Impact of semen characteristics on the success of intrauterine insemination

Patients: To evaluate the influence of sperm characteristics on the outcome of infertility treatment using intrauterine insemination (IUI). Methods: Retrospective study of 431 infertility couples who underwent 1007 IUI treatment cycles from June 1999 to October 2002. Sperm parameters before and after preparation for IUI were evaluated and correlated with pregnancy outcome. Results: Clinical pregnancy occurred in 12% of cycles and 28% of patients. Initial sperm motility and processed forward progression were independently associated with pregnancy after IUI. The mean number of cycles per patient was 4.3. Although pregnancy rate per cycle did not differ from cycle to cycle, the cumulative pregnancy rate approached plateau after five cycles. Conclusions: Sperm motility is an independent factor influencing IUI-related pregnancy. A forward progression score of 3 to 4 in a processed specimen is necessary for IUI success. The number of IUI attempts per patient should be individualized depending upon the needs of patients.