A study published on bmj.com today reports that obese women who undergo bariatric surgery before having a baby have a much lower risk of developing serious health problems during pregnancy.

Hypertensive disorders during gestation are a common cause of pregnancy complications and infant death. They affect about 7 percent of all pregnancies in the United States. Obesity, particularly extreme obesity, is a risk factor for hypertensive disorders in expectant mothers. These include serious conditions such as pre-eclampsia, where abnormally high blood pressure and other disturbances develop during pregnancy.

Bariatric surgery is an effective weight loss intervention for women with a body mass index (BMI) of 40 or more, or a BMI of 35 to 40 with associated conditions like diabetes. However, the impact of surgery on hypertensive disorders in pregnancy is unclear.

In order to find out more, researchers from Johns Hopkins University in the United States set out to test the theory. Did women who had a delivery after bariatric surgery have lower rates of hypertensive disorders in pregnancy compared with women who had a delivery before surgery?

Using insurance data from 2002-2006, they identified 585 obese women aged 16 to 45 years who had undergone bariatric surgery. These women had at least one pregnancy and delivery. They also had continuous medical insurance coverage during pregnancy plus two weeks after delivery.

Of these women, 269 had surgery before delivery and 316 had surgery after delivery.

Findings indicated that women who delivered after surgery had substantially lower rates (75 percent) of hypertensive disorders compared with women who delivered before surgery. This was true even after adjusting for factors such as age at delivery, multiple pregnancy, surgical procedure, pre-existing diabetes, and insurance plan.

The authors note that these results have important clinical, public health, and policy implications. For instance, bariatric surgery could be considered in women of childbearing age who wish to start a family, and have a BMI of 40 or more, or a BMI of 35 to 40 with associated conditions.

They write in closing that future research should also concentrate on long term maternal and child health after pregnancies and deliveries following bariatric surgery. Weight management, nutritional status, and burden of long term chronic disease should be considered.

“Impact of bariatric surgery on hypertensive disorders in pregnancy: retrospective analysis of insurance claims data”
Wendy L Bennett, assistant professor, Marta M Gilson, assistant professor, Roxanne Jamshidi, assistant professor, Anne E Burke, assistant professor, Jodi B Segal, associate professor, Kimberley E Steele, assistant professor, Martin A Makary, associate professor, Jeanne M Clark, associate professor
BMJ 2010; 340:c1662
doi:10.1136/bmj.c1662
bmj.com

Written by Stephanie Brunner (B.A.)