Correlation of semen transferrin concentration and sperm fertilizing capacity.

To determine whether a correlation exists between semen transferrin and sperm fertilizing capacity, transferrin concentration was determined in the semen of 52 male patients referred for the hamster ova penetration test (group 1) and in 17 men participating in the human in vitro fertilization program (group 2). In both groups 1 and 2 seminal transferrin levels were also compared to semen volume, sperm density, and motility. Serum follicle-stimulating hormone and luteinizing hormone concentrations that were determined in 34 individuals (24 in group 1, 10 in group 2) showed no correlation with seminal transferrin levels. In conclusion, low seminal transferrin levels correlated with low sperm density and with poor fertilizing ability of human oocytes in vitro.