Comparision of Letrozole with Timed Intercourse Versus Clomiphene Citrate with Intrauterine Insemination in Patients with Unexplained Infertility.

OBJECTIVE: To evaluate outcomes of patients with unexplained infertility who underwent letrozole (LET)- stimulated controlled ovarian stimulation (COS) with timed sexual intercourse (IC) as compared to patients treated with clomiphene citrate (CC) and intrauterine insemination (IUI). STUDY DESIGN: A non- randomized, retrospective study where unexplained in- fertility patients (n=7,764). underwent a COS cycle with both LET and timed IC or with CC and IUI from January 2010-June 2014. One group consisted of patients who completed a COS cycle with LET and were instructed to have sexual IC. The other included patients were treated with CC and underwent IUI. Pregnancy rates (PRs) were compared between groups. RESULTS: No statistical difference was observed in each group's age or serum follicule-stimulating hor- mone levels. A statistical significance in LET versus CC-stimulated groups was observed for mean endome- trial thickness (8.3 ± 1.7 vs. 7.9 ± 1.8 mm) and follicular response (2.0 ± 1.0 vs. 2.3 ± 1.3), respectively. Clinical PRs after timed IC were significantly higher in the LET versus CC-stimulated group (15.0% vs 11.8%). Clinical PRs after timed IUI were also significantly higher in the LET versus CC-stimulated group (12.3% vs. 11.5%). Moreover, clinical PRs in LET with IC were significant- ly higher than CC with IUI (15.0% vs. 11.5%). CONCLUSION: Unexplained infertility patients who underwent LET stimulation with IC werefound to have better pregnancy out- comes as compared to those who underwent timed IC.or IUI with CC stimulation.