Comparing Naltrexone and Metformin Pretreatment for Inducing Ovulation in Patients With Polycystic Ovary Syndrome in Intrauterine Insemination Cycles

Polycystic ovary syndrome (PCOS) is a common endocrine disorder among women. Hyperinsulinemia and insulin resistance are normally observed in PCOS patients and metformin is used to treat this disease. The evidence indicates that the opioid system plays a role in the pathogenesis of the PCOS. Based on the above-mentioned explanation, the present study evaluated the role of opioid antagonist (naltrexone) in PCOS-induced infertility compared to metformin.

Totally, 120 patients afflicted with PCOS were assigned to three groups based on Rotterdam diagnostic criteria, with a body mass index (BMI) of 25-30 kg/m2. The first group received naltrexone (50 mg/d) for 8 weeks. In addition, the second group were injected with metformin 1000 and then 1500 mg/d for the first and seventh weeks, respectively. Finally, the third group entered the intrauterine insemination (IUI) without prior therapeutic treatment. Then, the groups were compared in terms of the amount of estradiol produced per day of human chorionic gonadotropin injection and the total amount of gonadotropin needed, the number and size of the adult follicles, the number of days of taking the drug, and incidence of pregnancy-induced abo

Based on the results, the mean of infertility duration was not significant among the three groups (P = 0.782). Further, the mean fasting insulin level between the metformin and control groups represented a significant difference (P = 0.045). The average number of days to trigger patients in the 3 groups was not significant (P = 0.346). Although the average number of follicles between metformin and naltrexone groups was not significant, it was higher in the naltrexone group. Finally, the average BMI of the naltrexone group after the treatment was lower compared to before treatment (P ≤ 0.001).

In general, the number of receiving days and the dose of the drug in the naltrexone group was lower compared to the metformin group. Furthermore, the number of mature follicles in both ovaries and the serum estradiol level in the naltrexone group was higher compared to the metformin group.