Effects of letrozole alone or letrozole in combination with low-dose intramuscular injection of human menopausal gonadotropin on ovulation and pregnancy of 150 patients with polycystic ovary syndrome

Abstract

Background: Objective of the study was 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: The study comprised of 150 couples who were randomly divided into two groups of 75 each. Group “A” received letrozole (LE) in a dose of 2.5 mg to 5mg /d. LE was started orally starting on 3rd to 5th day of menstrual cycle for 5 consecutive days. Group “B” received letrozole in a dose of 2.5 to 5 mg/day starting on the 3rd to 5th day of menstrual cycle for 5 consecutive days. Starting from the day of oral administration of letrozole, 75 IU HMG was injected intramuscularly on alternate days for 5 consecutive doses. The ovulation induction parameters and pregnancy outcomes were observed.Results: The Group A (LE group) had the most completed cycle (310 cycles), 157 (52.3%) of which had ovulation. The Group B (LE+HMG) group completed the fewest cycles (258 cycles), with 168 (65.1%) of them ovulating. This difference was statistically significant (P<0.05). On HCG injection day, both the endometrial thickness (11.5±1.2) and number of mature follicles (2.1±1.3) of the Group B were significantly higher than those of Group A (P<0.001), but the follicle diameters were similar (P>0.05) The pregnancy rate of the Group B was 54.7%, which was significantly higher than that of the Group A (29.3 %) (P<0.05) The average medication cycle of the Group B group was significantly shorter than that of the Group A (P<0.05).Conclusions: 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.