Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2022 May 24;327(20):1983-1991.
doi: 10.1001/jama.2022.5906.

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

Elisabeth McClymont  1   2 , Arianne Y Albert  3 , Gillian D Alton  4   5 , Isabelle Boucoiran  6   7 , Eliana Castillo  8 , Deshayne B Fell  5   9 , Verena Kuret  8 , Vanessa Poliquin  10 , Tiffany Reeve  3 , Heather Scott  11 , Ann E Sprague  4   5 , George Carson  12 , Krista Cassell  11 , Joan Crane  13   14 , Chelsea Elwood  1   3 , Chloe Joynt  15 , Phil Murphy  13   14 , Lynn Murphy-Kaulbeck  16 , Sarah Saunders  17 , Prakesh Shah  18 , John W Snelgrove  19 , Julie van Schalkwyk  1 , Mark H Yudin  19 , Deborah Money  1   3 ; CANCOVID-Preg Team
Collaborators, Affiliations
Observational Study

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

Elisabeth McClymont et al. JAMA. .

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.

PubMed Disclaimer

Conflict of interest statement

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.

Figures

Figure 1.
Figure 1.. Bivariable Log-Binomial Models of Relative Risks for Hospitalization
Relative risks and 95% CIs from mixed-effects log-binomial regressions with province as a random effect. Body mass index is calculated as weight in kilograms divided by height in meters squared. See eFigure 3 in Supplement 1 for the model of relative risks for oxygen therapy.
Figure 2.
Figure 2.. Bivariable Log-Binomial Models of Relative Risks for Intensive Care Unit (ICU) Admission
Relative risks and 95% CIs from mixed-effects log-binomial regressions with province as a random effect. Body mass index is calculated as weight in kilograms divided by height in meters squared. See eFigure 3 in Supplement 1 for the model of relative risks for oxygen therapy.
Figure 3.
Figure 3.. Adverse Maternal Outcomes Associated With SARS-CoV-2 Diagnosis in Pregnancy From March 1, 2020, to October 31, 2021 (N = 6012)
Points are offset a small amount along the x-axis for visualization. Whiskers show 95% CI from binomial tests using a χ2 approximation. Eight completed pregnancies with missing dates are not included.
See this image and copyright information in PMC

References

    1. Wong SF, Chow KM, Leung TN, et al. . Pregnancy and perinatal outcomes of women with severe acute respiratory syndrome. Am J Obstet Gynecol. 2004;191(1):292-297. doi:10.1016/j.ajog.2003.11.019 - DOI - PMC - PubMed
    1. Shek CC, Ng PC, Fung GPG, et al. . Infants born to mothers with severe acute respiratory syndrome. Pediatrics. 2003;112(4):e254-e254. doi:10.1542/peds.112.4.e254 - DOI - PubMed
    1. Rasmussen SA, Smulian JC, Lednicky JA, Wen TS, Jamieson DJ. Coronavirus disease 2019 (COVID-19) and pregnancy: what obstetricians need to know. Am J Obstet Gynecol. 2020;222(5):415-426. doi:10.1016/j.ajog.2020.02.017 - DOI - PMC - PubMed
    1. Siston AM, Rasmussen SA, Honein MA, et al. ; Pandemic H1N1 Influenza in Pregnancy Working Group . Pandemic 2009 influenza A(H1N1) virus illness among pregnant women in the United States. JAMA. 2010;303(15):1517-1525. doi:10.1001/jama.2010.479 - DOI - PMC - PubMed
    1. Mosby LG, Rasmussen SA, Jamieson DJ. 2009 pandemic influenza A (H1N1) in pregnancy: a systematic review of the literature. Am J Obstet Gynecol. 2011;205(1):10-18. doi:10.1016/j.ajog.2010.12.033 - DOI - PubMed

Publication types

Grants and funding