Received June 28, 2020
Accepted November 14, 2020

Objective: The aim of the present study is to assess the success of controlled ovarian stimulation in intrauterine insemination cycles stimulated by recombinant-FSH and Clomiphene citrate for either mono- or bi-follicular development. Methods: A total of 870 infertile patients treated with controlled ovarian stimulation in intrauterine insemination cycles at a university-based infertility clinic between January 2012 and December 2017 were evaluated. Cycles stimulated by clomiphene citrate and recombinant-FSH are compared in two set-ups; mono- and bi-follicular development. The main outcome measure was clinical pregnancy rate per cycle. Results: The demographic and cycle parameters were similar between the groups except endometrial thickness on the day of hCG administration which was higher in the recombinant-FSH group than the clomiphene citrate group. The overall clinical pregnancy rates in clomiphene citrate and recombinant-FSH groups were 9.8% and 10.3%, respectively(P=0.940). Regarding the entire cohort, the clinical pregnancy were significantly higher in case of bi-follicular development when compared to mono-follicular development (16.8% vs. 10.2%, respectively;P=0.009). Conclusion: Clomiphene citrate and recombinant-FSH have similar success in terms of clinical pregnancy, in either mono-follicular development or bi-follicular development. Clomiphene citrate and recombinant-FSH cycles result in comparable rates of bi-follicular development which significantly increases clinical pregnancy rate. Clomiphene citrate and recombinant-FSH have similar success in terms of clinical pregnancy rate, in either mono-follicular development or bi-follicular development.