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 follicule­stimulating hor­ mone levels. A statistical significance in LET versus CC­stimulated 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 CC­stimulated group (15.0% vs 11.8%). Clinical PRs after timed IUI were also significantly higher in the LET versus CC­stimulated 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: Unex­ plained infertility patients who underwent LET stimu­ lation with IC were found to have better pregnancy out­ comes as compared to those who underwent timed IC or IUI with CC stimulation. (J Reprod Med 2016;61:000– 000)