Neonatal characteristics and outcomes of pregnancies complicated by influenza infection during the 2009 pandemic.

The purpose of this study was to describe the neonatal characteristics and outcomes of infants who were born during the 2009 H1N1 influenza pandemic. A prospective cohort of pregnant women with influenza-like illness (ILI) was enrolled between the months of June 2009 and March 2010. Neonatal characteristics, complications, and outcomes were recorded. Forty-five women were included in the study. Birth outcomes were available in 41 cases; 16 women had 2009 H1N1 infection, and the remaining 25 women who tested negative were included in the ILI group. Live births were similar in both groups. Average gestational age at delivery was >39 weeks; Apgar scores and cord gas pH values were similar. Birthweights in the 2009 H1N1 group were on average 285 g lower (3186 vs 3471 g; P = .04). Three infants were admitted to the neonatal intensive care unit. In this cohort, 2009 H1N1 infection during pregnancy was associated with a lower birthweight when compared with ILI in pregnancy.