Anti‐Müllerian hormone reduction after ovarian cyst surgery is dependent on the histological cyst type and preoperative anti‐Müllerian hormone levels

OBJECTIVE: To investigate changes in serum anti-Müllerian hormone (AMH) concentrations following ovarian cyst surgery, and predictors of these changes. DESIGN: Prospective cohort study with follow up at 3 and 6 months. SETTING: University hospital. POPULATION: Women of reproductive age scheduled for ovarian cyst surgery. METHODS: Women were recruited between March 2011 and March 2012 (n = 75). Serum AMH concentrations were measured preoperatively and at 3 and 6 months postoperatively. MAIN OUTCOME MEASURES: Changes in AMH after surgery and predictors for these changes. RESULTS: After surgery, median AMH levels decreased significantly from 2.7 μg/L (0.2-16.9) to 1.6 μg/L (0.2-9.9) at 3 months and were still low, 1.6 μg/L (0.2-8.3) at 6 months (both p < 0.001). In patients with unilateral cysts, a significant and more rapid AMH decrease was seen after enucleation of endometriomas (n = 19) vs. dermoid cysts (n = 22) (p = 0.010). The reduction was long-lasting at 6 months. In a multivariate regression analysis, a higher baseline AMH concentration was predictive of AMH reduction at 3 [odds ratio (OR) 1.9, 95% CI 1.1-3.1] and 6 months postoperatively (OR 2.5, 95% CI 1.2-5.2). Women with normal or elevated baseline AMH presented with a significant reduction of -23% and -43% at 3 and 6 months, respectively, whereas women with low or very low AMH had minimal or no changes over time. Patient's age, cyst size, duration of surgery or intraoperative bleeding were not predictive of a postoperative AMH decrease. CONCLUSIONS: Reduction of AMH was of greater magnitude and longer duration after enucleation of endometriomas and in women with normal and high preoperative AMH levels.