Incidence of disorders of spermatogenesis in middle aged finnish men, 1981-91: two necropsy series.

OBJECTIVE

To investigate if the incidence of disorders of spermatogenesis and testicular tissue morphology have changed in middle aged Finnish men over 10 years.

DESIGN

Two necropsy series completed in 1981 and in 1991.

SETTING

Department of Forensic Medicine, University of Helsinki, Finland.

SUBJECTS

528 men, aged 35 to 69 years, subjected to medicolegal necropsy.

MAIN OUTCOME MEASURES

Scoring of spermatogenesis and morphometric analysis of testicular tissue components. Individual risk factors for testicular disorders obtained by postmortem blind interviews with acquaintances.

RESULTS

Normal spermatogenesis was found in 41.7% of the men (mean age 53.1 years). Between 1981 and 1991, the ratio of normal spermatogenesis decreased significantly (odds ratio 3.5; 95% confidence interval 2.5 to 5.1) from 56.4% to 26.9%, with a parallel increase in the incidence of partial and complete spermatogenic arrest (2.1; 1.4 to 2.9 and 2.9; 1.7 to 5.0, respectively). During this period, the size of seminiferous tubules decreased, the amount of fibrotic tissue increased, and the weight of testicles decreased significantly. Alterations in testicular characteristics over time could not be explained by changes in body mass index, smoking, alcohol drinking, or exposure to drugs.

CONCLUSIONS

The incidence of normal spermatogenesis decreased among middle aged Finnish men from 1981 to 1991, and the incidence of disorders of spermatogenesis and pathological alterations in testicles increased. Deteriorating spermatogenesis may thus be one important factor in the explanation of declining sperm counts observed worldwide.