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Association of SARS-CoV-2 Infection During Pregnancy With Maternal and Perinatal Outcomes

Educational Objective
To identify the key insights or developments described in this article
1 Credit CME
Key Points

Question  Is SARS-CoV-2 infection during pregnancy associated with increased risk of adverse maternal and perinatal outcomes?

Findings  This Canadian surveillance study included 6012 completed pregnancies between March 2020 and October 2021. Among cases of infection during pregnancy compared with cases of infection among the general Canadian population of reproductive-age female individuals, there was a significantly increased risk of SARS-CoV-2–related hospitalization (relative risk, 2.65) and intensive care unit admission (relative risk, 5.46). Among cases of infection during pregnancy compared with pregnant individuals without SARS-CoV-2 infection, there was a significantly increased risk of preterm birth (relative risk, 1.63).

Meaning  SARS-CoV-2 infection during pregnancy was significantly associated with increased risk of adverse maternal outcomes and preterm birth.

Abstract

Importance  There are limited high-quality, population-level data about the effect of SARS-CoV-2 infection on pregnancy using contemporaneous comparator cohorts.

Objectives  To describe maternal and perinatal outcomes associated with SARS-CoV-2 infection in pregnancy and to assess variables associated with severe disease in the pregnant population.

Design, Setting, and Participants  CANCOVID-Preg is an observational surveillance program for SARS-CoV-2–affected pregnancies in Canada. This analysis presents exploratory, population-level data from 6 Canadian provinces for the period of March 1, 2020, to October 31, 2021. A total of 6012 pregnant persons with a positive SARS-CoV-2 polymerase chain reaction test result at any time in pregnancy (primarily due to symptomatic presentation) were included and compared with 2 contemporaneous groups including age-matched female individuals with SARS-CoV-2 and unaffected pregnant persons from the pandemic time period.

Exposure  SARS-CoV-2 infection during pregnancy. Incident infections in pregnancy were reported to CANCOVID-Preg by participating provinces/territories.

Main Outcomes and Measures  Maternal and perinatal outcomes associated with SARS-CoV-2 infection as well as risk factors for severe disease (ie, disease requiring hospitalization, admission to an intensive care unit/critical care unit, and/or oxygen therapy).

Results  Among 6012 pregnant individuals with SARS-CoV-2 in Canada (median age, 31 [IQR, 28-35] years), the greatest proportion of cases were diagnosed at 28 to 37 weeks’ gestation (35.7%). Non-White individuals were disproportionately represented. Being pregnant was associated with a significantly increased risk of SARS-CoV-2–related hospitalization compared with SARS-CoV-2 cases among all women aged 20 to 49 years in the general population of Canada (7.75% vs 2.93%; relative risk, 2.65 [95% CI, 2.41-2.88]) as well as an increased risk of intensive care unit/critical care unit admission (2.01% vs 0.37%; relative risk, 5.46 [95% CI, 4.50-6.53]). Increasing age, preexisting hypertension, and greater gestational age at diagnosis were significantly associated with worse maternal outcomes. The risk of preterm birth was significantly elevated among SARS-CoV-2–affected pregnancies (11.05% vs 6.76%; relative risk, 1.63 [95% CI, 1.52-1.76]), even in cases of milder disease not requiring hospitalization, compared with unaffected pregnancies during the same time period.

Conclusions and Relevance  In this exploratory surveillance study conducted in Canada from March 2020 to October 2021, SARS-CoV-2 infection during pregnancy was significantly associated with increased risk of adverse maternal outcomes and preterm birth.

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CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.

Article Information

Corresponding Author: Deborah Money, MD, University of British Columbia, C425-4500 Oak St, Vancouver, BC V6H 3N1, Canada (deborah.money@ubc.ca).

Accepted for Publication: March 29, 2022.

Published Online: May 2, 2022. doi:10.1001/jama.2022.5906

Author Contributions: Drs McClymont and Albert had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: McClymont, Albert, Boucoiran, Castillo, Fell, Poliquin, Reeve, Sprague, Crane, Elwood, Murphy-Kaulbeck, Saunders, Shah, Snelgrove, van Schalkwyk, Yudin, Money.

Acquisition, analysis, or interpretation of data: McClymont, Albert, Alton, Fell, Kuret, Reeve, Scott, Sprague, Carson, Cassell, Crane, Elwood, Joynt, Murphy, Shah, Snelgrove, van Schalkwyk, Money.

Drafting of the manuscript: McClymont, Albert, Poliquin, Reeve, Money.

Critical revision of the manuscript for important intellectual content: Albert, Alton, Boucoiran, Castillo, Fell, Kuret, Scott, Sprague, Carson, Cassell, Crane, Elwood, Joynt, Murphy, Murphy-Kaulbeck, Saunders, Shah, Snelgrove, van Schalkwyk, Yudin, Money.

Statistical analysis: Albert, Alton, Fell.

Obtained funding: McClymont, Boucoiran, Kuret, Reeve, Elwood, Money.

Administrative, technical, or material support: McClymont, Alton, Boucoiran, Kuret, Poliquin, Reeve, Sprague, Cassell, Joynt, Snelgrove, van Schalkwyk, Money.

Supervision: Boucoiran, Elwood, Murphy-Kaulbeck, Yudin, Money.

Conflict of Interest Disclosures: Dr McClymont reported receiving salary support from a Michael Smith Foundation for Health Research Trainee Award and a Canadian HIV Trials Network Postdoc Fellowship. Dr Boucoiran reported receiving grants from Fonds de Recherche en Santé du Québec, Ferring, and the Quebec Health Ministry; receiving personal fees from Fonds de Recherche en Santé du Québec; receiving nonfinancial support from Altona; and participating in randomized clinical trials for GlaxoSmithKline and Pfizer. Dr Poliquin reported receiving honoraria/consultation fees from GlaxoSmithKline, Sanofi Pasteur, and Searchlight Pharma. Dr Sprague reported receiving funding from the Ontario Ministry of Health for BORN Ontario. Dr Elwood reported receipt of personal fees for board membership from Gilead. Dr Money reported receiving nonfinancial support from the COVID-19 Immunity Task Force and grants from the Canadian Institutes for Health Research (outside the submitted work), Merck, GlaxoSmithKline, Sanofi, and Novartis. No other disclosures were reported.

Funding/Support: This project was funded by the Public Health Agency of Canada (grant 2021-HQ-000100), the Canadian Institutes for Health Research (grant 447634), and the BC Women’s Health Foundation (grant 89026 7537 RR0001).

Role of the Funder/Sponsor: As part of the review and approval of the funding applications, the Public Health Agency of Canada, the Canadian Institutes for Health Research, and the BC Women’s Health Foundation approved the design, analysis, and conduct of the study. The funders had no role in the collection, management, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication.

Group Information: The CANCOVID-Preg Team members are listed in Supplement 2.

Additional Contributions: We acknowledge the contributing study staff (in alphabetical order): Arezou Azampanah, MSc (Women’s Health Research Institute; received compensation), Shamara Baidoobonso, PhD (Chief Public Health Office, Government of Prince Edward Island; did not receive compensation), Marc Beltempo, MD (Montreal Children’s Hospital and McGill University Health Centre; did not receive compensation), Suraya Bondy, BA (Women’s Health Research Institute; received compensation), Richard Brown, MD (McGill University; did not receive compensation), Emmanuel Bujold, MD (Université Laval; did not receive compensation), Suzanne Demers, MD (Université Laval; did not receive compensation), Karen Downing, RNBN (Women’s Health Research, Health Sciences Centre, Winnipeg; received compensation), Kaamel Hafizi, MSc (Children’s Hospital of Eastern Ontario Research Institute and Better Outcomes Registry and Network Ontario; did not receive compensation), Julie Hanna, BA (Women’s Health Research Institute; received compensation), Heather Hannah, DVM (Government of the Northwest Territories; did not receive compensation), James King, MSc (Alberta Health Services; did not receive compensation), Audrey Klassen, RN (University of Manitoba; received compensation), Carolina Lavin Venegas, MSc (Children’s Hospital of Eastern Ontario Research Institute and Better Outcomes Registry and Network Ontario; did not receive compensation), France Leduc, MD (Hôpital de la Cité-de-la-Santé & Université de Montréal; did not receive compensation), Isabelle Malhamé, MD (McGill University Health Centre; did not receive compensation), Fran Mulhall, RN (Health Sciences Centre Winnipeg; received compensation), Ali Nabeel, MD (Hôpital Maisonneuve-Rosemont; did not receive compensation), Donnette O’Brien, RN (Eastern Health; received compensation), Melanie Pastuck, BN (University of Calgary; received compensation), Bruno Piedboeuf, MD (CHU de Québec & Université Laval; did not receive compensation), Janet Slaunwhite (Dalhousie University; did not receive compensation), Suzanne Taillefer, PhD (CHU Sainte-Justine; did not receive compensation), Laurent H. Tordjman, MD (Université de Montréal and Hôpital Maisonneuve-Rosemont; did not receive compensation), Melissa Watt, CCRP (Women’s Health Research Institute; received compensation), Connie Williams, MD, PhD (McMaster University; did not receive compensation), and Bi Lan Wo, MD (Centre Hospitalier de l’Université de Montréal; did not receive compensation). We also acknowledge the Public Health Agency of Canada staff involved in the project (in alphabetical order; none received compensation): Susie Dzakpasu, PhD, Wei Luo, MSc, Stephanie Metcalfe, MSc, and Jay Onysko, MA.

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