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.

WHO laboratory manual for the examination and processing of human semen

https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.1939-4640.2002.tb02599.x

Sperm chromatin structure assay: its clinical use for detecting sperm DNA fragmentation in male infertility and comparisons with other techniques.

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

Evidence for Decreasing Quality of Semen During Past 50 Years

Computer assisted semen analyzers in andrology research and veterinary practice

External quality control in the andrology laboratory: an experimental multicenter trial.

The regulation of human implantation is still unknown. Evidence from mice suggests an essential role for several paracrine mediators but species differences with implantation in the human preclude the extrapolation of these concepts to humans. An intrauterine microdialysis device (IUMD), consisting of microdialysis tubing glued into a balloon catheter on one side and into a polypropylene tube on the other, allows a dynamic and accurate in-vivo measurement of uterine paracrine interactions in humans. Inserted into the uterine cavity in the form of a loop, it can be continuously perfused with saline to reveal a number of relevant cytokines and growth factors in uterine effluents of non-pregnant women in both follicular and luteal phases. These included interleukin (IL)-1alpha, IL-1beta, IL-6, leukaemia inhibitory factor (LIF), macrophage colony-stimulating factor (M-CSF), epidermal growth factor, vascular endothelial growth factor (VEGF), insulin-like growth factor binding protein-1 (IGFBP-1), prolactin, and human chorionic gonadotrophin (HCG). The source of intrauterine HCG is unclear since endometrial mRNA for the HCG beta-subunit is not revealed using reverse transcriptase polymerase chain reaction analysis. Applying urinary HCG locally via the IUMD profoundly alters endometrial secretory parameters. Prolactin, IGFBP-1, and M-CSF are significantly inhibited and VEGF is regulated in a biphasic manner involving early stimulation followed by inhibition of intrauterine levels. Use of the IUMD has thus shown that the urinary HCG preparations routinely used for ovulation induction and luteal support may directly alter endometrial function.

Novel insights into human endometrial paracrinology and embryo-maternal communication by intrauterine microdialysis

We evaluated a recently developed computerized semen analyser that detects spermatozoa not only by the criteria of size, contrast and movement but also by the morphological characteristics of the sperm tail. Comparison of the sperm concentration in 33 semen samples measured by conventional and by computerized semen analysis, as well as by flow cytometry, showed acceptable agreement between all three methods, although the mean differences and standard deviations were less for conventional than for computerized analysis when compared to flow cytometry as a reference method. Motility estimates were lower by the computer system for values between 1 and 40%. Higher motilities showed no systematic error. In conclusion, the improved algorithms for sperm detection yield more reliable data for sperm concentration and motility than previous systems of computerized semen analysis.

Computerized semen analysis with sperm tail detection

Ureteral obstruction--a complication of oocyte retrieval.

The pharmaceutical preparations for treating side effects, such as hot flashes, prostate enlargement and gynecomastia, during and/or after treatment with analogs or antagonists of gonadotropin-releasing hormone (GnRHa therapy) contain an effective amount of a chemically modified derivative of 17α-estradiol, a chemically modified derivative of 17β-estradiol and/or a chemical modified derivative of estriol. Pharmaceutical preparations containing estra 1,3,5(10)-triene-3,17β-diol-17-valerate as the effective ingredient are particularly preferred.

Joachim Neuwinger

Papers

External quality control in the andrology laboratory: an experimental multicenter trial.

Novel insights into human endometrial paracrinology and embryo-maternal communication by intrauterine microdialysis

Computerized semen analysis with sperm tail detection

Ureteral obstruction--a complication of oocyte retrieval.

Pharmaceutical preparations for treating side effects during and/or after GnRHa therapy