Effects of letrozole in combination with low-dose intramuscular injection of human menopausal gonadotropin on ovulation and pregnancy of 156 patients with polycystic ovary syndrome

OBJECTIVE To explore the effects of letrozole (LE) in combination with low-dose intramuscular injection of human menopausal gonadotropin (HMG) on the ovulation induction and pregnancy of patients with polycystic ovary syndrome (PCOS). METHODS A total of 156 patients with PCOS infertility were randomly divided into an LE group, a clomiphene citrate (CC) group and an LE + HMG group (n= 52). LE and CC were orally taken according to the prescribed dosage on the 3rd-5th days of menstruation respectively, and 75 IU HMG was given through intramuscular injection. The ovulation induction parameters and pregnancy outcomes were observed. RESULTS The number of ovulation cycle of LE + HMG group was significantly higher than that of LE group (χ2=8.451, P<0.001). After injection of human chorionic gonadotropin, both endometrial thickness and number of mature follicles of LE + HMG group were significantly higher than those of other two groups (P<0.001), and the daily estradiol (E2) level was also higher (q=4.531, P<0.05). The pregnancy rate of LE + HMG group was 55.7%, which exceeded those of other two groups (compared to LE group, χ2=4.012, P<0.05). In LE + HMG group, the average medication cycle of clinically pregnant patients was (2.9 ± 0.3) weeks, which was significantly shorter than those of CC and LE groups (F=17.241, P<0.001). CONCLUSION The regimen using LE in combination with low-dose intramuscular injection of HMG has satisfactory therapeutic effects on ovulation induction, short medication cycle and high clinical pregnancy rate, which is promising for treating patients with PCOS infertility.