Darine El-Chaar

Ottawa Hospital Research Institute

Phone: (613) 737-8899

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place