RESUMEN
OBJECTIVE: To evaluate prognostic factors for pregnancy after intrauterine insemination (IUI). METHODS: A retrospective study was conducted among couples who underwent IUI at Universidade de São Paulo, Brazil, between January 31, 2008, and April 30, 2016. The main outcome was a positive ß human chorionic gonadotropin (ß-hCG) test result after IUI. Univariate analyses were used to determine predictors of pregnancy. Selected numerical variables were categorized to maximize the area under the receiver operating characteristic (ROC) curve. Logistic regression was performed using the backward method. The quality of the model was evaluated using the R2 (Nagelkerke) and Hosmer-Lemeshow tests. RESULTS: Of 355 insemination cycles, 56 (15.8%) resulted in a positive ß-hCG test result. The predictors and cutoff values that maximized the area under the ROC curve were as follows: follicle-stimulating hormone (<7.7 mIU/mL; P<0.001); duration of infertility (<62 menses; P<0.001); number of follicles greater than or equal to 14 mm (>1 follicle; P<0.001); baseline spermatozoa concentration (>52.0 million/mL; P=0.007); total ejaculate (>123.7 million; P=0.003); and grade B motility (>35%; P=0.013). These factors were able to predict 50.4% of the positive test results (R2 ). CONCLUSION: Prognostic factors for pregnancy identified approximately half of all successful outcomes after IUI.