Mycoplasmas and in vitro fertilization.

Semen samples taken from 135 patients attending an in vitro fertilization clinic were shown to be colonized, 53 with Ureaplasma urealyticum (39%) and 16 with Mycoplasma hominis (12%). An unidentified mycoplasma species was isolated from the sperm of two patients. M. hominis was recovered from all the washed sperm samples taken from colonized semen, whereas washing the sperm eradicated U. urealyticum from 71% of colonized semen. The presence of mycoplasmas in semen made no significant difference to the sperm count, sperm motility, sperm abnormalities, or fertilization of eggs.