Association of BNT162b2 SARS‐CoV‐2 vaccination during pregnancy with postnatal outcomes in premature infants

Aim The effect of COVID‐19 vaccine given during pregnancy on premature infants is unknown. This study aims to determine the association between maternal COVID‐19 vaccine with postnatal outcome in premature infants. Methods This is a single‐centre retrospective case–control study of infants born before 35 weeks gestation to mothers who received SARS‐CoV‐2 vaccine during pregnancy compared with infant born to non‐vaccinated mothers. Results A total of 78 infants in each group were included. Infants in the vaccinated group had less respiratory distress syndrome (RDS) ( p = 0.02) and less need for respiratory support ( p = 0.002), and maternal vaccine had a protective effect on RDS [adjustable OR 0.38 (0.17–0.85)]. Vaccination during the first compared to the second trimester was associated with earlier gestational age (32.3 ± 2.1 vs. 33.3 ± 1.1 weeks, p = 0.03). Conclusion We demonstrated that maternal SARS‐CoV‐2 vaccine is not associated with postnatal adverse effect in premature infants and potentially has a protective effect on RDS. Earlier gestational age among the infants born to mothers who received COVID‐19 vaccine during the first trimester did not translate to higher rate of postnatal complications. These findings might suggest that COVID‐19 vaccine is safe in high‐risk pregnancies, but timing of administration should be considered. Further studies are needed to confirm our findings and the biological mechanism.