THURSDAY, Oct. 1, 2009 (HealthDay News) -- Overweight and obese women are more likely to give birth to babies with heart defects, a new study has found.
U.S. Centers for Disease Control and Prevention researchers analyzed data on 6,440 infants with congenital heart defects and 5,673 infants without heart defects whose mothers took part in the National Birth Defects Prevention Study.
Women who were overweight or obese before pregnancy were about 18 percent more likely than normal weight women to have a baby with certain kinds of heart defects, including obstructive defects on the right side of the heart and defects in the tissue that separates the two upper chambers of the heart. Severely obese women had a 30 percent increased risk compared to normal weight women, the study authors noted.
In reaching their findings, the researchers accounted for several important heart defect factors, including the mother's age and race/ethnicity. Women with diabetes before they became pregnant were excluded because diabetes in the mother is a strong risk factor for infant heart defects.
The study was published online Oct. 1 in the American Journal of Obstetrics & Gynecology.
"These results support previous studies, as well as provide additional evidence, that there is an association between a woman being overweight or obese before pregnancy and certain types of heart defects," primary study author Suzanne Gilboa, an epidemiologist at CDC's National Center on Birth Defects and Developmental Disabilities, said in an agency news release.
"This provides another reason for women to maintain a healthy weight. In addition to the impact on a woman's own health and the known pregnancy complications associated with maternal obesity, the baby's health could be at risk," Gilboa added.
"Congenital heart defects are the most common types of birth defect, and among all birth defects, they are a leading cause of illness, death, and medical expenditures," Dr. Edwin Trevathan, director of CDC's National Center on Birth Defects and Developmental Disabilities, said in the news release. "Women who are obese and who are planning a pregnancy could benefit by working with their physicians to achieve a healthy weight before pregnancy."
The study is the largest effort ever undertaken in the United States to identify risk factors for birth defects, the CDC said.
The March of Dimes has more about congenital heart defects.