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

In order to assess the mother-to-infant and potential vertical transmission of SARS-CoV-2 infection in pregnant women, maternal and neonatal biological samples were prospectively collected from women with confirmed or suspected COVID-19 at participating hospitals. Samples were be tested for the SARS-CoV-2 serology and presence of SARS-CoV-2 RNA.

Outcomes for the study objective will be ascertained through the collection and testing of biological samples from the mother and/or infant. Specifically the investigators will:

1. Assess maternal nasopharyngeal or oropharyngeal swab, vaginal mucosa, ano-rectal swab, amniotic fluid, placenta (including subamniotic swab), breastmilk, cord blood and neonatal nasopharyngeal swab for RNA particles of coronavirus, by ddPCR.
2. Assess maternal serum for anti-coronavirus antibodies, by immunoassay.
3. Examine the impact of coronavirus on the neonate with respect to serology and viral load, in addition to placenta pathology findings and ddPCR.
4. Assess vertical transmission and the effect of coronavirus through placental pathology examination using placental pathology synoptic report.

Study Overview

• Status: Completed
• Conditions: Covid19; Pregnancy; Corona Virus Infection; SARS-CoV-2; Infectious Disease Transmission, Vertical
• Intervention / Treatment: Other: No intervention

Detailed Description

Pregnant individuals with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection were more likely to experience greater disease severity and higher rates of hospitalization, intensive care unit (ICU) admission and death compared to their non-pregnant counterparts. Early pandemic data were limited to a few small case series and reports that failed to provide a clear understanding of the timing and likelihood of fetal/neonatal infection. Data now suggest that in utero, intrapartum and early postnatal transmission of SARS-CoV-2 to the fetus/neonate is rare (<5%) and predominantly associated with third trimester infections and severe disease presentation. A living systematic review and meta-analysis of 144 cohort studies found that the rate neonates/fetuses testing positive for SARS-CoV-2 by RT-PCR, having anti-SARS-CoV-2 IgM antibodies or both was 1.94% (95%CI 1.31%, 2.66%). However, tests for SARS-CoV-2 and anti-SARS-CoV-2 antibodies were limited during the earliest stages of the pandemic and relatively few of the included studies provided sufficient data on the timing of fetal/neonatal exposure, and the type and timing of tests performed.

Derivation of reliable risk estimates for perinatal transmission remains challenging due to significant heterogeneity across published studies regarding the types of tissues profiled, diagnostic methods used and availability of essential COVID-19 disease characteristics such as timing and severity of maternal infection. As variants of concern continue to emerge, more data are required to elucidate the circumstances in which SARS-CoV-2 infection is likely to be transmitted to the developing fetus/neonate. We sought to evaluate the rate of SARS-CoV-2 transmission from mother-to-neonate in a large multicenter cohort from Ontario and Quebec, Canada.

To address early pandemic challenges in characterizing perinatal infections, a prospective cohort study was conducted across 14 sites in Ontario and Quebec, Canada. Pregnant individuals who had received a diagnosis of SARS-CoV-2 infection in pregnancy were eligible. Sample collection at delivery included maternal samples (nasopharyngeal/oropharyngeal, vaginal and anorectal swabs; blood; breastmilk), newborn samples (nasopharyngeal swabs, cord blood, amniotic fluid), and placental samples (sub-amniotic swab, placental biopsies). Swab, amniotic fluid, placenta and breastmilk samples were analyzed for SARS-CoV-2 RNA by RT-qPCR. Blood, breastmilk and amniotic fluid were assessed for anti-SARS-CoV-2 spike (S), receptor binding domain (RBD) and nucleocapsid (N) IgG, IgM and IgA.

• Study Type: Observational
• Enrollment (Actual): 246

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Hamilton, Ontario, Canada, L8L8E7
      • Hamilton Health Sciences Corporation
    • Kingston, Ontario, Canada, K7L 2V7
      • Kingston Health Sciences Centre
    • Kitchener, Ontario, Canada, N2G1G3
      • Grand River Hospital
    • London, Ontario, Canada, N6A5W9
      • London Health Sciences
    • North York, Ontario, Canada, M3M 0B2
      • Humber River Hospital
    • North York, Ontario, Canada, M2K1E1
      • North York General Hospital
    • Ottawa, Ontario, Canada, K1K0T2
      • Hôpital Montfort
    • Ottawa, Ontario, Canada, K1H8L6
      • The Ottawa Hospital - General Campus
    • Ottawa, Ontario, Canada, K1Y4E9
      • The Ottawa Hospital - Civic Campus
    • Toronto, Ontario, Canada, M5G1X5
      • Mount Sinai Hospital
    • Toronto, Ontario, Canada, M4N3M5
      • Sunnybrook Health Sciences Centre
    • Toronto, Ontario, Canada, M5B1W8
      • St. Michael's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Pregnant women meeting the study eligibility criteria and delivering at a participating hospital within Ontario or Quebec will be recruited. Hospitals within the COPE Network include both Level II and III hospitals.

Description

Inclusion Criteria:

• Pregnant women with confirmed COVID-19 at any point during pregnancy or suspected COVID-19 at time of delivery (as identified at local hospital) , who will be delivering at a participating hospital in Ontario or Quebec

Exclusion Criteria:

• None

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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	Other: No intervention; No intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of Perinatal Transmission of SARS-CoV-2	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).	During the delivery admission
Rate of Intrauterine Transmission of SARS-CoV-2	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.	During the delivery admission

Collaborators and Investigators

• Sponsor: Ottawa Hospital Research Institute
• Collaborators: Canadian Institutes of Health Research (CIHR)
• Investigators: Principal Investigator: Darine El-Chaar, MD, MSc, The Ottawa Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 30, 2020
• Primary Completion (Actual): July 31, 2021
• Study Completion (Actual): July 31, 2021

Study Registration Dates

• First Submitted: March 3, 2021
• First Submitted That Met QC Criteria: June 3, 2021
• First Posted (Actual): June 4, 2021

Study Record Updates

• Last Update Posted (Actual): April 25, 2025
• Last Update Submitted That Met QC Criteria: April 24, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Respiratory Tract Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Lung Diseases; Pneumonia, Viral; Pneumonia; Coronaviridae Infections; Nidovirales Infections; COVID-19; Infections; Communicable Diseases; Coronavirus Infections
• Other Study ID Numbers: CTO 2168

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: IPD that underlie the results reported in this article, after deidentification, will be made available to other researchers upon request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No