Fell DB et al. Am J Public Health. 2012 Jun;102(6):e33-40. Epub 2012 Apr 19.

A Canadian study, based on a database that included 55,570 women who gave birth during the 2009-2010 influenza pandemic, investigated the effect of the vaccination on their babies.  42% of them were vaccinated against H1N1 during the second or third trimester. Vaccinated mothers had lower chances of delivering small for gestational age babies, pre-term birth and fetal mortality compared to unvaccinated women. The researchers concluded that vaccination during pregnancy during the influenza pandemic was associated with better neonatal outcomes and that there is a need for more research to further elucidate this conclusion.