Ureaplasma urealyticum and infertility: the effect of different antibiotic regimens on the semen quality.

Objectives criteria of semen quality were evaluated in 243 men treated for Ureaplasma urealyticum genital tract infection with 1 of 4 different antibiotic regimens. Significant improvement was observed in motility, quantity, quality, and percentages of oval and small forms. Doxycycline, whether used for 2 or 4 weeks, at a dosage of 100 mg, twice daily resulted in the same cure rate (79 and 81 per cent, respectively). Tetracycline regimens of 500 mg. 3 times daily for 2 or 4 weeks had significantly inferior cure rates (17 and 55 per cent, respectively). These findings suggest that antibiotic therapy could be valuable in improving semen quality when Ureaplasma is isolated, and that followup culture for the organism should decide the endpoint in therapy, since resistant strains for doxycycline and tetracycline are emerging.