GRAPEVINE, TEX. — Obese women who have bariatric surgery prior to pregnancy have less complicated gestations and their children are markedly less obese than are siblings born prior to the surgery, according to a Canadian study.
“Less obesity is not even the most important finding—it's the improvement in their metabolic condition. Children born after their mother's surgery had 30% less insulin resistance compared to their brothers and sisters born before the surgery,” Dr. Picard Marceau reported at the annual meeting of the American Society for Metabolic and Bariatric Surgery.
The implication of these findings is that the propensity to develop obesity and the metabolic syndrome is transmitted through the generations not only via genetic factors, but also epigenetically through the intrauterine environment, said Dr. Marceau of Laval University, Quebec City.
He and his coworkers studied 37 very obese mothers who collectively gave birth to 56 children prior to undergoing a biliopancreatic diversion with duodenal switch (BPD) for weight loss and another 54 children afterward. The investigators added another 10 morbidly obese women who had all 23 of their children prior to the BPD and 10 others who had all 19 of their children post surgery. Children born before the mother's bariatric surgery have been prospectively followed on average to age 19 years, while those born post surgery have been followed to age 10.
The mothers' preoperative body mass index averaged 48.5 kg/m
Bariatric surgery had a dramatic effect on the course of subsequent pregnancies. Pregnancies prior to surgery were marked by 12 cases of gestational diabetes, 9 of preeclampsia, and 15 of hypertension requiring antihypertensive therapy; pregnancies after surgery had none. Gestational weight gain averaged 13.8 kg/m
The birth weight of the children born after mom's surgery was 17% lower than that of their siblings born prior to surgery.
The effects of the salutary postsurgical intrauterine environment differed somewhat by sex. In boys, it was manifest mainly as less weight gain; boys born after the mother's surgery had an 86% lower prevalence of obesity than did their older brothers. But the main effects noted in girls born after the mother's surgery were a 40% reduction in insulin resistance and a 35% decrease in percent body fat compared with their sisters born presurgically.
The study was supported by the Canadian Institute of Health Research.