Age thresholds for changes in semen parameters in men

Basic semen parameters are consistent through 34 years of age. Thereafter, ejaculate volume, sperm numbers, motility, proportions of sperm of normal morphology, and the ratio of Y- to X-bearing sperm decline.

Bronte A. Stone, B.Ag.Sc., M.Ag.Sc., Ph.D., Bronte Allan Stone, Ph.D., Allyse Alex, M.Sc., Lawrence B. Werlin, M.D., Richard P. Marrs, M.D.

Volume 100, Issue 4, Pages 952-958, October 2013


To determine whether age thresholds for elements of semen quality exist.

Retrospective analysis (covariance and point-change analysis) of results of 4,822 semen analyses and 259 fluorescence in situ hybridization (FISH) analyses.

Reference laboratory within an infertility clinic.

A total of 5,081 men aged 16.5–72.3 years.


Main Outcome Measure(s):
Ejaculate volume, sperm concentration, sperm motility, sperm motion parameters, strict morphology, and results of FISH analysis.

Measured parameters of ejaculates did not change before 34 years of age. Immediately thereafter, total sperm numbers (and total motile) declined. Sperm concentration and the proportion of sperm of normal morphology declined after 40 years. Sperm motility and progressive parameters of motile sperm fell after 43 years and ejaculate volume after 45 years. The ratio of Y:X-bearing sperm in ejaculates decreased only after 55 years.

Our findings project a declining likelihood of pregnancy following intercourse with men >34 years old, independent from the woman’s age and increasing with advancing age. Age-related mechanisms associated with this oligoasthenoteratozoospermic progression are discussed.

  • Interesting article trying to further demonstrate the effect of aging on sperm. Like Audrey mentioned, men were not followed longitudinally so the effect of age cannot be answered. Since there isn’t an accurate sperm function testing nor do we know the minimum sperm needed for successful pregnancy, the true “advanced paternal age” is yet to be determined.

  • Audrey Gaskins

    This was an interesting study on the association between age and semen quality. I particularly enjoyed how the authors focused on semen quality parameters outside the conventional ones as I thought this added to their ability to comment on the possible age-related mechanisms. My one qualm, however, is the choice of title which is a bit misleading. The current title implies that the authors were looking at the change in semen parameters within men as they age, which they were not.

  • This is a good study with a very large cohort.

    There is so much that we still have to learn about the semen analysis. With all of its imperfections, I still can’t explain to a patient with unexplained infertility and normal female evaluation why they can’t conceive despite a normal semen analysis, and conversely how a patient with <1 motile sperm / hpf after a vasectomy causes a pregnancy despite such low numbers.

    Can we conclude from this that there is a definitive cutoff for counseling men about the risks of "Advanced Paternal Age"?

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