Neonatal outcomes after influenza immunization during pregnancy: a randomized controlled trial

BACKGROUND: There are limited data about the effect of maternal influenza infection on fetuses and newborns. We performed a secondary analysis of data from the Mother's Gift project, a randomized study designed to test the effectiveness of inactivated influenza and pneumococcal vaccines during pregnancy. METHODS: In the Mother's Gift project, 340 pregnant women in Bangladesh received either inactivated influenza vaccine or 23-valent pneumococcal polysaccharide vaccine (control). This study was performed from August 2004 through December 2005. We performed a secondary analysis of outcomes following maternal influenza immunization during two periods: when influenza virus was not circulating (September 2004 through January 2005) and when influenza virus was circulating (February through October 2005). We assessed gestational age, mean birth weight and the…