Impact of Bariatric Surgery on Reproductive Hormones and Menstrual Regularity in Women with Obesity.

Abstract

Background: Obesity affects 2.5 billion adults, disrupting the hypothalamic-pituitary-ovarian (HPO) axis through adipokine imbalance and aromatase activity. This causes hormonal dysregulation, infertility, and pregnancy risks. Bariatric surgery can restore hormonal balance and improve menstrual regularity. This study evaluates post-bariatric surgery changes in reproductive hormones and cycle regularity over six months in Egyptian women with obesity.

Methods: This prospective cohort study included women aged 18-45 (BMI ≥ 35 kg/m²) undergoing laparoscopic bariatric surgery. Serum FSH, LH, estradiol, Progesterone, and AMH levels were measured at baseline, 3, and 6 months postoperatively. Secondary outcomes included menstrual regularity and hormonal correlations with weight loss.

Results: Bariatric surgery resulted in a highly significant reduction in body weight and BMI over the six-month follow-up period (p < 0.001). Significant hormonal shifts were observed, including increased levels of FSH (p < 0.001) and LH (p = 0.001), a decreased LH/FSH ratio (p = 0.005), and marked reductions in estrogen and progesterone concentrations (p < 0.001). While AMH levels remained stable (p = 0.6), menstrual regularity improved significantly from 20% at baseline to 53.3% post-surgery (p = 0.001). Furthermore, the degree of weight loss was significantly and positively correlated with postoperative FSH and LH levels. The interventions were generally well-tolerated, with 82.4% of participants reporting no postoperative complications. No significant differences in the improvement of weight or hormonal profiles were noted between patients with and without PCOS.

Conclusion: Bariatric surgery induces weight loss and restores reproductive hormonal balance in women with obesity by improving HPO axis regulation. Increased FSH and LH levels, resulting from reduced adiposity, might contribute to improved menstrual regularity.

Key points: • Bariatric surgery resulted in a significant and progressive reduction in body weight and BMI over the six-month follow-up period (p < 0.001). • There was a significant postoperative increase in FSH and LH levels. Estrogen and progesterone concentrations demonstrated significant and sustained reductions post-surgery, whereas AMH levels remained stable throughout the study. • Menstrual regularity improved significantly, increasing from 20% of participants at baseline to 53.3% six months after surgery (p = 0.001). • The degree of weight loss was significantly and positively correlated with postoperative FSH and LH levels.