Sperm Counts Decline of 50% since 1973, more so among older men, and yet…

Here’s the gist of what I’m going to say here:

  • Over the last 40 years male sperm count has decreased by 50% in all industrial nations and it keeps going down.
  • 15% of couples are unable to have a baby (are infertile).
  •  Half the time a couple can’t have a baby male infertility is involved.   30% of the time it is due to male infertility, and 20% of the time due to a combination of BOTH male and female infertility.
  • Because of decrease sperm count, men over 40 are 30% less likely to conceive a child then men under 40.
  • Despite this, men continue to date younger women, and mate with younger women.

Men are coupled with women who are 2.3 years younger then them, on average.  Two thirds of coupled men are with a woman at least a year younger. (1)

Men in their late 40s look for online dates most frequently among profiles of women from 20 to 24.   In contrast, as women get older they look for men their own age. (2)

Infertility is defined as the inability to achieve pregnancy after one year of unprotected intercourse. An estimated 15% of couples meet this criterion and are considered infertile, with approximately 35% due to female factors alone, 30% due to male factors alone, 20% due to a combination of female and male factors, and 15% unexplained.(3)

Men over 40 are 30% less likely then men under 40 to conceive a child, based on a study of 8,559 pregnancies over a 12 month period.

Based on a study of 315 patients, men who have been exposed to common chemicals known as parabens have lower testosterone levels and more sperm that are abnormally shaped and slow moving, according to a study that suggests these ingredients may contribute to infertility. Parabens are found in many common soaps and detergents.  (4)

Based on 185 studies from 1973 to 2011, there was a steep decline of more than 50% in both sperm concentration and total sperm count among men from Western countries. The researchers also restricted the analysis to studies after 1995 and reported that the decline does not appear to be abating. The new report reveals that sperm counts among men in Western countries, including men in North America, Australia, New Zealand and Europe, have dropped more than 50% in less than 40 years. Sperm count is currently considered the best measure of male fertility. (5)

(1) US Census data

(2) OK Cupid data

(3) Kassem Faraj; Chief Editor: Edward David Kim, MD, FACS et al. Male Infertility, in MedScape. Jun 07, 2016

(4)  Joanna Jurewicz; Michał Radwan, et all. Human Semen Quality, Sperm DNA Damage, and the Level of Reproductive Hormones in Relation to Urinary Concentrations of Parabens. Journal of Occupational and Environmental Medicine. Publish Ahead of Print():, JUL 2017

(5) Hagai Levine Niels Jørgensen Anderson Martino-Andrade Jaime MendiolaDan Weksler-Derri Irina Mindlis Rachel Pinotti Shanna H. Swan. Temporal trends in sperm count: a systematic review and meta-regression analysis  Human Reproduction Update, 25 July 2017https://doi.org/10.1093/humupd/dmx022

Some citations in this blog were gathered from an article by Mona Chalabi, data editor of The Guardian, in the NYT,  Oct 1, 2017, Sunday Review Page 2.