Letrozole Combined with HMG for Induces Ovulation in Women with Polycystic Ovarian Syndrome

Objective To evaluate the clinical effect of letrozole(LE)with HMG or clomiphene citrate(CC)with HMG in treatment of polycystic ovarian syndrome(PCOS).Methods One hundred and twenty-six patients with PCOS were divided into 2 groups treated with letrozole(70 cycles)or CC(82 cycles).Letrozole 5 mg was given daily d 3-7 of menses and CC 100 mg was given daily d5-9 of menses.Patients were monitorized with transvaginal ultrasonography and combined with HMG if needed.When the dominant follicle diameter reached 18 mm,HCG(5 000 U,IM)was given to trigger ovulation.Levels of serum E2,LH,T,P were detected on the day of HCG administration and E2,P on more than 7 days after follicular rupture.The primary endpoints were the number of follicles,endometrial thickness,pregnancy rate and miscarriage rate.Results No significant difference was found between LE group and CC group for endometrial thickness measured on the day of HCG,the duration to reach a dominant follicle and the total dose of HMG.The number of follicles ≥14 mm were significantly less in the LE group,but no significant differences in the ≥18 mm follicles.Levels of serum E2,P/E2 were more lower in LE group,but similar for LH,T,P.The rates of pregnancy,twin gestation,ectopic pregnancy and OHSS were almost consistent in 2 groups.Moreover,withdrawal rate as inefficacy was significantly lower in the LE group.Conclusion LE might be an alternative method in PCOS to induce ovulation,especially for patients no responsing to CC,or with OHSS or thin endometrium.