Neonatal and Maternal Outcomes of mRNA Compared With Non-mRNA Vaccinations in Pregnant Patients With COVID-19: A Systematic Review and Meta-Analysis [ID 2683437

Abstract

INTRODUCTION: COVID-19 infection in pregnancy poses risks such as preeclampsia, preterm birth, and stillbirth, even when asymptomatic. Vaccination is recommended, but hesitancy exists because of limited pregnancy-related data. Notable vaccines in the United States considered safe in pregnancy are Pfizer and Moderna, two mRNA vaccines, and Johnson & Johnson, an adenovirus vaccine. We aimed to investigate the safety profile of mRNA versus non-mRNA vaccines, and if a particular vaccine type offered superior care. METHODS: We systematically searched Pubmed, Embase, and Cochrane Central for studies comparing mRNA and non-mRNA vaccines. RevMan5 and RStudio were used for statistical analyses. RESULTS: We included eight observational studies, with a total of 32,153 patients assessed for maternal and neonatal outcomes. Overall, mRNA vaccines had lower incidence of fetal death outcomes (P<.00001), and non-mRNA vaccines had lower incidence of fever (P<.00001). In subgroup analyses, the J&J vaccine (Ad26.COV2.S) was less associated with premature labor/delivery (P=.09) and missed/spontaneous abortion (P=.02) when compared to Pfizer. Leave-one-out analysis favored mRNA vaccines in reducing the risk of fetal or neonatal death and still favored non-mRNA vaccines for minimizing pyrexia, expressing low heterogeneity. CONCLUSION: This meta-analysis changes our current perspective on the safety profile of mRNA vaccines, providing insightful information, because the use of certain vaccine classes may benefit women prone to certain events, such as recurrent pregnancy loss or with a history of premature labor/delivery.