The finding is concerning keeping in mind that the rate of Cesarean births in the United States increased 31.1 percent in 2006, from 20.7 percent of all births in 1996, according to health statistics cited in the study. According to the federal Centers for Disease Control and Prevention, nine in ten women who gave birth that way once have had another cesarean with subsequent births.

 

Study author Alan Tita, an assistant professor of obstetrics and gynecology at the University of Alabama at Birmingham, said, “There are definitely risks associated with delivering early.”

 

The study analyzed only women who chose to have cesareans and not those who had the surgery out of medical necessity. It involved 13,258 cesarean sections done at 19 medical centers from 1999 to 2002. The women had previously had at least one performed cesarean and didn’t have any complications in pregnancies.

 

Thirty-six percent of the C-sections took place before 39 weeks of gestation, the study found. Overall, about 10 percent of the babies at birth had at least one of the following problems: respiratory distress, low blood sugar, infection or need for a respiratory or intensive care. However, those born at 37 weeks were twice as likely and those born at 38 weeks 50 percent more likely to have a problem than those at 39. Study co-author Catherine Spong, of the National Institute of Child Health and Human Development, said women may not feel that there is a significant risk to the baby given that it’s only a 14 day difference between 37 and 39 weeks

 

“People might think the risks are small. It’s only a day or two, what does it really matter,” she said, but she also added that if the pregnancy is going well, the mother is not in labour and there is nothing pushing them to deliver early, then they should wait.

 

The American College of Obstetricians and Gynecologists, a nonprofit advocate for women’s health care says a normal pregnancy can last from 37 to 42 weeks, but the average length is 40 weeks. But the organization recommends waiting until the 39^th week of gestation for an elective C-section because the baby’s lungs should be fully developed by then. Despite this recommendation, some women opt to deliver a little earlier for a variety of reasons, including being eager to see their baby, being tired of pregnancy or for convenience.

 

The study was supported by the National Institute of Child Health and Human development.