Prediction of an ongoing pregnancy after intrauterine insemination

Objective: To develop a prognostic model for the outcome of IUI. Design: Retrospective cohort study. Setting: Four fertility centers in The Netherlands. Patient(s): Couples of whom the female partners had a regular cycle and who had been treated with IUI. Intervention(s): Intrauterine insemination with and without ovarian hyperstimulation. Main Outcome Measure(s): Ongoing pregnancy. Result(s): Overall, 3,371 couples were included who underwent 14,968 cycles. There were 1,229 (8.2%) pregnancies, of which 1,000 (6.7%) pregnancies were ongoing. Logistic regression analysis demonstrated that increasing maternal age, longer duration of subfertility, presence of male factor subfertility, one-sided tubal pathology, endometriosis, uterine anomalies, and an increasing number of cycles were unfavorable predictors for an ongoing pregnancy. Cervical factor and the use of ovarian hyperstimulation were favorable predictors. The area under the receiver operating characteristic curve was 0.59. When couples were divided into four categories based on prognosis, the difference between the predicted and observed chance, that is, the calibration, was less than 0.5% in each of the four groups. Conclusion(s): Although our model had a relatively poor discriminative capacity, data on calibration showed that the selected prognostic factors allow distinction between couples with a poor prognosis and couples with a good prognosis. After external validation, this model could be of use in patient counseling and clinical decision making. (C) 2004 by American Society for Reproductive Medicine.