Mothers who have weight-loss surgery before pregnancy may have thinner children, a new study suggests.

Weight-loss surgery can break the "obesity cycle," in which obese mothers will have children who are likely to be obese, according to the study published by Health Day News on Wednesday.

The study was conducted by the State University of New York Downstate Medical Center in Brooklyn.

Researchers found that women who had weight-loss surgery before becoming pregnant had children who were less likely to be heavy when compared with siblings who were born before the weight-loss surgery.

The researchers studied 49 mothers who had had biliopancreatic diversion surgery and their 111 children, aged 2.5 to 25 years. All of the mothers included in the study had children before and after their weight-loss surgery.

The study focused on women who underwent a weight-loss procedure called biliopancreatic diversion before becoming pregnant. The procedure alters digestion by making the stomach smaller and directing food to bypass part of the small intestine, resulting in absorption of fewer calories.

The study authors found that children who were born after their mother's weight-loss surgery had lower birth weight and waist circumference and were three times less likely to become severely obese than their older siblings.

The younger siblings also had improved cardiovascular markers, including reduced insulin resistance and lower cholesterol, the researchers found.

The study findings show the importance of the intrauterine environment, which seems to trump even genes and the environment in which the child is raised, the researchers noted.

Previous studies of obese pregnant women have shown that obesity and its related health problems can be passed on to children, which indicates that the intrauterine environment may determine whether a child is destined for obesity.

"Our study confirms previous research showing that the intrauterine environment may be more important than genes and the postnatal environment when it comes to the association between maternal obesity and childhood obesity," said study co-author Dr. John Kral.

"Any medical or surgical treatment to reduce obesity and existing metabolic disorders before pregnancy can be an investment in the life of future offspring," Kral added.

(Xinhua News Agency September 3, 2009)