Pregnancy Elevates the Risk of Severe COVID-19
A recent observational study conducted from 2021 to 2022 unveiled that a COVID-19 diagnosis during pregnancy heightened the risk of morbidity and mortality for pregnant individuals (relative risk [RR] 1.16, 95% confidence interval [CI] 1.03–1.31). Encouragingly, SARS-CoV-2 vaccination proved to be a protective shield against severe illness and fatalities. Unvaccinated pregnant individuals, on the other hand, faced a notably higher risk of morbidity and mortality (RR 1.36, 95% CI 1.12–1.65).
Increased Vulnerability of Infants Born to COVID-19 Positive Mothers
A systematic review and meta-analysis conducted in 2020 revealed that pregnant individuals afflicted with COVID-19 faced a heightened risk of stillbirth (odds ratio [OR] 1.81, 95% CI 1.38–2.37; absolute risk 351 stillbirths among 48,877 offspring [0.4%, 95% CI 0.2%–0.6%]) compared to those uninfected. Additionally, infants born to COVID-19-positive mothers exhibited an increased likelihood of admission to the neonatal intensive care unit (OR 2.18, 95% CI 1.46–3.26, absolute risk 3088 of 17,687 infants [25%, 95% CI 21%–30%]). An observational study during the Omicron period further underscored the elevated perinatal mortality risk for infants born to COVID-19-positive patients.
Safety of SARS-CoV-2 Vaccination During Pregnancy
Crucially, SARS-CoV-2 vaccination during pregnancy has not demonstrated an elevated risk of miscarriage, congenital anomalies, preterm delivery, or other adverse perinatal outcomes.
Reduction in Infant Hospital Admissions Due to COVID-19
Recent findings from a case–control test-negative study indicate that the effectiveness of the vaccine in preventing infant hospital admissions due to COVID-19 is 52% (95% CI 33%–65%) overall. Notably, its effectiveness was higher during the Delta wave (80%, 95% CI 60%–90%) and slightly lower during the Omicron wave (38%, 95% CI 8%–58%).
Recommendation: All mRNA SARS-CoV-2 Vaccines Approved for Use in Canada Are Safe During Pregnancy
It is crucial to note that all mRNA SARS-CoV-2 vaccines approved for use in Canada are recommended during pregnancy. Furthermore, SARS-CoV-2 vaccination is also encouraged for individuals planning to become pregnant and for those who are breastfeeding.
Competing Interests: Dr. Scott Halperin has reported contractual involvement in clinical trial research with various pharmaceutical companies, including GSK, Sanofi, Moderna, AstraZeneca, Pfizer, Merck, Entos, the Vaccine and Infectious Disease Organization, CanSino Biologics, and VBI Vaccines. He has served on ad hoc advisory boards for Merck, Sanofi, GSK, Pfizer, AstraZeneca, and Janssen, in addition to data safety monitoring boards for Medicago and IAVI. Dr. Halperin has also provided consultation services to the Province of Ontario and the Canadian Medical Protective Agency. No other competing interests were declared.
