Fewer Birth Defects After Bypass Surgery

A new study in JAMA will be quite important for thinking about pregnancy and severe obesity. That’s because pregnancies for women with severe obesity carry a high risk for complications. Birth defects are more common with obesity. They’re also more common with poor glucose control that’s more likely when a pregnant woman has obesity. But this new study finds that birth defects are less common for children born to women who’ve had gastric bypass surgery.

A Study of Matched Controls

Martin Neovius and colleagues studied the outcomes for 2,921 pregnancies in women with a history of gastric bypass. For their comparison group, they identified 30,573 women with BMI and diabetes matched to the presurgery status of the bypass group. Of course, after surgery the mothers in the active group had less obesity and better glucose control.

Thus, the researchers hypothesized that they would see fewer birth defects in the surgery group. And that’s exactly what they saw. In fact, they saw a third fewer. Commenting on these results, Ali Aminian (a surgeon who was not part of the study) told Endocrine Today:

The take-home message from this study would be that in order to have a healthier and less eventful pregnancy, the medical community should consider bariatric surgery before pregnancy in selected patients with severe obesity.

Broader Perspective

In a 2015 commentary for the New England Journal of Medicine, Aaron Caughey offered this perspective on bariatric surgery and pregnancy:

Bariatric surgery has the potential to reduce the risks of gestational diabetes and large-for-gestational-age neonates but is also associated with some risks in pregnancy. Decisions regarding bariatric surgery in women of reproductive age should take into account the benefits and risks associated with this not inconsequential procedure in terms of both pregnancy and long-term health.

A recent systematic review and meta-analysis in PLOS Medicine documented some of the risks for adverse perinatal outcomes with bariatric surgery. Those data make it clear that nutritional support is especially important for women who’ve had surgery.

But the bottom line here is clear enough. For women  severe obesity who wish to have children, bariatric surgery can be quite helpful. Without it, becoming pregnant can be more difficult and the risk of birth defects is significant. Furthemore, treating obesity in mothers before they have children can reduce the risk of obesity in the next generation. It’s not easy, but it is rewarding.

Click here for the study in JAMA and here for reporting on it from Endocrine Today.

Mother and Child, painting by Pablo Picasso / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.

October 18, 2019