COVID-19 vaccination during pregnancy and adverse perinatal outcomes: a systematic review and meta-analysis.

We aimed to estimate the associations between coronavirus disease 2019 (COVID-19) vaccination during pregnancy and the risks of adverse perinatal outcomes. We performed a literature search in PubMed, Web of Science and Embase to identify eligible studies published up to 24 September 2023, yielding 39 included studies. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated with a random effects model. The pooled results showed that COVID-19 vaccination during pregnancy (any type or dose of COVID-19 vaccination during any trimester) was not associated with an increased risk of adverse perinatal outcomes. In particular, COVID-19 vaccination in the third trimester was associated with a decreased risk of preterm birth (<37 weeks) (RR 0.85 [95% CI 0.74 to 0.98]), 5-min Apgar <7 (RR 0.87 [95% CI 0.78 to 0.97]) and neonatal intensive care unit (NICU) admission (RR 0.90 [95% CI 0.86 to 0.95]). The inverse associations were also found in analysis of one-dose vaccination during pregnancy and the risk of miscarriage (RR 0.83 [95% CI 0.72 to 0.96]) and preterm birth (<37 weeks) (RR 0.90 [95% CI 0.80 to 1.00]) and two-dose vaccination during pregnancy and the risk of NICU admission (RR 0.86 [95% CI 0.76 to 0.96]). COVID-19 vaccination during pregnancy does not increase the risk of negative outcomes for the mother or baby.