Assessment of the relationship of sperm morphology with seminal and other clinical conditions of semen donors

Age-related decline in sperm deoxyribonucleic acid integrity in patients evaluated for male infertility

The purpose of this study was to analyze the relationship of male age and DNA integrity in men presenting for investigation of infertility. We found that men 45 years and older had significantly greater DNA fragmentation than younger men.

Mini-review of studies on the effect of smoking and drinking habits on semen parameters

This article aims at evaluating the impact of cigarette smoking and alcohol consumption on different semen parameters (volume, concentration, motility, morphology, total sperm count and viability), by reviewing all the published literature on smoking, alcohol and sperm morphology. The studies on smoking and sperm abnormalities show a limited effect of smoking on conventional sperm parameters. The data on alcohol are more sparse, and show an apparent protective effect of moderate alcohol drinking on sperm parameters, probably due to the antioxidant effect of some alcoholic beverages. Unfortunately, none of the studies that considered both alcohol and smoking habits conducted the analysis of the joint effect of the two exposure factors. More standardized laboratory assays and increased sample size studies involving subjects with various level of exposure to alcohol and smoking are needed to better establish the role of these factors in male infertility.

Effects of male age on semen quality and fertility: a review of the literature

OBJECTIVE

To review the literature on the association between male age and semen quality (semen volume, concentration, motility, and morphology) and fertility status (pregnancy rate and time to pregnancy/subfecundity).

METHOD(S)

Review of English language-published research over the last 20 years from January 1, 1980, through December 31, 1999, using MEDLINE and Biosis databases. Studies with insufficient numbers of subjects, case reports, case series, or anecdotal data were excluded.

RESULT(S)

Among the methodologically stronger studies, decreases in semen volume of 3%-22%, decreases in sperm motility of 3%-37%, and decreases in percent normal sperm of 4%-18% were likely when comparing 30-year-old men to 50-year-old men. Most studies examining fertility status suggest a relationship between male age and fertility, but the results are most likely confounded by female partner age. Among studies that did control for female age, comparisons between men under 30 and men over 50 found relative decreases in pregnancy rates between 23% and 38%. A comparison of the various age categories showed that the increased risks for subfecundity ranged from 11% to 250%.

CONCLUSION(S)

The weight of the evidence suggests that increased male age is associated with a decline in semen volume, sperm motility, and sperm morphology but not with sperm concentration.