Prenatal maternal inactivated COVID-19 vaccination: the maternal and neonatal outcomes, a retrospective cohort study

Abstract

Background There are very few data on the maternal and neonatal safety effects of inactivated COVID-19 vaccines. Several studies have reported the safety of SARS-CoV-2 vaccination during pregnancy, with no adverse effect on maternal and neonatal outcomes. However, data on the safety of prenatal vaccination are scarce. Therefore, more relevant data are needed to inform maternal, pregnancy, and infant outcomes. Objective To evaluate the prenatal maternal inactivated COVID-19 vaccination and the impact on maternal and neonatal outcomes. Methods A retrospective cohort study among women who delivered between January and June 2022 at the first affiliated hospital of wenzhou medical university. Those who have completed at least one dose of inactivated vaccine before or during pregnancy were included in “vaccinated group”, and those who were not vaccinated were included in “unvaccinated group”, the maternal, pregnancy and neonatal outcomes were evaluated. Propensity score matching (PSM) was performed to balance the baseline parameters of the two groups. Results A total of 1926 women were enrolled in this study, 827 (42.94%) women were prenatally vaccinated, and 1099 (57.06%) unvaccinated. The gestational week of delivery were slightly smaller in the vaccinated group, 38.77 ± 1.83 weeks in the vaccinated group and 39.01 ± 1.45 weeks in the unvaccinated group. There was a higher rate of overall preterm delivery in the vaccinated group (aOR 1.638, 95% CI 1.108–2.422; p = 0.013; Table 3, Fig. 2), however, the probability of delivery before 34 weeks and before 32 weeks (early preterm delivery) were similar (p > 0.05). A total of 2009 infants were born, 851 in the vaccinated group and 1158 in the unvaccinated group. There were similar neonatal outcomes in the two groups. Conclusions Although we found a slightly smaller gestational week of delivery and a possible increased rate of late preterm birth in the vaccination group, there was no difference in mean neonatal weight, incidence of low birth weight infants and other neonatal adverse complications. Meanwhile, there was no difference in pregnancy and maternal outcomes between the two groups.