A report published in the AJOG (American Journal of Obstetrics and Gynecology) claims no short-term side effects occurred in infants treated with oseltamivir or zanamivir during the 2009 flu pandemic in Japan. The study was completed by researchers in the Department of Obstetrics and Gynecology at the University of Toyama.

Data were collected from 157 out of 2,611 obstetric care providers part of the Japan Society of Obstetrics and Gynecology. The oseltamivir group consisted of 624 infants and 619 mothers. The zanamivir group consisted of 50 infants and 50 mothers. Mothers were given the antiviral drug during pregnancy as treatment for the flu.

After taking all factors into consideration, researchers found no increased risk of fetal malformation, stillbirth or spontaneous abortion among women given antiviral medications oseltamivir or zanamivir.

Source: Saito S, Minakami H, Nakai A, Unno N, Kubo T, Yoshimura Y. Outcomes of infants exposed to oseltamivir or zanamivir in utero during pandemic (H1N1) 2009. Am J Obstet Gynecol. 2013 Apr 9. pii: S0002-9378(13)00356-6. doi: 10.1016/j.ajog.2013.04.007.