In a new study, researchers found that obese women who had weight loss surgery prior to becoming pregnant were 75% less likely to have pregnancy complications related to high blood pressure than women who had the surgery after pregnancy.
Researchers say about a third of women of reproductive age in the U.S. are obese, defined as having a body mass index (BMI, a measurement of weight in relation to height) over 30, and 6%-8% are morbidly obese, with a BMI over 40.
For many of these women, weight loss surgery, such as gastric bypass, is an effective weight loss option. But researchers say little is known about the impact of weight loss surgery on the risk of pregnancy complications.
In the study, published in British Medical Journal, researchers compared the risk of high blood pressure-related pregnancy complications in 585 obese women aged 16-45 who had weight loss surgery before or after pregnancy from 2002 to 2006.
Of these women, 269 had weight loss surgery before delivery and 316 had the surgery after delivery. Gastric bypass was the weight loss surgery choice for the majority (82%) of the women.
The results showed that nearly 15% of women who delivered before weight loss surgery had preeclampsia or eclampsia (the final stage of preclampsia if left untreated) compared to about 3% of women who had the surgery before delivery.
Overall, obese women who had weight loss surgery before pregnancy were 80% less likely to develop preeclampsia and eclampsia during pregnancy, and the risk of other blood pressure-related complications was also lower.
These lower rates of pregnancy complications were still evident after adjusting for the mother’s age at delivery, multiple pregnancy (twins or more), type of weight loss surgery, pre-existing diabetes, and type of health insurance.
Researcher Wendy L. Bennett, assistant professor at the Johns Hopkins University School of Medicine, and colleagues say the results suggest that weight loss surgery should be considered for women of childbearing age with a BMI of 40 or more or a BMI of 35 or more with associated health problems.
In addition, they say more study is needed to examine long-term maternal and child health after pregnancies and deliveries following weight loss surgery.