O-256 Evaluation of Anti-Mullerian hormone levels in reproductive age severely obese women six months after bariatric surgery
Authors: Monteiro G , Auge A , Miklos T  G 
Published: July 2024

Study question

Do serum levels of anti-Müllerian hormone (AMH) change in women of reproductive age following weight loss induced by bariatric surgery?

Summary answer

Following six months post-bariatric surgery, despite substantial weight loss, both Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy patients exhibited consistent AMH levels.

What is known already

Obesity negatively affects fertility, IVF outcomes, and potentially AMH) levels. AMH correlates to the number of growing follicles and is currently the best measure of ovarian reserve. Bariatric surgery (BS) has been considered as the most effective method to achieve sustainable weight loss. Many studies have demonstrated that there is an increase of spontaneous pregnancies and a reduction in complications during pregnancy or delivery post-bariatric surgery. Despite these benefits, the specific impact of BS on ovarian reserve and AMH levels remains unclear. Several studies have already considered the effects of surgery-induced weight loss on ovarian reserve, often showing conflicting results.

Study design, size, duration

This prospective study included 22 obese women in reproductive age with BMI ≥ 40 or ≥ 35 kg/m2 with at least one obesity-related comorbidity at baseline and 6 months after undergoing either sleeve gastrectomy or Roux-en-Y gastric bypass (RYGB).

Participants/materials, setting, methods

Women aged 20–34 years with a median BMI of 41.53 kg/m² were included at baseline. Two medical consultations occurred: one preoperatively and another 6 months postoperatively. Each session included body weight and height measurements, as well as serum AMH testing using the Elecsys® AMH kit (Diagnostics Roche) and the electrochemiluminescence method - Cobas (Diagnostics Roche). Patients were divided into two groups: group 1 underwent RYGB, while group 2 underwent sleeve gastrectomy.

Main results and the role of chance

After six months post-bariatric surgery, all participants exhibited a significant reduction in BMI, with the median dropping from 41.53 kg/m² to 29.56 kg/m², representing a substantial 28.82% decrease (p &lt; 0.001). In Group 1, the median BMI decreased from 38.51 kg/m² to 29.27 kg/m², a statistically significant reduction of 27.30% (p = 0.003). Group 2 also saw a significant drop, from 42.53 kg/m² to 30.10 kg/m², reflecting a 29.23% reduction (p = 0.003). Contrastingly, no significant changes in AMH levels were noted six months post-bariatric surgery. The median AMH level slightly decreased from 3.02 ng/mL to 2.95 ng/mL, a non-significant 2.32% reduction (p = 0.783). In Group 1, the median AMH level increased insignificantly from 2.54 ng/mL to 2.92 ng/mL, a 14.96% rise (p = 0.424). In Group 2, there was a non-significant 6.88% decrease, from 3.20 ng/mL to 2.98 ng/mL (p = 0.722). Pre-surgery, 12 patients reported regular menstrual cycles, while 10 reported irregular cycles. After six months, a significant increase (p = 0.021) in patients with regular menstrual cycles was observed, with 19 reporting regular cycles, while only 3 continued to experience irregular cycles.

Limitations, reasons for caution

Several limitations of the study should be considered, including the small sample size and the relatively short six-month follow-up period. It would be valuable to compare the study participants with a control group of women who achieved weight loss through diet and exercise.

Wider implications of the findings

The convergence of BS and fertility is an area of significant interest and clinical impact. This study suggests that BS has no significant impact on AMH levels or ovarian reserve in short-term. However, extending the study’s follow-up period would provide valuable insights into the long-term effects on ovarian reserve.

Trial registration number

not applicable