The relationship of pyospermia and seminal fluid bacteriology to sperm function as reflected in the sperm penetration assay.

The relationship of the parameters of seminal fluid analysis (SFA) and seminal fluid leukocyte concentration to the in vitro sperm penetration assay (SPA) was studied in 217 men from infertile couples. Significant positive correlations were found between the SPA and sperm count, sperm motility, and morphologically normal sperm. The total number of leukocytes per milliliter, the number of polymorphonuclear leukocytes per milliliter (PMN), and the number of lymphocytes per milliliter were negatively correlated with the results of the SPA. The strongest correlation with an abnormal SPA (less than 11% of eggs penetrated) was the presence of greater than or equal to 1 PMN/100 sperm (8.17 increased relative risk of an abnormal SPA). The most important predictor variables of the percent penetration of the sperm penetration assay were total numbers of leukocytes per milliliter, sperm count, and sperm motility. Microbiologic studies of semen were not correlated with SPA results or number of leukocytes in the semen.