COVID-19 vax in pregnancy not linked to adverse newborn, early infant outcomes

Receipt of mRNA COVID-19 vaccination during pregnancy does not appear to increase the incidence of adverse newborn and early infant outcomes and may even be protective, according to a study.

The study included 142,006 infants (mean gestational age at birth 38.7 weeks, 51 percent boys), of whom 85,670 (60 percent) were exposed to one or more COVID-19 vaccine doses in utero.

Researchers looked at outcomes including severe neonatal morbidity (SNM), neonatal death, neonatal intensive care unit (NICU) admission, neonatal readmission, and hospital admission up to 6 months of age. Cox proportional hazards regression models were used to compare these outcomes in infants of mothers who received COVID-19 vaccination during pregnancy with those who received no COVID-19 vaccine doses before delivery.

Multivariable models showed that exposure to COVID-19 vaccine in utero was associated with lower risks of SNM (7.3 percent vs 8.3 percent; adjusted RR [aRR], 0.86, 95 percent confidence interval [CI], 0.83–0.90), neonatal death (0.09 percent vs 0.16 percent; aRR, 0.47, 95 percent CI, 0.33–0.65), and NICU admission (11.4 percent vs 13.1 percent; aRR, 0.86, 95 percent CI, 0.83–0.89).

Maternal vaccination during pregnancy had no effect on neonatal readmission (5.5 percent vs 5.1 percent; adjusted hazard ratio [aHR], 1.03, 95 percent CI, 0.98–1.09) or 6-month hospital admission (8.4 percent vs 8.1 percent; aHR, 1.01, 95 percent CI, 0.96–1.05).

The findings expand on existing evidence regarding the safety of maternal mRNA vaccination during pregnancy for newborns and young infants.