Using a large population-based cohort, a study published in JAMA Pediatrics examined the association between maternal immunisation with BNT162b2, an mRNA COVID-19 vaccine, during pregnancy and neonatal and early infant outcomes, finding no detrimental outcomes in the offspring of vaccinated versus unvaccinated mothers.
The analysis included 24,288 singleton live births. The researchers calculated the risk ratios (RR) of preterm birth, small birth weight for gestational age (SGA), congenital malformations, all-cause hospitalisations, and infant death, adjusting for maternal age, the timing of conception, socioeconomic status, and other factors.
The results showed that, of the included newborns, 16,697 were exposed to maternal vaccination in utero (2,134 in the first trimester and 9,364 in the second trimester). No substantial differences were observed in preterm birth rates between exposed and unexposed newborns (RR 0.95).
Similarly, no significant differences were observed in the incidence of all-cause neonatal hospitalisations (RR 0.99), post-neonatal hospitalisations after birth (RR 0.95), congenital anomalies (RR 0.69), or infant mortality (RR 0.84).
These findings contribute to current evidence in establishing the safety of BNT162b2 for offspring. The authors concluded that these data could inform pregnant patients, couples planning pregnancy, and counselling physicians, therefore reducing vaccine hesitancy and increasing confidence among pregnant women.