Use of Letrozole versus clomiphene-estradiol for treating infertile women with unexplained infertility not responding well to clomiphene alone, comparative study

Background Clomiphene Citrate (CC) considered as first line treatment option for superovulation in patient with unexplained infertility. However, there is discrepancy between ovulation and conception rates. Objectives Compare the effect of Clomiphene citrate plus Estradiol Valerate with Letrozole on endometrial thickness, pregnancy and abortion rate in women with unexplained infertility. Design This was a randomized double blind study. Setting Zagazig University hospitals and a private practice setting. Patients &methods The study included 172 women unexplained infertility with improper endometrial response to CC in spite of good follicular response. They were randomly divided into two groups: Group A received 100 mg CC from day 3 to day 7 of menstruation and 4 mg Estradiol Valerate on the 8th day of menstruation until 14th day, Group B treated by 5 mg Letrozole from day 3 to 7 of menstruation. Main Outcome Measure(s) Endometrial thickness, pregnancy and miscarriage rates. Result(s) There was a statistically significant difference in endometrial thickness between the two groups, (p value < 0.00) as, the mean of endometrial thickness/was 8.28 ± 1.7in group A (cc + E2) and 9.2 ± 1.8 in group B (Letrozole) respectively. Pregnancy rate was higher in Letrozole (group B) compared to CC (group A) (16.2% & 12.7%) respectively without statistically significant difference. Conclusion(s) Letrozole has good effect on endometrial thickness more than Clomid or Clomid plus estradiol when used in women with unexplained infertility with statistically significant difference, but there was no significant difference regarding pregnancy and abortion rate with slight increase toward Letrozole.