Impact on pregnancies in south Brazil from the influenza A (H1N1) pandemic: cohort study.

Introduction: The emergence of a new subtype of the influenza virus in 2009 generated interest in the international medical community, the media, and the general population. Pregnant women are considered to be a group at risk of serious complications related to the H1N1 influenza virus. The aim of this study was to evaluate the outcomes and teratogenic effects of pregnancies exposed to the H1N1 virus during the Influenza A epidemic that occurred in the state of Rio Grande do Sul in 2009.