Ureaplasma urealyticum and human infertility: the effect of antibiotic therapy on semen quality.

Semen characteristics were evaluated in 64 men visiting our infertility clinic before and after the eradication of genital infection with Ureaplasma urealyticum. Semen quality was also analyzed in 9 men who were unsuccessfully treated for genital Ureaplasma infection, 11 men who had negative cultures and received no treatment, and 11 men who had negative cultures but received empirical antibiotic therapy. A significant improvement in spermatozoal motility (both the speed of forward progession and the percentage of motile cells) was found in the group that was successfully treated for Ureaplasma infection. Improvements were not demonstrated in any of the other patient groups. A correlation was found between improved motility and a decrease in certain abnormal features of seminal cytology that appear to be associated with Ureaplasma genital infection.