Researchers found that children born to women who had weight-loss surgery before pregnancy have improved heart health and a lower risk of obesity compared with their siblings who were born before the mother had surgery. The study was published last week in the Journal of Clinical Endocrinology & Metabolism.
"Any obese mother or any mother gaining excessive weight during pregnancy puts her child at great risk," Kral says. "It's such a dramatic and substantial risk on so many levels. However, the prevalence of obesity in the children in our post-maternal surgery group was normal."
The researchers studied 49 women who had undergone weight-loss surgery and their 111 children, who were ages 2 to 25. About half of the women had given birth before the surgery and again after. The other women gave birth either before or after surgery.
The study showed that the children born after their mother's surgery had reduced birth weight and waist circumference and were three times less likely to become severely obese compared with siblings born before the surgery. These children also had improved cardiovascular markers, such as reduced insulin resistance and lower cholesterol and inflammation.
Some women, and even their doctors, worry that having weight-loss surgery before pregnancy may result in fetal malnutrition. But that is not the case, Kral says.
For women especially, the time to target weight-loss efforts is puberty, he says.
"The prevailing attitudes are still suspicious," he says. "But it's time for pediatricians and obstetricians not to sit on their hands any more and say 'obesity is going to go away. We'll wait until they're mature and take care of it then.' When everything else has failed -- the proper education, exercise and diet -- then you go to the next level of aggressiveness."
Earlier this year, the Institute of Medicine released updated guidelines that stress the importance of proper weight for young women and place limits on pregnancy weight gain. Obese pregnant women (body mass index of 30 or greater) are advised to gain 11 to 20 pounds.
"We don't have evidence to tell women if they have this surgery things are going to be better, for sure, with some kind of probability statement," said Dr. Kathleen M. Rasmussen, a professor of nutrition at Cornell University and chairwoman of the Institute of Medicine committee on pregnancy and weight. "We can say, in studies that have been done, women who have had bariatric surgery have not gained as much weight and that the risk of some disorders in the mothers, like diabetes and hypertensional disorders, might be less."
The data on the effects on babies whose mothers have had gastric bypass surgery are less clear, she said.
But, Rasmussen said: "Speaking for the committee, our position is women should begin pregnancy at a normal weight. We didn't specify how to do that. The easiest way is not get too heavy to start with. But for many women, it's too late."