This is a summary, written by members of the CITF Secretariat, of
McClymont E, Albert AY, Alton GD, Boucoiran I, Castillo E, Fell DB, Kuret V, Poliquin V, Reeve T, Scott H, Sprague AE, Carson G, Cassell K, Crane J, Elwood C, Joynt C, Murphy P, Murphy-Kaulbeck L, Saunders S, Shah P, Snelgrove JW, van Schalkwyk J, Yudin MH, Money D; CANCOVID-Preg Team. Association of SARS-CoV-2 Infection During Pregnancy With Maternal and Perinatal Outcomes. JAMA. 2022 May 2. doi: 10.1001/jama.2022.5906.
The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.
CITF-funded researcher Dr. Deborah Money, from the University of British Columbia, and the CANCOVID-Preg team published a study in JAMA, observing that SARS-CoV-2 infection during pregnancy was significantly associated with an increased risk of adverse maternal outcomes and preterm births in those who were unvaccinated. None of those pregnant who had received at least two doses of a COVID-19 vaccine experienced any adverse maternal outcomes.
- This analysis was before the Omicron variant predominated, and almost all cases of SARS-CoV-2 infection (98.7%) occurred among pregnant people who were previously unvaccinated. None of those pregnant who had received at least 2 doses of a vaccine experienced any adverse maternal outcomes.
- 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 Canadian population (7.75% vs 2.93%: relative risk, 2.65 [95% CI, 2.41-2.88]).
- The majority of those pregnant individuals who contracted SARS-CoV-2 were racialized individuals (62%), who self-identified as African, Black, Caribbean, East or Southeast Asian, or South Asian.
- Increasing age, pre-existing hypertension, and greater gestational age at diagnosis were significantly associated with adverse maternal outcomes.
- Those who were pregnant had an increased risk of intensive care unit/critical care unit admission due to COVID-19 compared to non-pregnant women (aged 20-49 years) with COVID-19 (2.01% vs 0.37%: relative risk, 5.46 [95% CI, 4.50-6.53]).
- Pregnant people with COVID-19 had a significantly higher risk of preterm birth compared to women with healthy pregnancies (11.05% vs 6.76%; relative risk, 1.63 [95% CI, 1.52-1.76]). Preterm birth occurred at an elevated rate, even in cases of mild disease not requiring hospitalization (9.3%).
The study presents data gathered in six Canadian provinces (638 residents in British Columbia, 2651 in Alberta, 312 in Manitoba, 529 in Quebec, 1874 in Ontario, and eight in Nova Scotia) covering March 1, 2020 to October 31, 2021, before the Omicron wave. A total of 6012 pregnant individuals with a positive SARS-CoV-2 polymerase chain reaction (PCR) test result at any time during their pregnancy (primarily due to symptomatic presentation) were compared with two groups of age-matched females, one with SARS-CoV-2 and the other unaffected pregnant people.