This interim guidance has been updated to replace previously posted guidance entitled "Considerations Regarding Novel H1N1 Flu Virus in Obstetric Settings", dated July 6, 2009. This document clarifies clinical considerations related to management of suspected or confirmed maternal infection with 2009 H1N1 influenza virus infection within labor and delivery, postpartum, and newborn care settings in hospitals. A cautious approach to the management of ill mothers and their newborns is still recommended, but several options are provided based on hospital configuration, staffing, and surge capacity.