Spermatozoa selection in discontinuous Percoll gradients for use in artificial insemination.

In a preliminary study of the ejaculate of 93 men, changes in motility and hypo-osmotic swelling before and after sperm separation by discontinuous Percoll gradients were evaluated. Both parameters improved significantly (P less than 0.01) in Percoll-separated spermatozoa. In a second stage, 99 couples underwent intrauterine insemination of separated semen by Percoll gradients. The population had infertility for a mean of 5.6 years. In a 1-year period, a total of 344 intrauterine insemination cycles were completed. Failure was considered when conception did not occur within four treatment cycles. The mean number of cycles per successful couple before pregnancy was 1.52. An overall 21% pregnancy rate was achieved (16% for oligoasthenospermia and 24% for asthenospermia). Sperm separation in Percoll gradients is a useful technique for intrauterine insemination in some cases of male subfertility.