Pregnancy and Fertility after Bariatric Surgery

Today I am presenting a talk on obesity at the 54th Annual Meeting of the Canadian Fertility and Andrology Society, being held in Calgary, Alberta. The reason that I’ve been invited, is because, as many of you know, excess weight has a significant negative effect on fertility rates. Indeed, obesity may today be by far the most frequent cause of failure to conceive.

While my talk is on the general approach to obesity diagnosis and management, it is timely that in this week’s issue of JAMA, Melinda Maggard et al. from the University of California, Los Angeles, CA, publish a systematic review on pregnancy and fertility following bariatric surgery.

For their review, Maggard and colleagues searched the Nationwide Inpatient Sample (1998-2005) and multiple electronic databases to identify articles published between 1985 and February 2008 on bariatric surgery among women of reproductive age. Of 260 screened articles, 75 were included. Women aged 18 to 45 years accounted for 49% of all patients undergoing bariatric surgery (>50,000 cases annually for the 3 most recent years).

Matched cohort studies showed lower maternal complication rates after bariatric surgery than in obese women without bariatric surgery, or rates approaching those of nonobese controls. Rates of gestational diabetes (0% vs 22.1%, P < .05) and preeclampsia (0% vs 3.1%, P < .05) were lower in the bariatric surgery patients. These findings were supported by 13 other bariatric cohort studies.

Neonatal outcomes were similar or better after surgery compared with obese women without laparoscopic adjustable gastric band surgery (7.7% vs 7.1% for premature delivery; 7.7% vs 10.6% for low birth weight, P < .05; 7.7% vs 14.6% for macrosomia, P < .05).

Unfortunately, studies regarding nutrition, fertility, cesarean delivery, and contraception were limited.

For e.g. on the issue of fertility, the authors identified 6 studies generally showing improved fertility, although due to lack of a denominator (the number of women actually trying to get pregnant), the impact of surgery is hard to determine. Nevertheless, data clearly shows improvements to complete disappearance of polycystic syndrome and normalization of hormonal patterns and return of normal menstrual cycles.

On the issue of contraception there are isolated reports of failure of contraception following bypass surgery – systematic or controlled trial are lacking.

In summary, the authors concluded that the rates of many adverse maternal and neonatal outcomes may be lower in women who become pregnant after having had bariatric surgery compared with rates in pregnant women who are obese; however, as almost always in this rapidly evolving field of medicine, further data are needed from rigorously designed studies.

Clearly, the good news is that bariatric surgery is not a barrier to having healthy babies – babies, which, as we know from other studies, may in fact have a far lower risk for future obesity, than babies from severely obese mothers, who have not undergone bariatric surgery before pregnancy.

Edmonton, Alberta

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