Decline In Semen Quality Research Articles

No decline in semen quality among potential sperm donors in Sydney, Australia, between 1983 and 2001.

To determine whether the quality of semen has changed over time in men screened for semen donation. All 448 men volunteering for semen donation between 1983 and 2001 at a donor insemination clinic in Sydney, Australia, were included in this longitudinal single centre observational analysis of semen parameters. There was no selection for fertility or marital status but all volunteers had to be aged between 18 and 40 years. There was no change in the total sperm count during the study period (r = 0.065, P = 0.17) using a linear regression model. The ejaculate volume did not change (r = 0.002, P = 0.97), while an increase in sperm motility was seen (Spearman R = 0.194, P < 0.001). The semen quality of volunteers for sperm donation presenting to our donor insemination clinic in Sydney between 1983 and 2001 has not declined.

Time Trends in Biological Fertility in Britain

Summary Background There is evidence of a decline in semen quality in some countries, including Britain, in recent decades. This retrospective cohort study examined the hypothesis that biological fertility had also declined. The trend in couple fertility was assessed by means of time to pregnancy (TTP)—a sensitive and validated measure of fertility. Methods A representative sample of the British population aged 16–59 years was surveyed. TTP was obtained for all births conceived after unprotected intercourse that began during 1961–93, excluding contraceptive failures. The sample size was 1540. Findings In contrast to the original hypothesis, this study found that fertility has increased; the rising trend was accompanied by slight dips during 1976–80 and 1986–90. These results were consistent between male and female respondents, and undiminished by adjustment for possible confounding factors. A stronger and more consistent relation was found with the year when unprotected intercourse started (a period effect) than with the year of birth of either partner (a birth cohort effect). Interpretation The findings could not be explained by trends in age at first birth, increased treatment of subfertility, or changes in oral contraceptive use. If a decline in male fertility has occurred, it has been more than compensated for by a countervailing increase in couple fertility.

Changing Male Reproductive Health: A Review of the Clinical Evidence?

Several lines of circumstantial evidence suggest that we may be seeing adverse changes in male reproductive health. A possible decline in semen quality has attracted most attention, but there are stronger indications of a rising incidence of testicular cancer, with increases observed in both Europe and the USA. There are striking geographic variations in both the incidence of testis cancer and in the observed rate of increase, and it is noteworthy that testis cancer is much more common in Denmark, where low sperm counts have been reported, than in Finland, where semen quality seems to be better. Another cause for concern is the rising incidence of congenital malformations of the male genital tract — cryptorchidism and hypospadias. In the UK, for example, rates of cryptorchidism have increased by as much as 65 to 77%. The data are harder to interpret on semen quality. In a meta-analysis, Carlsen et al. (1992) identified significant decreases over time in sperm concentration, corresponding to a fall of almost 50% between 1940 and 1990. Several groups have since examined secular trends in semen quality, with some reporting a downward trend and others no change. However, evidence has emerged of striking regional differences in semen quality, whether due to ethnic, genetic, environmental, or lifestyle factors remains to be determined.

Myth and reality of the decline in semen quality: An example of the relativity of data interpretation

Many hypotheses have been put forward to explain a suspected decline in semen quality. Up to now many sources of data were used but conflicting results are present in the literature. To study whether modifications of sperm parameters actually exist we used data from two groups of patients checked and two small groups of sperm bank donors selected at the beginning '80s and '90s. We tried to reduce bias to a minimum: all the semen analyses were carried out by the same biologist, using the same methods, groups were clinically evaluated by the same andrological team, the study groups were homogeneous for age, geographic-ethnic origin, residence, monthly-seasonal distribution and abstinence period. Comparing patients from the '80s and the '90s, sperm concentration and motility showed a significant reduction. Furthermore, the decrease in concentration and motility was mainly due to the higher age classes. In donors, no decline was observed. These results seem to indicate that sperm donors remain unaffected, while patients with lower levels of semen quality are experiencing a real decline. Unfortunately, many confounding variables, analyzed in detail in this review, still remain despite efforts at standardization.

Time trends in biological fertility in Britain

There is evidence of a decline in semen quality in some countries, including Britain, in recent decades. This retrospective cohort study examined the hypothesis that biological fertility had also declined. The trend in couple fertility was assessed by means of time to pregnancy (TTP--a sensitive and validated measure of fertility. A representative sample of the British population aged 16-59 years was surveyed. TTP was obtained for all births conceived after unprotected intercourse that began during 1961-93, excluding contraceptive failures. The sample size was 1540. In contrast to the original hypothesis, this study found that fertility has increased; the rising trend was accompanied by slight dips during 1976-80 and 1986-90. These results were consistent between male and female respondents, and undiminished by adjustment for possible confounding factors. A stronger and more consistent relation was found with the year when unprotected intercourse started (a period effect) than with the year of birth of either partner (a birth cohort effect). The findings could not be explained by trends in age at first birth, increased treatment of subfertility, or changes in oral contraceptive use. If a decline in male fertility has occurred, it has been more than compensated for by a countervailing increase in couple fertility.

Semen banking in patients with cancer: 20-year experience.

Modern techniques of banking sperm provide an effective way to preserve the option of future fertility for most teenagers and young men diagnosed with a variety of malignancies that will necessitate treatment with chemotherapy, pelvic surgery, or significant radiation doses to the testes. Results of cumulative data collected at the Cleveland Clinic Foundation from patients with testicular cancer, lymphoma, leukemia, sarcoma, carcinoma and other kinds of malignancy have revealed that: (1) pretreatment semen quality (pre-freeze and post-thaw) in patients with cancer is poorer compared with healthy donors; (2) the percentage decline in semen quality (from pre-freeze to post-thaw) in patients with cancer is similar to that of normal donors. This suggested that the effect of cryodamage on spermatozoa from patients with cancer is similar to that of normal donors. (3) The stage of cancer in patients with testicular cancer and Hodgkin's disease shows no relationship to their semen quality. Based on studies conducted at the Cleveland Clinic Foundation, we recommend that sperm cryopreservation be offered to all men of reproductive age who have malignancies. Cryopreservation is safe and inexpensive, and gives patients a chance to establish pregnancies in the future with an assisted reproductive technique.

Semen quality changes among 2343 healthy Slovenian men included in an IVF-ET programme from 1983 to 1996.

To determine whether semen quality in Slovenians has changed over 14 years (1983-96), we analysed retrospectively the semen of 2343 healthy men with a normal spermiogram, who were partners of women with tubal infertility included in the IVF-ET programme. Age at semen collection, duration of sexual abstinence, semen volume, sperm concentration, total sperm count, percentage of spermatozoa with progressive motility, and normal morphology were determined. Multiple regression analysis was used to assess the changes in sperm characteristics according to the year of semen collection, year of the man's birth and the duration of sexual abstinence. Semen volume, sperm concentration, sperm count and total sperm motility did not change between 1983 and 1996, whereas between 1988 and 1996 rapid progressive sperm motility decreased by 0.95% per year (p < 0.0001). Semen volume, sperm concentration, and sperm count increased with duration of sexual abstinence. After adjustment for the year of semen collection and duration of sexual abstinence, multiple regression analysis showed that sperm concentration decreased by 0.67% per each successive year of birth (p = 0.03). Thus the sperm concentration decreased from 87.6 x 10(6)/mL in men born in the 1940s to 77.3 x 10(6)/mL in those born between 1956 and 1960. After 1960, sperm concentration was found to increase. In 2343 healthy men, no decline in semen quality, except in rapid progressive motility, was observed in the study period. Lower sperm concentration was found among men born between 1950 and 1960. This could be related to worse socio-economic status, stress or negative environmental factors in this time period.

Relationship between psychological stress and semen quality among in-vitro fertilization patients.

The purpose of this study was to determine the relationship between psychological stress and semen quality among men undergoing in-vitro fertilization (IVF). We assessed psychological variables, including self-reported stress, and sperm parameters in a group of 40 men undergoing IVF for the first time at a pre-IVF sampling period (T1) and at the time of egg retrieval (T2). Thirty-one patients completed the study. Results indicated that total and motile sperm concentration, total motile spermatozoa, and lateral head displacement decreased significantly from T1 to T2 in a high percentage of participants. In addition, the perceived importance of producing a semen specimen increased significantly (P = 0.001) from T1 to T2, and this change was significantly correlated (P < 0.05) with diminished semen quality at the time of oocyte retrieval. No decline in the semen quality or increase in perceived stress at egg retrieval was observed at T2 in male factor patients (n = 7). This study provides evidence for a significant decline in semen quality of male IVF patients at egg retrieval and demonstrates an inverse relationship between semen quality and specific aspects of psychological stress.

DECLINING MALE FERTILITY AND ENVIRONMENTAL FACTORS

Male reproductive function has recently attracted increasing attention due to reports on time-related decline in semen quality. Analysis of retrospective data indicates that sperm counts may have declined in some parts of the world, but there seem to be regional differences both in the quality of semen and regarding the secular trend. Whereas data on sperm counts may be somewhat difficult to interpret, there is no doubt that incidence of testicular cancer has increased worldwide. In occupational studies, only a few types of exposures were shown to have an impact on male reproductive function; lifestyle and general environmental factors may play a more important role. Prospective studies on secular and geographic trends in male reproductive function are warranted.

Is male reproductive health at risk? Longitudinal semen analysis studies.

Considerable controversy remains as to whether a decline in sperm production has occurred in normal men over the past 50 years. Semen analysis studies must log transform the sperm concentration data to obtain a normal distribution and obtain multiple (3-6) semen samples. These methodological procedures were followed in a longitudinal study (1972-93) of 510 healthy adult US men. Sperm concentration semen volume and sperm morphology data were obtained for samples obtained after 2-7 days of sexual abstinence. A median of 6 samples were obtained per subject. The geometric mean sperm concentrations ranged from 49.2 x 10 to the sixth power/ml in the first trial during 1972-73 to 51.96 in the last study during 1992-93. The highest geometric mean (76.4) was obtained during 1987-89. There was no significant decrease in sperm concentration semen volume or total sperm per ejaculate during the study period. Although these findings suggest there has been no decline in semen quality over the past 21 years such deterioration may have occurred in other geographic areas or in small vulnerable populations such as men exposed to environmental toxins.

Decreased fertility in Britain compared with Finland

SummaryBackground There has been much interest in the apparent decrese in semen quality. Because the evidence for such a decrease is open to criticism, a different type of evidence is needed. Finland seems to have escaped this decrease, as well as other disorders of the male reproductive tract, notably testicular cancer. If there has been a true decrease, the implications for fertility are unknown.Methods The most sensitive functional measure of fertility is time to pregnancy (TTP); this can be studied retrospectively at group level with a high degree of validity. To test the hypothesis that Finnish men are more fertile than British men, TTP distributions from published Finnish studies and data from Britain were compared. Two comparisons were made: a pair of antenatal studies, and a pair of cross-sectional studies.Findings In both comparisons, fertility was statistically significantly greater in Finland than in Britain. The findings did not seem to be due to methodological problems; in particular, the results could not be attributed to differences in frequency of intercourse, since this would have had the opposite effect on sperm concentration and on TTP.Interpretation The previously reported difference in sperm counts between Finland and elsewhere in northwest Europe (including Britain) is probably not artefactual, suggesting that the reported world-wide decline in semen quality is also real. Reasons for the "Finnish exception" may include maternal smoking, which used to be lower in Finnish women than elsewhere, and which might affect developing male offspring.

Data from men in greater Seattle area reveals no downward trend in semen quality: further evidence that deterioration of semen quality is not geographically uniform

To determine whether there has been a decline in semen quality in a group of healthy men during the past 21 years. Retrospective analysis of the relationship between time and changes in semen parameters over 21 years using regression analysis. A tertiary university center. Five hundred ten healthy, normal men who donated multiple semen samples as participants in clinical studies between 1972 and 1993. Sperm concentration, semen volume, total numbers of sperm per ejaculate, and percent spermatozoa with normal morphology. There was no decrease in sperm concentration, semen volume, total number of sperm per ejaculate, and percent normal sperm morphology in 510 healthy men studied between 1972 and 1993. We conclude that in this population of healthy young men there has not been any decline in semen quality in the past 21 years.

Geographic variations in sperm counts: a potential cause of bias in studies of semen quality

To determine whether geographic variations in sperm counts might bias conclusions drawn from studies of semen quality. Reanalysis of published data from a meta-analysis of 61 studies from 1938 to 1990 that concluded a worldwide decline in semen quality over the last 50 years. Influence of geographic location on sperm counts. Of 61 studies in the meta-analysis, only 20 included > or = 100 men. These 20 studies collectively comprised 91% of the total men studied. We focused our reanalysis on these 20 studies. Of the studies before 1970, all were from the United States and 80% were from New York. These studies represented locations with the highest sperm counts. In contrast, after 1970, 80% of the studies were from locations not represented earlier, including five studies from third world countries, where sperm counts were low. Sperm counts vary dramatically among different geographic locations.

Worldwide decline in semen quality might be due to smoking

EDITOR,—While there has been much concern recently about the potential effect of environmental oestrogens on male reproduction, studies of the association between cigarette smoking and sperm concentration, as well as patterns of cigarette consumption, support the notion that cigarette smoking may have contributed considerably to the worldwide decline in semen quality. Carlsen et al systematically reviewed 61 studies of semen quality conducted over 50 years and found that mean sperm concentration worldwide fell by half from …

Decline in semen quality among fertile men in Paris during the past 20 years

International Journal of Gynecology & ObstetricsVolume 51, Issue 1 p. 94-95 Fertility and sterility Decline in semen quality among fertile men in Paris during the past 20 years First published: October 1995 https://doi.org/10.1016/0020-7292(95)80039-FAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume51, Issue1October 1995Pages 94-95 RelatedInformation

Decline in Semen Quality Among Fertile Men in Paris During the Past 20 Years

Background Several studies have suggested a population-wide decline in the quality of semen over the past 50 years, but clear evidence of decreasing semen quality in recent decades is lacking. Methods From 1973 through 1992 we measured the volume of seminal fluid, the sperm concentration, and the percentages of motile and morphologically normal spermatozoa in 1351 healthy fertile men. The data on the semen samples were collected at one sperm bank in Paris. The data in each calendar year were analyzed as a function of the year of donation, the age of each patient, the year of birth, and the duration of sexual abstinence before semen collection. Results There was no change in semen volume during the study period. The mean concentration of sperm decreased by 2.1 percent per year, from 89 ×106 per milliliter in 1973 to 60×106 per milliliter in 1992 (P<0.001). During the same period the percentages of motile and normal spermatozoa decreased by 0.6 percent and 0.5 percent per year, respectively (both P<0.001). ...

Cryopreservation and semen quality in patients with Hodgkin's disease.

Cryopreservation of semen from patients with Hodgkin's disease yields fewer motile sperm than from fertile men without Hodgkin's disease. However, although poor sperm quality and subfertility have been associated with Hodgkin's disease, whether the disease adversely affects sperm quality is not clear because many studies evaluated semen quality after chemotherapy or radiation therapy had begun. Furthermore, the effect of cryopreservation on semen quality in these patients is unknown. This study investigated pretreatment sperm quality and the effect of cryopreservation on semen quality in patients with Hodgkin's disease. Specimens from 39 patients with Hodgkin's disease and 30 normal volunteers who underwent sperm banking over a 5-year period were analyzed. No patient had undergone chemotherapy or radiation therapy before sperm banking. The nitrogen vapor technique, using Test-Yolk buffer with glycerol as a cryoprotective agent, was used for cryopreservation. Prefreeze and postthaw motile sperm count (MSC) and motion characteristics, namely motility, curvilinear velocity (VCL), linearity, amplitude of lateral head movement (ALH), and motility index, were compared between the two groups. Prefreeze values for MSC (P = 0.0001), motility (P = 0.0001), motility index (P = 0.0001), and VCL (P = 0.0019) differed significantly between patients and donors. Except for linearity and ALH, postthaw sperm MSC, motility, VCL, and motility index decreased significantly (P = 0.0001) in both groups. However, the percentage decline in semen quality from prefreeze to postthaw values did not differ significantly between donors and patients. The pretreatment semen quality in patients with Hodgkin's disease is poor compared with that of normal fertile men. However, half the patients had a normal MSC, so a clinical diagnosis of Hodgkin's disease does not predict cryopreservation outcome adequately. Semen cryopreservation should be encouraged as a routine part of the therapeutic management of men of reproductive age who will undergo chemotherapy or radiation therapy for Hodgkin's disease.

How much of the human disease burden is attributable to environmental chemicals?

According to the evaluations made by IARC, 66 agents or exposures have been recognised as human carcinogens. About 60% of all cancer cases occur in people over 65 years of age, which is indeed the most important risk factor for cancer, including both the duration of exposure to the variety of carcinogenic agents and allowing expression of genetically determined disorders. Diet as a source of mutagens as well as other environmental mutagens may affect blood pressure either directly or by favouring the development of arteriosclerosis: mutagens have been shown to accelerate arteriosclerotic plaque development. Some concern has also been expressed on the possible adverse effect that environmental chemicals may have on reproductive ability, on the basis of the decline in semen quality reported over the past decades. Better defining the role of aetiological agents would result in a more precise definition of attributable risks. Of particular interest to the latter goal are the studies of inter-individual variability in the susceptibility to carcinogens, which will hopefully contribute to define the role of low-level exposure to carcinogens.

Decline in Semen Quality among Fertile Men in Paris during the Past 20 Years

Several studies have suggested a population-wide decline in the quality of semen over the past 50 years, but clear evidence for decreasing semen quality in recent decades is lacking. From 1973 through 1992 we measured the volume of seminal fluid, the sperm concentration, and the percentages of motile and morphologically normal spermatozoa in 1351 healthy fertile men. The data on the semen samples were collected at one sperm bank in Paris. The data in each calendar year were analyzed as a function of the year of donation, the age of each patient, the year of birth, and the duration of sexual abstinence before semen collection. There was no change in semen volume during the study period. The mean concentration of sperm decreased by 2.1 percent per year, from 89 x 10(6) per milliliter in 1973 to 60 x 10(6) per milliliter in 1992 (P < 0.001). During the same period the percentages of motile and normal spermatozoa decreased by 0.6 percent and 0.5 percent per year, respectively (both P < 0.001). After adjustment in multiple regression analyses for age and the duration of sexual abstinence, each successive calendar year of birth accounted for 2.6 percent of the yearly decline in the sperm concentration and for 0.3 percent and 0.7 percent, respectively, of the yearly declines in the percentages of motile and normal spermatozoa (all P < 0.001). During the past 20 years, there has been a decline in the concentration and motility of sperm and in the percentage of morphologically normal spermatozoa in fertile men that is independent of the age of the men.

Evidence for Decreasing Quality of Semen During Past 50 Years

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.