Induction of Ovulation with Clomiphene Citrate Combined with Bromocriptine in Polycystic Ovary Syndrome Patients with Infertility: A Prospective, Randomized, and Controlled Clinical Trial

Abstract

Background: To investigate the therapeutic effects of bromocriptine (BCT) combined with clomiphene citrate (CC) in the induction of ovulation in polycystic ovary syndrome (PCOS) patients with infertility. Methods: A prospective, randomized, and controlled clinical trial was performed on 100 PCOS patients with infertility. Patients were randomly divided into two groups (n = 50), patients in control group were treated with 50 mg CC from day 3 to day 7 of the menstrual cycle, and those in observation group (CC + BCT) were given 50 mg of CC from day 3 to day 7 of the menstrual cycle along with 2.5 mg of BCT daily for the full cycle. Patients in both groups were treated for one cycle. Blood was extracted from patients on day 3 of the menstrual cycle, the day of human chorionic gonadotrophin (hCG) injection, and day 7 after hCG injection to measure serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), estradiol (E2), total testosterone (T) and progestin (P). Vaginal ultrasound was used to determine the thickness of endometrium and follicle size and count. Results: There was no significant difference in basal hormone levels between two groups. The success rate of ovulation induction in control group and observation group was 72.0% and 75.4%, respectively, no significant difference was found between two groups (P > 0.05). The ongoing pregnancy rate (18.4%) in observation group was significantly higher than that in control group (8.0%). On the day of hCG injection, no significant differences in the levels of FSH, E2, and P were found between two groups, while LH was lower, and levels of PRL and T were significantly lower in observation group than those in control group (all P = 0.00). On day 7 after hCG injection, no significant differences in the levels of E2 and P were found between two groups, while PRL level was significantly lower in observation group than that in control group, and the endometrial thickness in observation group (10.20 ± 1.92 mm) was significantly higher than that in control group (9.22 ± 1.88 mm) (P = 0.01). Conclusions: Compared with the use of CC alone, BCT combined with CC can increase the success rate of ovulation induction-assisted pregnancy in PCOS patients, decrease the levels of PRL, LH, and T and increase the endometrial thickness in implantation window. Those data suggest that dopamine agonist BCT may reduce the pituitary hormone and androgen levels, reduce endometrial vascular resistance, and increase endometrial blood supply to improve the infertility outcomes of PCOS patients with infertility.