Maternal first trimester COVID-19 vaccination and risk of major non-genetic congenital anomalies.

BACKGROUND:Information regarding the risk of early pregnancy COVID-19 vaccination on the development of major congenital anomalies in the offspring is still limited. Here, we study the association between any COVID-19 vaccination during the 1st trimester and at least one major non-genetic congenital anomaly in the offspring. METHODS:We used data from the Dutch Pregnancy Drug Register, an ongoing cohort study. We selected participants with a pregnancy that ended after at least 20 weeks gestation. Pregnant participants self-reported their COVID-19 vaccination status and the presence of congenital anomalies in the offspring. We used logistic regression analyses to study the association between 1st trimester COVID-19 vaccination (gestational week 2 + 0 to 12 + 6) and the risk of at least one major non-genetic congenital anomaly in the offspring. Clustering of anomalies on the ICD10 level by 1st trimester COVID-19 vaccination status was explored using Fisher exact tests. RESULTS:We included 3721 participants of whom 795 (21.4%) were COVID-19 vaccinated during the 1st trimester. The percentage of participants who gave birth to a child with at least one major non-genetic congenital anomaly was comparable between participants who were 1st trimester vaccinated (1.1%) and participants who were not (1.2%) (adjusted odd ratio 0.78 [95% confidence interval 0.35-1.71]). We found no clustering of major non-genetic congenital anomalies by 1st trimester COVID-19 vaccination status (p > .05). CONCLUSIONS:There were no indications of an increased risk of major non-genetic congenital anomalies in the offspring after maternal 1st trimester COVID-19 vaccination. Our findings suggest COVID-19 vaccines are safe during early pregnancy.