ABSTRACT
During periods of seasonal flu, pregnant women account for excess health care visits related to respiratory complaints and excess hospitalizations (above what would be expected outside of pregnancy); this is true for both healthy women and those with chronic conditions. The rate of hospitalization for seasonal (not pandemic) influenza among healthy nonpregnant women in Canada has been reported as 17/100,000, but 156/100,000 among healthy women who were pregnant. The 10-fold difference in influenza hospitalization persisted among women with comorbidities, but as expected the absolute rates are higher (53). Pregnant women are at increased risk for hospitalization during influenza season, and those hospitalized for respiratory illness stay longer (43,53,54). During the 2009 H1N1 influenza pandemic, pregnant and postpartum women with H1N1 influenza had a seven times higher risk of admission to ICU than nonpregnant women in the same age group, and after 20 weeks of pregnancy the relative risk of ICU admission was 13 times higher (52). The severity of disease is demonstrated by utilization of extracorporeal membrane oxygenation (ECMO): in 2009 in Australia and New Zealand, 16% of all ECMO interventions for respiratory failure in H1N1 were performed on pregnant or postpartum patients (55); these are patients whom conventional mechanical ventilation could not adequately oxygenate.
