The objective of this study was to determine the association between mycotoxins and the quality of spermatozoa in Nigeria. We designed a prospective case-control study involving 136 men diagnosed with reduced sperm count and quality in five infertility clinics in southwest Nigeria and 154 normal fertile controls. Sperm analysis was conducted in accordance with the recommendations of the World Health OrganizationWHO, while Liquid Chromatography–Mass Spectrometry was used to assay three metabolites of mycotoxins (zearalenone, ochratoxin A, and deoxyvinelol) in the urine samples of cases and controls. The data were analysed with descriptive statistics and non-parametric linear regression. The results showed no overall significant difference in levels of these metabolites between the cases and control groups. In contrast, higher levels of zearalenone and ochratoxin A significantly decreased sperm motility in the cases. Similarly, an increase in the level of ochratoxin A decreased sperm morphology in the unadjusted model in the cases. We conclude that exposure to mycotoxins reduces the quality of spermatozoa (motility and morphology) in Nigerian men but may have no effect on sperm count. Efforts to reduce the exposure of men to mycotoxins are important interventions to improve sperm quality and reduce the prevalence of male infertility in the country.

Background: Parabens, which are chemicals used as preservatives in cosmetic and pharmaceutical products, have been reported to be associated with low sperm quality in animal and human models. Despite the high exposure of men to paraben-containing products in Nigeria, there are no known studies that investigate the association of parabens with sperm quality in the country. Objective: To determine the association of urinary levels of metabolites of parabens with sperm count and quality. Design/Setting: A multicenter case–control study among fertile and infertile men in five hospitals in southern Nigeria. A total of 136 men diagnosed with male infertility (cases) were compared with 154 controls with normal fertility. Urinary levels of parabens (ethyl-paraben, methylparaben, propylparaben, and butylparaben) were measured using liquid chromatography mass spectrometry, while semen analysis and hormone assays were carried out using World Health Organization standards and radioimmunoassay, respectively. Data were analyzed with non-parametric statistics and non-parametric linear regression. Results: The results showed high levels of parabens in both cases and controls. However, there was no statistically significant difference in urinary levels of ethyl-paraben, methylparaben, propylparaben, and butylparaben between cases and controls. In contrast, propylparaben had a decreasing association with total motility in both groups, but the effect was only statistically significant in the case of male infertility. The results of the regression analysis showed that a unit increase in propylparaben significantly decreased total motility in the cases (infertile men). Similarly, a unit increase in propylparaben decreased morphology significantly in the unadjusted model for infertile men. Only serum testosterone showed an insignificant correlation with urinary parabens. Conclusion: We conclude that urinary parabens are associated with features of poor sperm quality – motility, morphology, and volume. Measures to reduce exposure of men to agents containing parabens in Nigeria may reduce the prevalence of male infertility in the country.

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.