Methods: The study population included infertile couples diagnosed as PCOS in the wife. The women used clomiphene for at least six cycles in order to ovulate after failure to form the dominant follicle, and were then put on letrozole for four cycles. Patients who were unable to form the dominant follicle were enrolled on letrozole and clomiphene combination therapy.

Results: One hundred enrolled patients underwent 257 cycles of a combination of letrozole and clomiphene, in which 213 were able to form the dominant follicle (82.9%) and 44 were unable to do so (17.1%). The number of mature follicles was 2.3±1.1. The mean endometrial thickness in patients on the day of human chorionic gonadotropin administration was 8.17±1.3 mm. The pregnancy rate was 42%.

Conclusion" According to the results of this study, it can be proposed that in PCOS patients resistant to clomiphene and letrozole used as single agents, a combination of the two drugs can be administered before using more aggressive treatment that may have severe complications or surgery. This combination may also be used as a first-line therapy to induce ovulation in severe cases of PCOS in order to save time and expense.

Hajishafiha, Masomeh et al. “Combined letrozole and clomiphene versus letrozole and clomiphene alone in infertile patients with polycystic ovary syndrome.” Drug design, development and therapy vol. 7 1427-31. 3 Dec. 2013, doi:10.2147/DDDT.S50972