Received November 09, 2017
Accepted December 21, 2018

Objective: This study aimed to identify which parameters positively affect the clinical pregnancy rates of IUI cycles and find which couples should opt for IUI. Methods: This retrospective observational study included 261 patients submitted to 381 IUI cycles with fresh or cryopreserved partner semen (IU-H) from January 2012 to February 2017 in a private center in Curitiba-PR, Brazil. Results: Idiopathic infertility was the most frequent finding (35.9%). Patients younger than 40 years accounted for 87.9% of the IUI cycles (n=335) and 16.1% of the clinical pregnancies (n=54). The pregnancy rate was three times higher in patients with an endometrium thickness ≥8 mm compared to patients with endometrium thickness <8mm. Sperm motility >55% was linked to higher pregnancy rates (p=0.002). Concerning gonadotropins, 159 (48.4%) took rFSH, 127 (38.7%) hMG, and 42 (12.8%) uFSH, with pregnancy rates of 21.3%, 10.4% and 10.5%, respectively. Conclusion: Patients under 40 years of age with endometrium thickness ≥8 mm, sperm motility >55%, and on rFSH had significantly higher pregnancy rates (p<0.05).