Do baseline AMH levels in women with polycystic ovary syndrome predict ovulation rate and time to ovulation: a secondary analysis of PCOSAct trial?

Objective: To assess the association of baseline anti-Müllerian hormone (AMH) levels with ovulation, time to ovulation and fertility outcomes in women with polycystic ovary syndrome (PCOS) receiving clomiphene citrate (CC) and compare this with placebo. Design: Secondary analysis of the PCOSAct trial (NCT01573858). Setting: 27 trial centres in mainland China. Population or sample: 1000 infertile women with PCOS receiving either CC or placebo. Methods: Baseline serum AMH was measured and analysed as a continuous and as a categorical variable. Interaction between AMH and CC was tested. Predictive values of AMH for ovulation, time to ovulation and fertility outcomes were assessed. Main outcome measures: Ovulation and time to ovulation. Results: 900 baseline AMH data were available for analysis. There were no significant interactions with ovulation or conception for AMH and CC treatment (P = 0.782 and 0.419, respectively). Women in the upper quartile of AMH >15.88 ng/ml had significant lower ovulation (odds ratio [OR] 0.34, 95% CI 0.20–0.58) and conception rates (OR 0.65, 95% CI 0.42–1.00) compared with women in the lower quartile. Associations of AMH with clinical pregnancy (OR 0.98, 95% CI 0.95–1.01) and live birth (OR 0.98, 95% CI 0.96–1.01) were not significant. Ovulation rate increased until baseline AMH levels ≥7.0 ng/ml in women treated with CC but decreased when AMH increased in women with placebo. When AMH <7.0 ng/ml, an AMH threshold at 4.11 ng/ml predicted ovulation in women receiving CC (area under the curve [AUC] 0.64, 95% CI 0.42–0.86), with a sensitivity of 64% and a specificity of 62%, whereas prediction was poor for AMH ≥7.0 ng/ml (AUC 0.38, 95% CI 0.28–0.47). Median time to ovulation was 35 days in the lower quartile for women with placebo but this was significantly prolonged up to 98 days in the upper quartile. CC significantly shortened the time to ovulation up to 56 days. Conclusions: Among women with PCOS, high baseline AMH levels were associated with a 20.1% lower chance of ovulation with a 63-day longer time to ovulation. AMH can predict ovulation only when the baseline AMH level was <7.0 ng/ml in women with PCOS undergoing ovulation induction with CC. Tweetable abstract: Ovulation rate increased until baseline AMH levels ≥7.0 ng/ml in women treated with CC; a successful ovulation and time to ovulation was highly associated with baseline AMH level in these women.