Background: The purpose of the present study was to identify the postprepared sperm parameters affecting the outcome of intrauterine insemination and to find out whether the volume of insemination specimen was a determinant factor in the rate of successful conception.
Materials and methods: A retrospective study including 306 couples was designed. The patients were inseminated with either 1.0 or 0.5 ml of prepared specimens. The pregnancy rates were compared using the chi-square test. Logistic regression was chosen for multivariant analysis of the parameters.
Results: The only parameter significantly affecting the success rate was the postprepared sperm motility (p = 0.033). The pregnancy rate was 27.91% in cases with > or = 95% sperm motility. Only two patients with less than 75% sperm motility conceived. The pregnancy rates in cases with 0.5 ml and 1.0 ml inseminations were 12.12% and 16.13%, respectively. This difference was statistically insignificant (p = 0.427).
Conclusion: The postprepared sperm motility was the only parameter predicting the successful rate of intrauterine insemination. Seventy-five percent sperm motility can be used as a cut-off value for selecting patients. The volume of insemination specimen did not influence the outcome. Insemination with 1 ml of fluid was just as effective as insemination with 0.5 ml.