Concerns about the worldwide decline in semen quality over the past 50 years are increasing. Western countries have shown a decline in semen quality. However, in non-Western countries studies are sparse. We investigated trends in semen parameters between 1996 and 2007 in the Sfax area of southern Tunisia in a sample of 2940 men in infertile relationships. Age at semen collection, duration of sexual abstinence, volume of seminal fluid, the sperm count, percentages of motile and morphologically normal spermatozoa, and semen leukocyte concentration were determined. Linear regression was used to examine trends over time in sperm count, sperm motility, normal morphology, and semen leukocyte concentration. Mean age and semen volume did not change between 1996 and 2007. Data adjusted for age and abstinence showed a decreasing trend in sperm count and percentage of normal morphology over the last 12 years (R 2 5 0.71, P 5 .0004, and R 2 5 0.87, P , .0001, respectively). There was no significant change in sperm motility. However, semen leukocyte concentration increased significantly over time (R 2 5 0.38, P 5 .03). These results coincide with the high prevalence of genital infectious diseases in the Sfax area, suggesting that infection may be a potential contributing factor in semen quality decline.

The effect of the female genital tract on sperm is not well known. To investigate the effect of cervical mucus on the lipid content of human sperm, we co-incubated sperm and mucus samples in vitro such that the sperm were able to swim in and out of the mucus samples. High performance liquid chromatography and UV detection were used to measure the lipid contents of the sperm and cervical mucus before and after migration. The concentrations of cholesterol, vitamin E, sphingomyelin, diacyls and plasmalogens in sperm were all approximately 45% lower after migration in cervical mucus and the cervical mucus was found to be enriched in some of these lipid species after the sperm migration. These results suggest that the cervical mucus selects a subpopulation of sperm with a lower lipid content. However, a concomitant efflux of various lipid classes from the sperm to the cervical mucus cannot be ruled out.

Background/aim: Concerns about the detrimental effects of occupational and environmental exposure on male reproductive function have been raised by reports of declining sperm quality over the last decades. The aim of this study was to investigate the association between altered semen parameters and exposure to occupational risk factors as assessed by questionnaire. Materials and methods:We conducted a cross-sectional questionnaire-based study among a population of 2122 men who underwent andrological investigation for couple infertility. All participants were interviewed and their semen samples were analyzed. Information about medical history and occupational exposure was used to classify participants into exposed and unexposed groups.Results: Exposure to pesticides was associated with a significantly higher risk of asthenozoospermia (adjusted odds ratio [OR] = 1.6; 95% CI, 1.0-2.4) and necrozoospermia (OR = 2.6; 95% CI, 1.4-4.7). Exposure to cement was found to be correlated with a higher risk of oligozoospermia (OR = 1.1; 95% CI, 0.9-1.4). There was no association between semen impairment and exposure to solvents, excess heat, or mechanical vibrations. Conclusion:We found an association between self-reported occupational exposure and altered semen parameters. These results support the usefulness of questionnaires for routine assessment and management of occupational exposures in infertile men.

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