Pregnancy : H1N1 History Increases Premature Birth Risk

Women with a history of infection with the H1N1 influenza virus appear to be 2 1/2 times more likely to give birth prematurely, according to research by the Japan Association of Obstetricians and Gynecologists.

According to the association, 5.8 percent of pregnant women gave birth prematurely in 2008, but the rate was 14.6 percent among those who had contracted the new type of influenza.

A total of 234 pregnant women were hospitalized due to H1N1 at 2,611 hospitals or clinics nationwide from May 2009 to March. Of the 178 of these whose delivery dates are known, 26 gave birth between the 22nd and 36th week of pregnancy, which is considered premature. The association has warned pregnant women to avoid infection with the H1N1 virus.

Pregnant women, along with diabetics and those with asthma, tend to develop severe symptoms when they catch H1N1, according to the World Health Organization.

© 2010, The Yomiuri Shimbun. Distributed by Mclatchy-Tribune News Service.