Women who undergo weight-loss surgery, known as bariatric surgery, and later become pregnant after losing weight may be at lower risk for pregnancy-related diabetes and high blood pressure-- complications that can seriously affect the mother or her baby--than pregnant women who are obese, according to new findings from the Agency for Healthcare Research and Quality that are published in the November 19 issue of JAMA, the Journal of the American Medical Association.
The findings are part of an evidence review that was led by Melinda A. Maggard, M.D., of the University of California at Los Angeles and the RAND Corporation in Santa Monica, CA, and performed by AHRQ's Southern California Evidence-Based Practice Center at RAND. The review was based on findings from 75 studies, including three that compared pregnancies of non-obese women to those of obese women as well as to pregnancies of women who lost weight surgically. The evidence review was conducted at the request of the American College of Obstetricians and Gynecologists.
In one study of laparoscopic gastric banding, a type of bariatric surgery, the authors found that none of the women who underwent surgery developed gestational diabetes or high blood pressure during their pregnancies. By comparison, 22 percent of obese pregnant women developed diabetes and 3 percent developed high blood pressure in the same study. Thirteen other studies supported these findings. Neonatal outcomes, like preterm delivery, low birth weight, and high birth weight, were also likely to be better in pregnancies of women following bariatric surgery than in pregnancies of obese women.
"Women of childbearing age who are considering weight-loss surgery should talk to their doctors about the implications for the future," said AHRQ Director Carolyn M. Clancy, M.D. "While we don't have all the answers yet, these preliminary findings may help physicians guide their patients. "
More than 50,000 women a year ages 18 to 45 undergo bariatric surgery procedures that include gastric bypass surgery, vertical-banded gastroplasty, and other inpatient weight-reduction procedures. Others have outpatient laparoscopic adjustable gastric banding procedures.
Dr. Maggard said, "Although no randomized controlled trials were found that specifically assessed pregnancy outcomes following surgery, the existing body of evidence revealed that, in general, some maternal and neonatal complications appear lower in pregnancies following bariatric surgery as compared to pregnancies in obese women." Dr. Maggard added that their rates even approach those seen in pregnancies in non-obese women.
The evidence report also found that: