Obesity in pregnancy may increase the risk of heart defects in babies, according to a new study.
　　In the study, U.S. researchers compared the records of mothers of 7,392 children born with major heart defects and more than 56, 000 mothers of infants born without birth defects.
　　The study found that the heavier a woman is, the greater the risk of heart defects in babies.
　　On average, obesity is associated with a 15 percent increased risk of having a baby with a heart defect. But the risk rises with the level of obesity. Compared to normal-weight women, the risk is 11 percent higher in moderately obese women and 33 percent higher in morbidly obese women.
　　Because the study looked at the records of infants after they were born, it doesn’t conclusively prove that obese women who lose weight before becoming pregnant will reduce their risk of having a baby with a heart defect, the researchers noted.
　　The heavier a woman is, the greater the danger of heart defects in babies, concluded the study published in the April issue of the American Journal of Clinical Nutrition.
　　In general, women who were overweight but not obese had no increased risk, said the researchers at the U.S. National Institute of Child Health and Human Development (NICHD) and the New York State Department of Health.
　　"The trend is unmistakable: the more obese a woman is, the more likely she is to have had a child with a heart defect," study first author Dr. James L. Mills, of the NICHD’s Division of Epidemiology, Statistics and Prevention Research, said in a news release published on Friday by HealthDay News.
　　"The current findings strongly suggest that by losing weight before they become pregnant, obese women may reduce the chances that their infants will be born with heart defects," said Dr. Alan E. Guttmacher, acting director of the NICHD.
　　However, "if a woman is obese, it makes sense for her to try to lose weight before becoming pregnant," Mills said. "Not only will weight loss improve her own health and that of her infant, it is likely to have the added benefit of reducing the infant’s risk for heart defects."