In California, data were reported for 94 pregnant women, eight post-partum women, and 137 non-pregnant women of reproductive age who were hospitalized with 2009 H 1 N 1 influenza. Most patients who were pregnant (95%) were in the second or third trimester, and approximately one-third (34%) had established risk factors for complications from influenza other than pregnancy. As compared with early antiviral treatment (administered before or at two days after symptom onset) in pregnant women, later treatment was associated with admission to an intensive care unit or death (relative risk, 4.3). In all, 22% required intensive care, and 8% died [19] . The estimated rate of admission for pandemic H 1 N 1 influenza virus infection in pregnant women during the first month of the outbreak was higher than it was in the general population. Between 15 April and 16 June 2009, six deaths in pregnant women were reported to the Centre for Disease Control, USA; all were in women who had developed pneumonia and subsequent acute respiratory distress syndrome requiring mechanical ventilation [20] .