OBJECTIVE--To investigate whether semen quality has changed during the past 50 years. DESIGN--Review of publications on semen quality in men without a history of infertility selected by means of Cumulated Index Medicus and Current List (1930-1965) and MEDLINE Silver Platter database (1966-August 1991). SUBJECTS--14,947 men included in a total of 61 papers published between 1938 and 1991. MAIN OUTCOME MEASURES--Mean sperm density and mean seminal volume. RESULTS--Linear regression of data weighted by number of men in each study showed a significant decrease in mean sperm count from 113 x 10(6)/ml in 1940 to 66 x 10(6)/ml in 1990 (p < 0.0001) and in seminal volume from 3.40 ml to 2.75 ml (p = 0.027), indicating an even more pronounced decrease in sperm production than expressed by the decline in sperm density. CONCLUSIONS--There has been a genuine decline in semen quality over the past 50 years. As male fertility is to some extent correlated with sperm count the results may reflect an overall reduction in male fertility. The biological significance of these changes is emphasised by a concomitant increase in the incidence of genitourinary abnormalities such as testicular cancer and possibly also cryptorchidism and hypospadias, suggesting a growing impact of factors with serious effects on male gonadal function.

https://www.bmj.com/content/bmj/305/6854/609.full.pdf

Evidence for decreasing quality of semen during past 50 years.

/pdf/evidence-for-decreasing-quality-of-semen-during-past-50-vlioqbfqzo.pdf

Evidence for Decreasing Quality of Semen During Past 50 Years

Selected practice recommendations for contraceptive use

Sperm antibodies: their role in infertility*

Recent reports have suggested that the incidence of genitourinary abnormalities in human males has increased during the past 50 years, including congenital abnormalities such as cryptorchidism and ...

Joseph E. Davis

Papers

Immunologic consequences of vasectomy.

Disappearance rate of spermatozoa from the ejaculate following vasectomy.

Glycerylphosphorylcholine and Carnitine in Normal Human Semen and in Postvasectomy Semen: Differences in Concentrations

Influence of Norepinephrine on the Motility of the Human Vas Deferens: A New Hypothesis of Sperm Transport by the Vas Deferens * †

Cutaneous metastases from prostatic carcinoma