We all witnessed the devastation that COVID-19 caused, but we also witnessed the hope provided by the rapid development of vaccines against this deadly virus.
One group at particular risk for serious COVID-19 disease were pregnant women; however, they were excluded from the early randomized controlled trials of the various vaccines. Subsequent observational studies demonstrated efficacy of COVID-19 vaccinations for this population, and since August 2021, COVID-19 vaccination during pregnancy has been explicitly recommended by leading medical associations.
However, the question of safety remains, especially during the first trimester when potential teratogenic effects are the most impactful.
This week, Pediatrics is early releasing an article and accompanying video abstract by Stacey Rowe, PhD, from University of California San Francisco and colleagues, entitled “COVID-19 Vaccination During Pregnancy and Major Structural Birth Defects” (10.1542/peds.2024-069778). In this study, the authors sought to evaluate the question of safety by comparing the prevalence of major structural birth defects based on whether the mother received COVID-19 vaccination during early pregnancy.
The authors identified a cohort of >78,000 pregnancies between August 2021 and September 2022 using 2 large insurance claims–based databases that provided information on vaccination status and timing, maternal comorbidities, and sociodemographic factors for both privately and publicly insured women.
Almost 13,000 women (16.3% of the cohort) received COVID-19 vaccination between 14 days before last menstrual period and 20 weeks of gestation, the time frame with the highest risk of any potential teratogenic effects.
The authors found:
- Median birth gestational age was 38 weeks for both vaccinated and unvaccinated people.
- No difference in the prevalence of major structural birth defects (160.6 per 10,000 live births among vaccinated people versus 156 per 10,000 live births among unvaccinated people), with a prevalence ratio of 0.97 (95% CI: 0.84-1.13) after adjusting for clinically significant potential confounders.
- Subgroup analyses by insurance provider, vaccine brand, SARS-CoV-2 infection during pregnancy, or co-administration with other maternal vaccines did not show demonstrable differences in prevalence ratios of major structural birth defects.
Although a limitation of the study is that it is based on retrospective insurance claims data with risk of misclassification of birth defects, the authors point out that they chose major structural defects as the outcome of interest as these are less likely to be misclassified. Additionally, COVID-19 vaccination status is unlikely to affect rates of misclassified outcomes.
We all know that safety is a major concern for patients when considering vaccinations for themselves and their families. But as the authors point out, the most impactful predictor of an individual’s decision to vaccinate during pregnancy is their provider’s recommendation.
Vaccinating against COVID-19 during pregnancy has already been proven effective in preventing infection in the mother and baby, and the results of this study can assist in reassuring providers and patients that it is also safe, even early in pregnancy. And this safety is not affected by vaccine brand, history of SARS-CoV-2 infection during pregnancy, or recent administration of other vaccines.
