Risk of maternal and newborn complications may be lower after bariatric surgery

November 19, 2008

A review of previously published studies suggests that rates of adverse outcomes for mothers or pregnant women and newborn babies, such as gestational diabetes and low birth weight, may be lower after bariatric surgery compared with pregnant women who are obese, according to an article in the November 19 issue of JAMA.

"Obesity has reached epidemic levels in the United States and is a leading cause of health-related disorders. Rates of surgical weight loss procedures have grown steeply and women account for many of these patients. Large numbers of women in their childbearing years may undergo bariatric surgery, which may change fertility following weight loss, alter nutritional requirements during pregnancy, or impact contraception to prevent pregnancy," the authors write.

Melinda A. Maggard, M.D., M.S.H.S., of the Rand Corporation, Santa Monica, Calif., and colleagues conducted a review of articles on bariatric surgery among women of reproductive age to estimate the incidence of bariatric surgery among these women and to assess associations of bariatric surgery with pregnancy outcomes. The researchers identified 75 articles for inclusion in the review.

An analysis of the data indicated that the incidence of bariatric surgery in the U.S. increased by 800 percent between 1998 and 2005 (from 12,480 to 113,500 cases). Women accounted for 83 percent of procedures in the 18- to 45-year age group, and between 2003 and 2005, more than 50,000 women in this age group underwent inpatient bariatric surgery procedures annually (49 percent of all bariatric surgery cases). A review of several of the studies showed lower maternal complication rates after bariatric surgery than in obese women without bariatric surgery, or rates approaching those of nonobese controls. Gestational diabetes (0 percent vs. 22.1 percent) and preeclampsia (0 percent vs. 3.1 percent) were lower in the bariatric surgery group than in the obese comparison group. Maternal weight gain was reduced in the surgical group.

Newborn outcomes were similar or better after surgery compared with obese women without laparoscopic adjustable gastric band surgery (7.7 percent vs. 7.1 percent for premature delivery; 7.7 percent vs. 10.6 percent for low birth weight; 7.7 percent vs. 14.6 percent for macrosomia [overly large body]). No differences in these newborn outcomes were found after gastric bypass compared with nonobese controls.

"Research is needed to better delineate the extent to which surgery and subsequent weight loss improve fertility and pregnancy outcomes. Optimizing success for contraception and producing healthy neonates following surgery will require a multidisciplinary effort by surgeons, primary care physicians, reproductive fertility specialists, obstetricians, and patients," the authors conclude.

Source: JAMA and Archives Journals