Prediction of pregnancy by intrauterine insemination using CASA estimates and strict criteria in patients with male factor infertility

Abstract

This study was performed to predict pregnancy by intrauterine insemination (IUI) using computer-aided sperm analysis (CASA) estimates and strict criteria in patients with male factor infertility. IUI was performed in 682 cycles on 160 male factor infertile patients. Semen examinations were carried out by CASA and strict criteria before and after sperm preparation using continuous-step density gradient centrifugation. Receiver operating characteristics (ROC) curves were constructed for assessment of the effectiveness of each individual parameter in predicting pregnancy by IUI. A clinically acceptable threshold was calculated when sensitivity plus specificity were maximum. The average cycle of IUI performed was 4.3 +/- 2.4. Pregnancy rate per cycle and per patient were 7.2% (49/682) and 28.1% (45/160), respectively. Using ROC curve, it was shown that normal sperm morphology assessed by the strict criteria before sperm separation and five parameters after sperm separation including rapid, progressive motility, average path velocity (VAP), curvilinear velocity (VCL), and straight line velocity (VSL) were able to predict pregnancy by IUI. Correlation between sperm parameters and pregnancy outcome was examined by the logistic regression model. In a multivariate analysis normal morphology before sperm separation >or=15.5% [odds ratio (OR) = 2.2, p = 0.02], rapid after sperm separation >or=25.5% [OR = 3.9, p = 0.029], and VCL after sperm separation >or=102.65 microm/sec [OR = 3.2, p = 0.002] were the parameters of predictive value for pregnancy outcome. Adjustment of the model for female age, female infertility factors, and the methods of ovulation induction did not change this finding, and the final model still had the same covariates. Pregnancy rates per cycle according to the number (0, 1, 2 and 3) of variables satisfied with the three parameters were 0% (0/110), 1.6% (3/183), 9.7% (21/217) and 15.1% (23/151), respectively. Three semen parameters including normal morphology before sperm separation, rapid and VCL after sperm separation were identified as predictors of pregnancy by IUI. These variables would be helpful when counselling patients before they make the decision to proceed with in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI)-ET.