Leucospermia and the fertilizing capacity of spermatozoa.

Ejaculates obtained from men attending an in vitro fertilization (IVF) program were analyzed to determine the effect of the presence of leucocytes in semen on the ability of sperm in that semen to fertilize oocytes. The mean (+/- S.E.) concentration of leucocytes in 103 ejaculates was 0.62 X 10(6)/ml (+/- 0.09) with a range of 0.1 X 10(6) or less per ml to 7.0 X 10(6)/ml. The leucocyte concentration demonstrated a significant (p less than 0.05) but inverse relationship with the fertilizing capacity of spermatozoa. Though not statistically significant, the leucocyte concentration also demonstrated an inverse relationship to sperm motility and normal morphology. These results suggest that the presence of leucocytes in an ejaculate cannot be used as the sole indicator of the fertilizing capacity of spermatozoa in that ejaculate.