Maternal and neonatal outcomes after antepartum treatment of influenza with antiviral medications

Objective: To review the maternal and neonatal outcomes after antepartum exposure to M2 ion channel inhibitors or oseltamivir to provide some guidance on the risk, if any, of antiviral medication during pregnancy. Methods: This was a retrospective cohort study examining maternal and neonatal outcomes after antepartum exposure to antiviral therapy for influenza. We evaluated maternal characteristics, pregnancy outcomes, and fetal outcomes and compared them with our overall obstetric population. Results: Exposure to antiviral therapies (M2 ion channel inhibitors [n=104] compared with oseltamivir [n=135] compared with the control group [n=82,097]) during pregnancy was not associated with increased rates of preterm birth (7% compared with 10% compared with 6%, P=.190), premature rupture of membranes (23% compared with 16% compared with 22%, P=.154), gestational diabetes (4% compared with 8% compared with 6%, P=.388), or preeclampsia (6% compared with 1% compared with 4%, P=.209). Exposure was not associated with increased duration of hospital stay for mother or neonate. There were no differences in the incidence of minor malformations (19% compared with 15% compared with 22%, P=.101). Liveborn singletons without major malformations did not have differences in fetal weight (3,238±586 g compared with 3,281±642 g compared with 3,336±571 g, P=.186), need for intubation (2% compared with 0.8% compared with 1%, P=.552), intensive care nursery admission (3% compared with 3% compared with 2%, P=.418), or hyperbilirubinemia (12% compared with 9% compared with 8%, P=.282). Liveborn singletons had no grade 3 or 4 intraventricular hemorrhages, seizures, or neonatal deaths. Two preterm neonates exposed to different classes of medications had necrotizing enterocolitis (1.0% compared with 0.8% compared with 0.02%, P<.001). Conclusion: We found no evidence of an association between antepartum antiviral exposure and adverse outcomes.