Association Between Antibiotic Exposure and the Risk of Male Infertility: A Case-Control Study.

Irregular use of antibiotics is widespread in Nigeria, which has been reported to be associated with the prevalence of antibiotic resistance. As antibiotics have been reported to be associated with declining male infertility in animal models, we investigated the association between exposure to antibiotics and sperm quality. The study was a prospective case-control study involving 136 infertile men and 154 fertile men recruited from five hospitals in southern Nigeria. Semen analysis was carried out, while Liquid Chromatography Mass Spectrometry was used to assay for various antibiotics in urinary samples. Three antibiotics showed an independent association with sperm quality in the regression analysis. Urinary ampicillin was associated with more than a 3 mL decline in sperm count in the cases, with no significant effects shown in the control group. Similarly, a significant association of urinary chloramphenicol with sperm motility and sperm morphology was shown in cases of infertility. In contrast, an independent association of urinary tetracycline with increased sperm motility in men with infertility was found, but no significant association was shown in fertile men. We conclude that urinary antibiotics-ampicillin, tetracycline, and chloramphenicol-may be associated with varying sperm characteristics and sperm quality in Nigerian men.