A study published in Birth Defects Research examined outcomes of infants born to women who suffered from influenza during their pregnancy.
Researchers studied data collected by five state/local health departments on outcomes of infants born to pregnant women with H1N1 flu reported to the CDC between April and December 2009. They included 490 pregnant women who had the flu, 1,451 pregnant women who didn't have the in the same year; the study authors also included 1,446 pregnant women without reported flu that were pregnant in previous years.
The study shows that women with the flu admitted to intensive care unit (64 women) were more likely to deliver preterm infants and low birth weight infants than women in comparison groups.
However, women with the flu who were not hospitalized and hospitalized women who were not admitted to the ICU did not have significantly higher risks for adverse infant outcomes.