Effect of gonadotropins and endometrial thickness on pregnancy outcome in patients with unexplained infertility or polycystic ovarian syndrome undergoing intrauterine insemination

OBJECTIVE: The purpose of this study was to investigate the effect of gonadotropin dose and endometrial thickness (EMT) on pregnancy outcome in patients undergoing intrauterine insemination (IUI). METHODS: We retrospectively analyzed data from 361 patients with unexplained infertility or polycystic ovarian syndrome (PCOS) who underwent 930 IUI cycles treated with gonadotropins. Then, we measured the effects of gonadotropins and EMT on the clinical pregnancy rate. Finally, we assessed the association of various doses of gonadotropins on EMT. RESULTS: The dose of gonadotropins given and thickness of the endometrium were higher in the pregnancy group than in the nonpregnancy group (636.0 vs. 600.0 IU for gonadotropin dose; 9.15 vs. 8.70 mm for EMT). Clinical pregnancy rates were significantly improved by increasing the dose of gonadotropins (9.1%, <450 IU; 16.2%, 450–599 IU; 18.6%, 600–749 IU, and 17.3%, ≥750 IU), or by increased EMT (0%, <5.0 mm; 12.2%, 5.0–6.9 mm; 15.5%, 7.0–14.0 mm; and 33.3%, >14.0 mm). CONCLUSION: Increasing the dose of gonadotropins to stimulate one follicle to develop may benefit endometrial proliferation and improve IUI outcomes.