scholarly journals Secular variations in sperm quality: fact or science fiction?

2002 ◽  
Vol 18 (2) ◽  
pp. 403-412 ◽  
Author(s):  
Luc Multigner ◽  
Alejandro Oliva

The debate concerning the possible degradation in human sperm quality began in the 1970s, was revived at the beginning of the 1990s and has continued to mobilize the scientific community ever since. After the meta-analysis by Carlsen et al. (1992) showing a decline in human semen quality over the last 50 years, several groups investigated the sperm characteristics of more or less homogeneous groups of men who had provided semen at the same center for 10 to 20 years. A significant decrease in sperm concentration was reported in some studies, but not in others. Meanwhile, there is an increasing number of reports suggesting that physical and chemical factors introduced and spread by human activity in the environment may have contributed to sperm decline. At the end of the 20th century the debate on declining semen quality is not closed. The lack of certainty and the serious consequences that such a decline would have on the fertility of human populations make this an important public health issue at the start of the 21st century. For this reason, intensive research should be developed in both fundamental and epidemiological domains, particularly in South America, where industrial and agricultural pollution pose a serious threat to the population.

2001 ◽  
Vol 100 (6) ◽  
pp. 613-618 ◽  
Author(s):  
Julie H. MITCHELL ◽  
Elizabeth CAWOOD ◽  
David KINNIBURGH ◽  
Anne PROVAN ◽  
Andrew R. COLLINS ◽  
...  

Animal studies and human intervention trials have demonstrated the cancer chemopreventive properties of plant phytoestrogens, and phytoestrogen supplements are now widely available ‘over-the-counter’. However, consumption of phytoestrogen-rich diets can cause impaired fertility and reproductive tract disorders in some animals and the apparent decline in human sperm quality over recent decades may be related to increased exposure to environmental endocrine disruptors. The present study determines the effects of a short-term phytoestrogen supplement on semen quality and serum sex steroid and gonadotrophin levels in human males. Healthy volunteers took a supplement containing 40 mg of isoflavones daily for 2 months and donated blood and semen samples monthly for 2 months before and 4 months after supplementation. Semen samples were analysed for ejaculate volume, sperm concentration, total sperm count, motility and morphology. Blood samples were analysed for sex hormone and gonadotrophin levels and phytoestrogen concentrations, and testicular volume was measured using an orchidometer. The phytoestrogen supplement increased plasma genistein and daidzein concentrations to approx. 1 µM and 0.5 µM respectively; yet, there was no observable effect on endocrine measurements, testicular volume or semen parameters over the study period. This is the first study to examine the effects of a phytoestrogen supplement on reproductive health in males. We conclude that the phytoestrogen dose consumed had no effect on semen quality.


2003 ◽  
Vol 50 (1) ◽  
pp. 197-203 ◽  
Author(s):  
Stanisław Horak ◽  
Joanna Polańska ◽  
Piotr Widłak

Progressive decline in fertility and sperm quality has been reported over the last few decades, especially in industrialized nations. It has been proposed that exposure to factors that induce damage in DNA of spermatogenic cells may significantly contribute to impaired fertility. Here, the (32)P-postlabelling method was used to analyze the levels of bulky DNA adducts in sperm cells in a group of 179 volunteers, either healthy subjects or patients with an impaired fertility. The levels of DNA adducts were 1.35-fold higher in the infertile group as compared to healthy individuals (P = 0.012). Similarly, a significant negative correlation between the levels of DNA adducts and measures of semen quality (sperm concentration and motility) has been observed (P


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Juliana R. Pariz ◽  
Caroline Ranéa ◽  
Rosa A. C. Monteiro ◽  
Donald P. Evenson ◽  
Joël R. Drevet ◽  
...  

Cryopreservation processes can damage spermatozoa and impair structural and functional cell characteristics. Plasma, nuclear membranes, and cellular organelles can suffer from the freeze and thaw process. This study evaluates the protective and stimulant effect of melatonin and caffeine supplementation on the functional characteristics of human spermatozoa before and after freezing. Thirty seminal samples from normozoospermic men aged 19–45 years old collected between October 2012 and May 2017 were included. Semen samples were supplemented with either 2 mM melatonin (MEL) prior to cryopreservation, 2 mM caffeine (CAF) in postthaw, or CAF and MEL (CM) in precryopreservation and postthaw, respectively. Kinetics and seminal parameters, mitochondrial activity, DNA fragmentation, and reactive oxygen species (ROS) levels were analyzed before and after cryopreservation. A significant reduction in sperm concentration, total and progressive motility, sperm kinetics, and mitochondrial activity, as well as a significant increase in DNA fragmentation and ROS production in postthaw samples compared to fresh samples, was identified. After administration of a caffeine and/or melatonin supplement, there was a significant increase in progressive motility in the CAF (p=0.005) and CM (p=0.048) groups, as well as mitochondrial activity in the CM group (p<0.05). Cryopreservation has negative effects on overall sperm quality and increases ROS production. A combination of caffeine and melatonin in prefreeze and postthaw sperm samples has proven to be a very effective and simple way to improve semen quality. This will be particularly useful for initial low-quality semen samples, those which suffer the most from the freezing/thawing process.


2020 ◽  
Vol 20 (2) ◽  
pp. 198-202 ◽  
Author(s):  
Mohammad Motamedifar ◽  
Yalda Malekzadegan ◽  
Parisa Namdari ◽  
Behzad Dehghani ◽  
Bahia Namavar Jahromi ◽  
...  

Introduction: Infertility considered as a social and public health issue and estimated that most of these infertile couples are residents of developing countries. Infectious diseases including the history of Sexually Transmitted Infections (STIs) may impact on male reproductive function. Therefore, the present study aimed to investigate the prevalence of bacterial contaminants of semen and probable association with sperm quality of infertile men in Iranian population. Methods: The study population consisted of 200 infertile men and 150 fertile men attending an infertility Center in southwestern Iran during the study period in 2015. The assessment of sperm parameters was according to the World Health Organization (WHO) guidelines. The presumptive pathogens were identified using standard microbiology tests and confirmed by specific PCR primers. Results: The prevalence of bacteriospermia in the semen of the infertile group was significantly higher than that in the fertile group (48% vs. 26.7%, P <0.001). The microbiological analysis of samples showed that the most abundant species of bacteria in semen of infertile men were Chlamydia trachomatis (12.5%) followed by Neisseria gonorrhoeae (11%). On the other hand, in the control group, Lactobacillus spp. (17.3%) was the most isolated pathogen. Results showed that the presence of N. gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Haemophilus, and Klebsiella was significantly associated with sperm abnormality. Conclusion: Based on our findings, it seems that bacteriospermia is associated with alterations in the properties of semen which may lead to a decrease in the fertilization potential of sperm. Therefore, immediate and appropriate treatment is necessary before investigating every other possible cause of infertility.


Biomonitoring ◽  
2014 ◽  
Vol 1 (1) ◽  
Author(s):  
M.M. Leijs ◽  
L.M. van der Linden ◽  
J.G. Koppe ◽  
K. Olie ◽  
W.M.C. van Aalderen ◽  
...  

AbstractPolychlorinated biphenyls (PCBs) and dioxins (PCDDs/Fs) are well-known endocrine disrupters. This paper strives to elucidate the data on reproductive consequences of perinatal dioxin and PCB exposure in men and women. We focused on the following end-points: sex-ratio, endometriosis, menstrual cycle characteristics, sperm quality, and prematurity. We summarize 46 papers and compare their results including effects seen after exposure to background concentrations. Seven of twelve studies showed a decrease in sex-ratio after parental dioxin or PCB exposure. In three of the seven studies, effects were seen after paternal exposure and in three after maternal exposure. In eight of the nine studies on menstrual cycle characteristics, abnormalities were associated with PCB or dioxin exposure, however the results differed. In three studies PCB and TCDD were associated with longer menstrual cycles, while three studies indicated that an increase in PCB/PCDF exposure was associated with shorter cycles. Five studies showed effects on menstrual bleeding with higher PCB or dioxin exposure. A higher rate of irregular menstrual cycles in exposed women was seen in four studies. The conflicting outcomes probably result from variability in study design, timing of exposure and endocrine disrupting properties of the measured congeners. Nine of sixteen studies detected higher PCB or dioxin exposure in women with endometriosis. However, the manner of diagnosing endometriosis and the character of the studies varied from prospective to retrospective. Five of eight studies focusing on sperm quality showed that men, with higher serum concentrations of PCBs and/or PCB congeners and/or PCDFs, had reduced sperm quality, including increased abnormal morphology and reduced motility. The exposure timeframe seemed important here. There are two studies addressing preterm birth in relation to PCBs, one mentioned a shortening of three days of gestational age, two other studies did not find a relation. Recently one study related a shorter gestational age of half a week with overall dioxin activity measured with the CALUX method in cord blood, particularly in boys. In conclusion, exposure to PCBs and dioxins has a negative effect on the reproductive systems of human populations. Although some speculations have been made, the exact mechanism of these effects and the interactions of these compounds with other endocrine disruptors are not yet known. Age at exposure and congener specific properties are probably crucial in interpreting the observed results.


Author(s):  
Angela H Cliff ◽  
J H Dunne ◽  
P R English ◽  
J S M Hutchinson ◽  
O Macpherson

It is well established that high environmental temperature can have adverse effects on sperm concentration and the normality of sperm in the boar. Induced abnormalities include reduced motility, abnormal heads, proximal droplets, coiled and bent tails and abnormal acrosomes (Malmgren and Larsson, 1989). While all stages of spermatogenesis can be adversely affected, the primary spermatocytes are most vulnerable to these influences. Since spermatogenesis occurs over 45 days, any adverse effects of elevated ambient temperature can affect sperm quality for around 6 weeks. The maximum period of infertility appears around weeks 3 and 4 after heat stress. Reduced levels of testosterone and sometimes of LH following heat stress are implicated in these adverse effects. There is evidence that boars subjected to high constant temperature (30°C), which have become acclimatised to such, are affected less in terms of sperm output and quality (Cameron and Blackshaw, 1980) than when boars are subject to sudden major increases in temperature from fairly low levels (15 to 30 C) e.g. during the summer months (Antonyuk et al, 1983). There also appears to be large differences between boars in their ability to adapt to exposure to high environmental temperature by minimising temperature rise and avoiding adverse effects on semen quality (Cameron and Blackshaw, 1980). These workers found that boars prone to heat stress show an acute rise in body temperature in response to elevated environmental temperature and this sudden rise has a more adverse effect on semen quality than the length of exposure to the elevated temperature. There appears to be little information available on the reasons for such important between boar differences. This study was carried out to determine rectal temperature responses of boars to varying summer temperature in an intensive pig enterprise in Scotland and to attempt to determine some of the factors associated with ‘high’ and ‘low’ responding boars.


2020 ◽  
Vol 14 (3) ◽  
pp. 155798832092598
Author(s):  
Nathan L. McCray ◽  
Heather A. Young ◽  
Michael S. Irwig ◽  
David Frankfurter ◽  
Arnold M. Schwartz ◽  
...  

A decades-long decline in sperm counts in Western countries has coincided with an increase in obesity rates, prompting study into their association. Few of these studies have incorporated men of color, the sperm health of whom is relatively unknown. The present exploratory study evaluated the association between body mass index (BMI), race, ethnicity, and sperm parameters among a diverse sample of U.S. men attending a Washington, DC physician practice. Semen samples were collected and processed at a single laboratory and sperm concentration, motility, morphology, and count were evaluated according to World Health Organization (WHO) 5th edition criteria. Multivariate models accounted for covariates related to sperm health. The study population ( n = 128) was largely obese (45.3%) or overweight (34.4%), and 36.0% were black or Hispanic. Black men had lower adjusted sperm concentration compared to white men (75.0 million/mL to 107.4 million/mL, p = .01) and were more likely to have oligozoospermia ( p = .01), asthenozoospermia ( p = .004), and low sperm count ( p < .0001). Hispanic men had higher adjusted sperm concentration compared to non-Hispanic men (124.5 million/mL to 62.1 million/mL, p = .007) and were less likely to have teratozoospermia ( p = .001). Obesity and BMI were associated with lower sperm motility and count in crude models only. Given the study’s sample size its findings should be interpreted with caution but align with the limited epidemiological literature to date that has evaluated racial and ethnic differences in semen quality. Heightened clinical research attention is needed to ensure men of color are included in representative numbers in studies of urologic and andrologic health.


2015 ◽  
Vol 4 (3) ◽  
pp. R46-R58 ◽  
Author(s):  
D Santi ◽  
A R M Granata ◽  
M Simoni

IntroductionThe aim of this study is to comprehensively evaluate whether FSH administration to the male partner of infertile couples improves pregnancy rate, spontaneously and/or after assisted reproductive techniques (ART).MethodsMeta-analysis of controlled clinical trials in which FSH was administered for male idiopathic infertility, compared with placebo or no treatment. Randomization was not considered as an inclusion criterion.ResultsWe found 15 controlled clinical studies (614 men treated with FSH and 661 treated with placebo or untreated). Concerning the type of FSH, eight studies used recombinant FSH, whereas seven studies used purified FSH. Nine studies evaluated spontaneous pregnancy rate, resulting in an overall odds ratio (OR) of about 4.5 (CI: 2.17–9.33). Eight studies evaluated pregnancy rate after ART, showing a significant OR of 1.60 (CI: 1.08–2.37). Sub-dividing studies according to the FSH preparations (purified/recombinant), pregnancy rate improvement remained significant for each preparation. Eleven studies considered sperm quality after FSH treatment, finding a significant improvement of sperm concentration (2.66×106/ml, CI: 0.47–4.84), but not of concentration of sperm with progressive motility (1.22×106/ml, CI: −0.07 to 2.52). Three trials evaluated testicular volume, showing a non-significant increase in men treated (1.35 ml, CI: −0.44 to 3.14).ConclusionThe results of controlled clinical trials available in the literature indicate an improvement of pregnancy rate after FSH administration to the male partner of infertile couples, both spontaneously and after ART. However, the heterogeneity of studies, the high risk of bias and the lack of precise criteria to guide FSH administration limit the strength of these results. Future studies should be designed to identify the markers of FSH response which are helpful in the decision-making process. Meanwhile, the use of FSH in the treatment of male infertility should be cautious.


2020 ◽  
Vol 32 (2) ◽  
pp. 137
Author(s):  
Y. Pirosanto ◽  
M. Valera ◽  
A. Molina ◽  
J. Dorado ◽  
S. Demyda-Peyrás

Inbreeding depression, a genetic condition produced by the mating of close-related individuals, has been associated with a reduction of fertility in several species. However, a loss in sperm quality was also associated with age. In horses, the few existing reports have described a tendency of both parameters to produce a negative effect on sperm quality. However, those reports were performed using a subjective evaluation of sperm motility. In the present study, a total of 692 ejaculates from 86 Pure Spanish stallions (PRE), aged between 3 and 22 years, were evaluated using a computer-assisted methodology to determine the effect of inbreeding in four semen parameters: free-gel volume (V), sperm concentration (C, by haemocytometer), and total (TM) and progressive (PM) sperm motility (by Spermvision sperm class analyser; Minitube). The inbreeding coefficient (F) was estimated using 300 000 PRE pedigree records approximately (minimum pedigree depth, eight equivalent complete generations; range, between 1 and 30.1%). Stallion, age, ejaculate, and season of semen collection were the variables included in the statistical model (general linear model), with ejaculate and season being the variables with a major effect (by variance components analysis). Our results showed that sperm concentration (r=−0.18; P&lt;0.0001) and volume (to a lesser extent) were reduced with advancing age, both showing a major decline after 15 years of age. To the contrary, sperm motility was not affected by age of the stallion. We also found a negative correlation between the inbreeding coefficient and ejaculate volume (r=−0.14; P&lt;0.001), with a marked decrease seen when F was between 7 and 20%. Also, a negative correlation was observed in PM (r=−0.08; P&lt;0.05), although to a lower extent. Conversely, C and TM were not affected by inbreeding depression (P&gt;0.05). In conclusion, our results demonstrated that high levels of inbreeding can compromise severely the sperm quality of the PRE stallion, which, subsequently, may have a negative influence on fertility. Ongoing studies using genomic data will help to detect genetic variants associated with stallion semen quality and how it is influenced by inbreeding in specific genomic regions.


2016 ◽  
Vol 28 (10) ◽  
pp. 1518 ◽  
Author(s):  
Urszula Marzec-Wróblewska ◽  
Piotr Kamiński ◽  
Paweł Łakota ◽  
Marek Szymański ◽  
Karolina Wasilow ◽  
...  

We analysed sodium (Na), copper (Cu) and selenium (Se) levels in human semen and glutathione peroxidase activity (GPx) in seminal plasma and examined their relationships with sperm quality. Semen samples were obtained from men (n = 168) undergoing routine infertility evaluation. The study design included two groups based on standard ejaculate parameters: Group I (n = 39) with normal ejaculates (normozoospermia) and Group II (n = 129) with a pathological spermiogram. Se concentration (but not Na or Cu) and GPx activity were significantly higher in normozoospermic males than in those with a pathological spermiogram and also in males with correct sperm motility and normal sperm morphology than in asthenozoospermic and teratozoospermic males. There were significant correlations between sperm motility, Se and GPx, between rapid progressive motility and Cu, between sperm motility and Na, between normal sperm morphology and Se and Cu and between sperm concentration and Cu and GPx. Significant correlations were found between Na and Cu, between Na and Se and between Cu and Se in human semen in relation to alcohol consumption and tobacco use. Na, Cu, Se and GPx are related to sperm characteristics and male fertility and their survey could improve male infertility diagnosis.


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