Round cells and sperm fertilizing capacity: the presence of immature germ cells but not seminal leukocytes are associated with reduced success of in vitro fertilization.

Fifty semen samples produced for IVF by patients diagnosed as having unexplained infertility were screened for leukocytes, leukocyte subsets, and immature germ cells using a mAB-based staining procedure. Nonfertilizing ejaculates were found to contain significantly larger numbers of immature germ cells, although no significant differences in leukocyte content were observed between groups. Neither sperm density or progressive motility were significantly different between fertilizing and nonfertilizing groups. We conclude that seminal leukocytes have little if any influence on the fertilizing capacity of the spermatozoa in patients undergoing IVF for unexplained infertility, but the presence of large numbers of germinal elements is associated with reduced fertilizing capacity and may be indicative of an immature sperm population.