Comparison of the efficacy of letrozole and gonadotropin combination versus gonadotropin alone in intrauterine insemination cycles in patients with unexplained infertility

INTRODUCTION: This study aimed to determine the outcomes of combined treatment of letrozole (LTZ) with recombinant follicle-stimulating hormone (rFSH) in comparison with rFSH alone in intrauterine insemination (IUI) cycles.
METHODS: This study consisted of 86 patients who experienced 106 IUI cycles. Patients were classified into two treatment groups: group I underwent a combination of LTZ plus rFSH, and group II received rFSH alone. Ovulation was triggered with human chorionic gonadotropin (hCG), and IUI performed 36 hours later. The number of follicles ≥18 mm, endometrial thickness, required dose of FSH, duration of ovulation induction (OI), clinical pregnancy rates, multiple pregnancy rates, spontaneous abortion rates, and live birth rates were evaluated.
RESULTS: The total required rFSH dose during the OI was significantly lower in the LTZ-rFSH combination group than the rFSH alone group (401.2±177.1 IU and 770.1±345.8 IU, respectively, p<0.001). The days of stimulation with rFSH were also lower in the LTZ co-treatment group than the rFSH-alone group (5.2±1.3 days and 10.1±3.0 days, respectively, p<0.001). Clinical pregnancy rate was 17.0% in LTZ-rFSH group, and 15.2% in rFSH group (p>0.05).
DISCUSSION AND CONCLUSION: The combined use of LTZ with rFSH resulted in a lower required dose of rFSH, a similar and acceptable endometrial thickness at the day of hCG administration, and comparable pregnancy rate compared with rFSH alone.