Objective To compare the effects of letrozole (LE), clomiphene citrate (CC) and human menopausal gonadotropin (HMG) on ovarian stimulation in the patients with polycystic ovary syndrome (PCOS), and to investigate the advantage of LE. Methods One hundred and fifty patients with PCOS were randomly divided into CC group, LE group, CC+HMG group, LE+HMG group and HMG group. We compared the numbers of mature follicle (diameters≥14mm) on the human chorionic gonadotrophin (HCG) injection day, cases with more than three mature follicles, ovulation rate, incidence rate of luteinized unruptured folliclesyndrome (LUFS), endometrial thickness on the HCG injection day, amount of HMG, duration of induced ovulation, and the pregnancy rate of patients in these different groups. Results The amount of mature follicle and the cases of patients with more than three mature follicles on the HCG injection day were both significantly less in LE and LE+HMG groups than those in other groups (P<0.05). The lower ovulation rate and higher incidence rate of LUFS were shown in CC group, which had significant differences with other groups (P<0.01). The endometrial thicknesses on the HCG injection day were significantly higher in LE, LE+HMG, and HMG groups, compared with other groups (P<0.05). The amount of HMG was significantly lower in LE+HMG group than CC+HMG and HMG groups (P<0.05). It showed that the duration of induced ovulation in HMG group was longer (P<0.05), and the pregnancy rates were significantly lower in CC group(P<0.05). Conclsion Compared with CC and HMG treatment, LE showed higher ovulation rate, lower incidence rate of LUFS, higher rate of one follicle, higher endometrial thickness on the HCG injection day, higher pregnancy rate, the shorter duration of induced ovulation, and less cost more in ovulation induction of PCOS.
