Bariatric operations reduce odds of gestational diabetes, caesarean section

Obese women who have bariatric surgical procedures before pregnancy were three times less likely to develop gestational diabetes (GDM) than women who have bariatric operations after delivery, according to new research findings published in the August issue of the Journal of the American College of Surgeons. The retrospective study also found that delivery after bariatric procedures was associated with reduced odds of caesarean section - an outcome associated with GDM.

Gestational diabetes affects at least seven percent of all pregnancies in the United States, with rates as high as 14 percent among certain populations. Its prevalence is increasing among reproductive-age women, parallel to increasing rates of obesity and type 2 diabetes. Currently, 33 percent of women over 19 years of age meet the criteria for obesity (body mass index [BMI] 30 kg/m2) and seven percent for extreme obesity (BMI 40 kg/m2). Bariatric surgical procedures are the only intervention shown to produce sustained weight reduction in the vast majority of subjects.

'The major finding of our study is that women who had bariatric surgery before they delivered reduced odds of gestational diabetes when compared with women had bariatric surgery after they delivered,' said Anne E. Burke, MD, MPH, assistant professor of obstetrics and gynaecology at the Johns Hopkins University School of Medicine in Baltimore, Md.

'Despite a growing body of evidence supporting the safety and efficacy of bariatric surgery in reversing obesity-related complications, few candidates for the procedure are referred to a surgeon to discuss their options,' stated Martin Makary, MD, MPH, associate professor of surgery at Johns Hopkins University School of Medicine and senior author of the study.

Researchers performed a retrospective study to compare rates of GDM and related outcomes between a group of women who had bariatric operations before pregnancy (n=346) and a group who had bariatric operations after delivery (n=354) between 2002 and 2006. Women who delivered after bariatric procedures had lower incidences of GDM (8 percent vs. 27 percent, odds ratio (OR) 0.23) and caesarean section (28 percent vs. 43 percent, OR 0.53) than those who delivered before bariatric procedures.

Women who delivered after bariatric operations were slightly older (32.5 years vs. 31.1 years, p 0.001). The median time from surgical procedure to delivery was 19.6 months, which meant that the majority of women did not adhere to the current recommendation to defer pregnancy for two years after bariatric procedures were performed. Deliveries before bariatric operations occurred at a median time of 16.5 months, meaning that most women waited more than a year after delivery before having bariatric procedures. The majority of women in each group had a bypass procedure (75 percent in the prebariatric delivery group and 87 percent in the postbariatric delivery group). Women who had a prebariatric delivery were more likely to have an adjustable banding procedure than women with a postbariatric delivery (9 percent vs. 3 percent).