Year of Birth and Sperm Count in 10 Danish Occupational Studies

Objectives Several reports indicate a secular decline of human sperm counts. It is still not known if these findings are artifacts related to shortcomings in the data and applied methodologies. Even less is known about possible mechanisms, but it has been proposed that potential changes may be relat...

Full description

Saved in:
Bibliographic Details
Published in:Scandinavian Journal of Work, Environment ＆ Health Environment ＆ Health, 1998-10, Vol.24 (5), p.407-413
Main Authors: Bonde, Jens Peter E, Jensen, Tina Kold, Larsen, Solveig Brixen, Abell, Anette, Scheike, Thomas, Hjollund, Niels Henrik I, Kolstad, Henrik A, Ernst, Erik, Giwercman, Aleksander, Skakkebæk, Niels E, Keiding, Niels, Olsen, Jørn
Format: Article
Language:English
Subjects:
Adult
Aging - physiology
Analysis. Health state
Biological and medical sciences
Chemical hazards
Childhood
Cross-Sectional Studies
Denmark
Epidemiology
Fertility
General aspects
Humans
Linear Models
Male
Medical sciences
Men
Metalworkers
Occupations
Public health. Hygiene
Public health. Hygiene-occupational medicine
Regression coefficients
Semen
Semen analysis
Sexual abstinence
Sperm Count
Spermatozoa
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Objectives Several reports indicate a secular decline of human sperm counts. It is still not known if these findings are artifacts related to shortcomings in the data and applied methodologies. Even less is known about possible mechanisms, but it has been proposed that potential changes may be related to disruption of the hormonal regulation of testicular development in prenatal life. The objective of this study was to examine whether sperm count was related to year of birth. Methods An analysis was made of the sperm count of 1196 men participating in 10 cross-sectional occupational sperm studies in 3 regions of Denmark from 1986 through 1995. Results The median sperm concentration was 63 million per milliliter for men born in 1937—1949 and 52 million per milliliter for men born in 1970 or later, and the median total sperm was 206 million and 117 million, respectively. The inverse relationship between sperm concentration and year of birth was statistically significant even after adjustment for duration of sexual abstinence, season of the year, and study population. However, bias because of differential participation related to age and fertility or lack of comparability across the populations cannot be ruled out. Conclusions The apparent decline of sperm count with increasing year of birth is compatible with the hypothesis of a common risk factor for male reproductive health operating in prenatal life or early childhood, but the evidence is circumstantial. Age-related selection bias is an alternative and perhaps not a less likely explanation.
ISSN:0355-3140
1795-990X
DOI:10.5271/sjweh.362