Ureaplasma parvum impaired semen quality improves after doxycycline treatment in selected patients: a cohort study

Infections of the urogenital tract are recognized as potential contributors to male subfertility or infertility. Ureaplasma parvum is frequently detected in semen samples, yet its specific impact on semen quality and the potential benefit of antibiotic treatment remain uncertain.

In a retrospective cohort of 3,464 semen samples collected for fertility evaluation, Ureaplasma parvum was identified in 12.4% of cases using a multiplex PCR assay. Semen volume was significantly lower in infected individuals compared to uninfected controls. However, no significant differences were observed in sperm concentration, motility, morphology, or inflammatory markers. Among 124 men with documented pathogen eradication and follow-up semen analysis, doxycycline treatment led to a significant increase in sperm concentration (4.01 ± 4.69 to 9.20 ± 15.63 million/ml, p = 0.01) and motility (18.97 ± 16.04% to 29.66 ± 22.18%, p = 0.002). Peroxidase-positive leukocytes declined (1.84 ± 0.74 to 0.68 ± 0.79 million/ml, p = 0.005). In contrast, no significant changes were observed in men with normal baseline semen parameters.

The mere detection of Ureaplasma parvum does not appear to compromise semen quality and may not warrant routine antibiotic treatment. Nevertheless, in Ureaplasma parvum-positive patients with abnormal semen parameters and elevated inflammatory markers, targeted antibiotic therapy may improve sperm quality. These findings support a selective treatment strategy, emphasizing clinical context and inflammatory status rather than routine screening or treatment of all infected individuals.