Virility

Male virility

Evidence shows that increased male age is associated with a decline in semen volume, sperm motility, and sperm morphology. In studies that controlled for female age, comparisons between men under 30 and men over 50 found relative decreases in pregnancy rates between 23% and 38%.

Older men have lower semen parameters resulting in lower fertility potential. The effects of aging on semen quality are summarized below based on a study of 1,219 subjects:

Sperm count declines with age, with men aged 50–80 years producing sperm at an average rate of 75% compared with men aged 20–50 years. However, an even larger difference is seen in how many of the seminiferous tubules in the testes contain mature sperm:

• In males 20–39 years old, 90% of the seminiferous tubules contain mature sperm.
• In males 40–69 years old, 50% of the seminiferous tubules contain mature sperm.
• In males 80 years old and older, 10% of the seminiferous tubules contain mature sperm." Effect of Age on Male Fertility" Seminars in Reproductive Endocrinology. Volume, Number 3, August 1991. Sherman J. Silber, M.D.

Research shows increased risks for health problems for children of older fathers. A large-scale Israeli study found that the children of men who were 40 or older were 5.75 times more likely than children of men under 30 to have an autism spectrum disorder, controlling for year of birth, socioeconomic status, and maternal age. Increased paternal age has also been correlated to schizophrenia in numerous studies.{{cite journal |author=Malaspina D |title=Paternal Age and Sporadic Schizophrenia: Evidence for De Novo Mutations

Researchers have found evidence to suggest overweight and obesity may cause subtle damage to sperm and prevent healthy pregnancy. They say fertilization was 40% less likely to succeed when the father was overweight.

The American Fertility Society recommends an age limit for sperm donors of 50 years or less, and many fertility clinics in the United Kingdom will not accept donations from men over 40 or 45 years of age.

References

References

1. {{harvnb. Schiebinger. 1993
2. ''[[Oxford English Dictionary]]''
3. ''[[Oxford English Dictionary]]''
4. Kidd, S. A., Eskenazi, B., Wyrobek, A. J.. (February 2001). "Effects of male age on semen quality and fertility: a review of the literature". Fertil. Steril..
5. (August 2017). "Impact of age on semen parameters in male partners of infertile couples in a rural tertiary care center of central India: A cross-sectional study". International Journal of Reproductive Biomedicine.
6. Reichenberg, A.. (September 2006). "Advancing paternal age and autism". Arch. Gen. Psychiatry.
7. Malaspina, D.. (April 2001). "Advancing paternal age and the risk of schizophrenia". Arch. Gen. Psychiatry.
8. Sipos A. (November 2004). "Paternal age and schizophrenia: a population based cohort study". BMJ.
9. (18 October 2010). "Obesity | Fat men linked to low fertility". Sydney Morning Herald.
10. Plas, E., Berger, P., Hermann, M., Pflüger, H.. (August 2000). "Effects of aging on male fertility?". Experimental Gerontology.
11. "[http://www.spermdonorforum.com/documents/sperm_donor_clinics_uk_2007.pdf Age Limit of Sperm Donors in the United Kingdom]", PDF file