Observation of the Effect of Letrozole in Ovulation Induction in Infertile Women with Polycystic Ovary Syndrome

Objective To investigate the effect of letrozole as a drug for ovulation induction in infertile women with polycystic ovary syndrome(PCOS) and influence on reproductive hormones. Methods A total of 43 PCOS infertile women were timed intercourse from January 1st 2007 to November 30st 2007. Ovulation was induced using 2.5mg/day letrozole administered daily from day 3 to 7 of the cycle or 50mg/day CC from day 5 to 9 of the cycle. From day 10,Ultrasound scan was performed to monitor follicle development.Blood sample was drawn on day 8 and day of HCG administration to test LH,E2 and T. When the diameter of the biggest follicle reached ≥18mm,10 000IU HCG was injected to trigger ovulation. To observe ovulation rate,pregnancy rate,the thickness of endometrium and influence on reproductive hormones. Results In letrozole group the ovulation rate was significantly higher than in CC group(P0.01).There was no difference in pregnancy rate per cycle between both groups(P0.05).B oth the numbers of dominant follicle and mature follicle were significantly less in the former group than those in the latter group(P0.05). The thickness of endometrium on the day of HCG administration in the letrozole group was much thicker than that in CC one(P0.01). The level of E2 was much lower in the letrozole group(P0.01) on the day 8 and day of HCG administration.While testosterone in serum was significantly higher than that in CC group(P0.05). Although both group had the same levels of LH on day 8,the letrozole group had much higher LH on day of HCG than CC one(P0.01). Conclusion letrozole can attain good ovulation rate in PCOS infertile women.There was no influence in growth of endometrium.