N-Acetyl cysteine and clomiphene citrate for induction of ovulation in polycystic ovary syndrome: a cross-over trial

OBJECTIVE: To compare clomiphene citrate plus N-acetyl cysteine versus clomiphene citrate for inducing ovulation in patients with polycystic ovary syndrome. DESIGN: Prospective cross-over trial. SETTING: University teaching hospital and a private practice setting. PATIENTS: Five hundred and seventy-three patients were treated with clomiphene citrate for one menstrual cycle among which 470 patients were treated with clomiphene citrate plus N-acetyl cysteine for another cycle. All women suffered from polycystic ovary syndrome. INTERVENTIONS: Patients had clomiphene citrate 50-mg tablets twice daily alone or with N-acetyl cysteine 1,200 mg/day orally for 5 days starting on day 3 of the menstrual cycle. OUTCOME MEASURES: Primary outcomes were number of mature follicles, serum E2, serum progesterone, and endometrial thickness. Secondary outcome was the occurrence of pregnancy. RESULTS: Ovulation rate improved significantly after the addition of N-acetyl cysteine (17.9% versus 52.1%). Although the number of mature follicles was more in the N-acetyl cysteine group (2.1+/-0.88 versus 3.2+/-0.93), the difference was not statistically significant. The mean E2 levels (pg/ml) at the time of human chorionic gonadotropine injection, serum progesterone levels (ng/ml) on days 21-23 of the cycle, and the endometrial thickness were significantly improved in the N-acetyl cysteine group. The overall pregnancy rate was 11.5% in the N-acetyl cysteine group. Insulin resistance occurred in 260 patients (55.4%). There was no significant difference between the insulin resistance group (n = 260) and non-insulin resistance group (n = 210) as regards ovulation rate, number of follicles, serum E2 (pg/ml), serum progesterone (ng/ml), endometrial thickness (mm), or pregnancy rate. CONCLUSION: N-Acetyl cysteine is proved effective in inducing or augmenting ovulation in polycystic ovary patients.