Decline In Sperm Quality Research Articles

Effect of Uremia on Semen Quality and Reproductive Function in Humans

In this study, we sought to evaluate the effect of uremia on semen quality and reproductive function in humans. For this purpose, 53 end-stage uremic patients were randomly selected. The semen samples were produced by masturbation. Fertility index (FI) was calculated according to the following formula: sperm density (×10(6)/ml) × sperm motility (%) × normal sperm morphology rate (% per 10,000). The semen samples of uremic patients were compared with those of fertile and infertile males. The results show that three patients failed to produce semen. There were no sperm found in four semen samples. The sperm motility, survival rate, sperm density, and normal sperm morphology rate of the remaining 46 patients were found to be significantly lower than those of controls. The uremic patients had the FI of 0.68(2.08) which was obviously lower than that of fertile 7.7(13.51) and infertile 4.13(5.77) males. It was, therefore, concluded that uremia caused a significant decline in sperm quality and reproductive function which resulted in consequential infertility in humans.

Decline of sperm quality and testicular function in male mice during chronic low-dose exposure to microcystin-LR

The effects of chronic low-dose exposure to microcystins were preliminarily studied on sperm quality and testicular function in male mice. Microcystin-LR (MC-LR) was orally administered to male mice at 0, 1, 3.2, and 10 μg/L for 3 and 6 months. Our preliminary study found in three-month group, sperm quality declined at 3.2 and 10 μg/L doses, testosterone dropped at 10 μg/L, levels of LH and FSH increased, and Leydig cells exhibited apoptosis. Similar, but more pronounced, effects were observed in groups treated with MC-LR for 6 months. Compared to control (0 μg/L), the rate of sperm abnormality was higher and testosterone levels were lower following administration of 3.2 and 10 μg/L MC-LR and structural damage to the testis was observed with 10 μg/L dose. Thus, chronic low-dose treatment with MC-LR results in substantial toxicity to male reproduction, causing declines in sperm quality, decreased levels of serum testosterone, and injury to the testis.

Decline in Human Fertility Rates with Male Age: A Consequence of a Decrease in Male Fecundity with Aging?

Background: The objective of this study is to investigate the influence of male age on human fertility, defined as the birth rate for a given population. Methods: Data from the Spanish National Statistics Institute (INE) for the year 2004 from a total of 454,753 newborn infants and sorted by male and female age groups were evaluated. In order to correct the influence of female age-related fertility, a different analysis was performed considering only women under 30 years of age. Results: From a demographic point of view, male fertility started to decline at 35–39 years of age. This decline is constant and follows an exponential pattern (slope –0.11 to –0.12). The trend persisted when the data were adjusted for every 1,000 men in the age group, as well as when only women under the age of 30 were considered. Male fertility showed a 21–23% annual decrease starting at the age of 39. Conclusion: An exponential decrease in human fertility which is independent of the woman’s age was observed with male aging. This decay is probably due to a downfall in male fecundity, closely related to a decline in sperm quality. However, social or behavioral causes for this trend cannot be excluded.

Effects of Ureaplasma urealyticum infection on the male reproductive system in experimental rats

To study the effects of Ureaplasma urealyticum (Uu) infection on the male reproductive system, the mechanism of infertility induced by Uu infection was investigated in experimental rats. Male Sprague-Dowley rats were infected with Uu4 (serotype 4) through repeated natural sexual intercourse for 8 weeks to establish infection. After 8 weeks, the blood samples of the animals were collected and analysed for cytokine production, and the animals were microdissected for the analysis of the reproductive system. Morphological study showed that spermatozoa exhibited curling and breaks in the rats infected at different dosages. Of the infected rats, 27.5% had both soft and hard calculi in the urinary tract, compared with 12% in the control groups. Uu infection resulted in a decline of sperm quality, eventually leading to the death of the spermatozoa. In the infected animals, the serum interleukin 6 and interleukin 8 levels increased significantly (P < 0.05), while tumour necrosis factor-alpha and interferon-gamma showed only modest changes. Our observations showed that Uu infection has an impact on sperm morphology, leading to the death of the spermatozoa. It is plausible that the morphological alterations of spermatozoa induced by Uu infection are one of the possible factors that contribute to male infertility.

Sperm Quality Decline Among Men Below 60 Years of Age Undergoing IVF or ICSI Treatment

Because of changes in the society, couples in Western countries are increasingly delaying reproduction. This is accompanied by unhealthy lifestyles that may be detrimental not only to general health but also to reproductive capacity. It is well known that maternal age has detrimental effects on fertility; the paternal influence on this outcome is largely unknown. This study aims to investigate associations between a paternal age below 60 years, lifestyles, and sperm quality. In a periconceptional prospective cohort study we included 227 men undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment. Age at sperm collection, lifestyles, cause of subfertility, ethnicity, sperm DNA fragmentation index (DFI; as marker of sperm DNA damage), and sperm parameters were determined. Linear regression analyses showed a positive association between a rising age from 26 to 59 years and DFI (P ≤ .01) and an inverse association with ejaculate volume (P ≤ .05). Inverse associations were determined between DFI and all conventional sperm parameters (all P ≤ .01). There were no associations between smoking, alcohol use, body mass index, and DFI and sperm parameters. Dutch men compared to migrants, however, showed a higher DFI (P ≤ .05) independent of lifestyles. We conclude that the trend of delaying fatherhood in men undergoing IVF or ICSI treatment is detrimental to sperm quality.

Application of seminal plasma in sex-sorting and sperm cryopreservation

Substantial dilution of boar semen during processing decreased the concentration of seminal plasma, perhaps contributing to the decline in sperm quality after cryopreservation and sex-sorting. Results of replacing seminal plasma in investigations from many laboratories have been contradictory. Results and discussion here suggest that whereas membrane status can be influenced by seminal plasma, the action of its various components, both positive and negative, is determined in part by the membrane status of the spermatozoa to which it is being exposed. Although progress has been made in identifying components of seminal plasma responsible for its protective effect (notably PSP-I/II spermadhesin for sex-sorted boar spermatozoa), little is known (in any species) regarding how external factors may influence their levels, and their functionality, in seminal plasma. It is noteworthy that seminal plasma is beneficial to post-thaw quality of sex-sorted ram spermatozoa only when added before freezing, not after thawing. Therefore, the action of seminal plasma and its components is dependent on sperm-related factors, in particular the type of processing to which they have been previously exposed. Further research is needed to unravel these biological complexities, and then characterise and synthesise useful proteins within seminal plasma.

Sperm deoxyribonucleic acid fragmentation dynamics in fertile donors

To study the velocity of sperm DNA fragmentation in frozen-thawed sperm samples from male sperm donors of proved fertility. Sperm DNA fragmentation assessment with use of sperm chromatin dispersion methodology after 0, 4, 8, and 24 hours of incubation in IVF medium. Academic biology and reproductive medicine centers. Twenty male fertility donors with proved fertility for a maximum of six births at the reproductive medicine center. None. The velocity of sperm DNA fragmentation between two consecutive incubations was scored. Best adjustment of sperm DNA fragmentation index versus incubation time for linear, logarithmic, or exponential function was tested. Increase of sperm DNA fragmentation through time accounted for a substantial percentage of the overall variation. The highest velocity of sperm DNA fragmentation was observed in the first 4 hours of incubation, decreasing by 50% during the second incubation period and being of the order of 1% in the final experimental period. The tendency to increase in sperm DNA fragmentation is not homogeneous among donors; they may adjust to a logarithmic, linear, or exponential function rendering high values for R(2). Sperm DNA fragmentation occurs rapidly after thawing, and it is an important cause of the rapid decline of sperm quality. Thus, the use of sperm samples as quickly as possible after thawing is highly recommended in clinical practice. Different sperm DNA fragmentation dynamics among individuals were observed.

Dynamics of sperm DNA fragmentation in mammalian species as assessed by the SCD methodology

To determine the differential dynamic increase of sperm cells with fragmented DNA in semen samples from different mammalian species after exposure to a Temperature Excursion Episode (TEE) and 37°C temperature recovering, to simulate insemination. Prospective study in 10 different species. Sperm samples chilled and/or frozen ordinarily, as used for artificial insemination, were incubated at 37°C and sperm DNA fragmentation was assessed at different times (from T0 to T48 h). Species: Human, boar, bull, ram, goat, stallion, donkey, dog, rabbit and mouse. A total of 856 individuals were included in the analysis. Sperm DNA Fragmentation (SDF) was assessed using the Sperm Chromatin Dispersion test (SCD-test; commercial modification Sperm-Halomax®) which was adapted for application in each species by ChromaCell SL. The SDF index commonly found among individuals which were selected for reproductive characteristics was relatively low (5 to 10%), while in those species selected for other characteristics (human, stallion, donkey) exhibited a wider range of SDF. In all species when spermatozoa experience a severe (frozen) or mild (cooled) TEE, SDF is induced and causes the subsequent decline of sperm quality. In all analyzed species, SDF index increases when the biological sperm temperature is resumed. However, the period of time for SDF triggering varies from one species to another and could be detected just at the onset of the biological temperature recovery (human, ram, goat, stallion, rabbit, donkey) or could be delayed for a period of 24–48 h of incubation (bull) or even several days (some boars). In most species, SDF in frozen-thawed samples was detected at the onset of sperm incubation at 37°C, but an increase of SDF was not observed if the fragmentation was immediately assessed after thawing. Interestingly, the general pattern of SDF timing was not totally strict within the same species and differences were observed when different individuals were compared. 1) Alterations of the sperm chromatin by handling for artificial insemination triggers SDF in mammalian species. 2) The dynamics of SDF is species-specific. 3) Within the same species differences were observed in the timing and intensity of SDF when different individuals were compared. 4) The level of SDF tends to be lower in animals which were selected for reproductive characteristics.

Use of a sperm quality analyser on semen of turkey breeders to monitor storage time effects and age-related changes during a reproductive cycle

1. A relatively new instrument known as a Sperm Quality Analyzer® (SQA) offers a rapid assessment of sperm quality and quantity by providing a sperm quality index (SQI). The SQA measures the intensity of sperm activity and motile concentration by determining the number and amplitude of sperm movements per second in a capillary tube as detected through light beam interference. 2. The objectives of the current study were to determine if the SQA could accurately reflect changes in semen quality that occur with prolonged storage of semen and to determine the variation and change in SQI values among individual breeding male turkeys during their semen production cycle. 3. The effect of storage time on SQI values was evaluated by diluting semen with extender and placing the semen on an oscillating shaker at 4°C for 8 h. The SQI values and sperm viability, expressed as % dead sperm, were recorded hourly. The SQI readings declined linearly with increased storage time, while % dead sperm increased linearly with increased semen storage. 4. Semen from 220 individual males was analysed monthly for 9 months. Semen diluted 50-fold with saline had lower SQI values during pre- and post-peak phases of production (months 1, 7, 8, and 9 as compared with months 2 to 6 of semen production). The highest SQI values occurred during months 2 to 6. The largest variation in SQI values occurred during months 1 (CV = 26%) and 9 (CV = 31%) with a CV that averaged 16% for the remaining months. 5. Correlation analysis of SQI values for each bird averaged over 9 months with individual male SQIs for each month showed monthly correlation coefficients that ranged from 0.22 to 0.63. 6. These results indicate that the SQA accurately assessed the decline in sperm quality that occurs with prolonged storage of turkey semen and reflected age-related changes in semen quality and quantity that occurred during a semen production cycle of turkey breeders. In addition, the semen quality rank of some turkey breeders in a population changed with age.

Adaptive female choice for middle-aged mates in a lekking sandfly.

Most theoretical models of age-related mate choice predict that females should prefer older males because they have proven survival ability. An alternative view is that older males represent inferior mates because of negative genetic correlations between early and late fitness components, or because older males have traded off longevity against other fitness components, have accumulated deleterious germ-line mutations, or are less well adapted to current conditions than more recently born individuals. While numerous studies have reported female choice for older males, few have explicitly examined the fitness consequences of such a preference. We present evidence from a lekking sandfly, Lutzomyia longipalpis, showing that choosy females discriminate against older males and gain a fitness benefit from their choice. When permitted free choice from an aggregation consisting of males aged zero to two days (young), four to six days (middle-aged) and eight to ten days (old), females preferentially mated with middle-aged males, but all measures of female reproductive success were independent of male age. In contrast, when a second set of females was randomly assigned single virgin males of known age, the eggs of those paired to old mates exhibited lower hatching success than the eggs of females mated to young or middle-aged males. These results suggest that females avoid mating with older males because they represent poorer quality mates. Age-related differences in male quality may have a genetic basis, but could equally well arise through a phenotypic decline in sperm quality or sperm transfer ability with male age. The lack of evidence of female discrimination against older males from other studies may be because these did not explore the reproductive success of the full age range of males.

P-008. Decline in sperm quality of fertile men in the centre of France

P-008. Decline in sperm quality of fertile men in the centre of France

Falling sperm quality

EDITOR,—Stephen Farrow comments on the quality of the evidence concerning a possible decline in sperm quality,1 focusing attention on our paper published in 1992.2 Farrow also responds to a paper by Peter Bromwich and colleagues, for which we provided the commentary.3 Farrow questions our systematic search of the databases MEDLINE and Index Medicus. A necessary requirement for a valid overview, however, is that the criteria for including articles in the overview (and for excluding them) are explicit and reproducible to avoid selection bias. Several precautions were taken to avoid any undue influence of papers with small numbers of men in them. …

Observations on the decline in sperm quality of Penaeus setiferus under laboratory conditions

The effect of captivity on sperm quality was investigated using Penaeus setiferus sourced in the northwestern Gulf of Mexico. Forty-five males were held indoors in a 3.7-m diameter circular fiberglass tank and evaluated for sperm quality on a weekly basis using the following criteria: (1) spermatophore weight and description of external condition, (2) sperm count, (3) percent live sperm, and (4) percent abnormal sperm. There was no significant decline in sperm quality or quantity until the third week of captivity. At this time, the average percentage of abnormal spermatozoa increased to 68.3%, while the mean number of sperm per spermatophore decreased significantly from between 39.7–54.4 × 10 6 to 16.7 × 10 6. Mean percent live sperm declined to 20.7% at the fifth week in captivity. There was a significant decrease in spermatophore weight between weeks 0–5 and 6–7, with mean spermatophore weights for weeks 6 and 7 of 0.066 and 0.073 g, respectively. These data indicate that there is a decline in sperm quality for P. setiferus held under laboratory conditions.

Recent secular trends in dizygotic twinning rates in Europe.

SummaryIn all European countries for which data exist, there was a maternal-age-specific decline in dizygotic twinning rates during the 1960s. For most of these countries, this decline continued through the 1970s, but in a few it apparently ceased. The causes of the declines and of their abatement are unknown. However, there were declines in sperm quality during the 1960s and 1970s in some parts of the world, including parts of Europe, and it is speculated here that this decline in sperm quality may be related to the decline in dizygotic twinning.

Using the Intel 8741 universal peripheral interface

The correlation between long-term exposure to SRF-EMR and the decline in male fertility is gradually receiving increasing attention from the medical society. While male reproductive organs are often exposed to SRF-EMR, little is currently known about the direct effects of long-term SRF-EMR exposure on the testes and its involvement in the suppression of male reproductive potential. The present study was designed to investigate this issue by using 4G SRF-EMR in rats. A unique exposure model using a 4G smartphone achieved localized exposure to the scrotum of the rats for 6 h each day (the smartphone was kept on active talk mode and received an external call for 1 min over 10 min intervals). Results showed that SRF-EMR exposure for 150 days decreased sperm quality and pup weight, accompanied by testicular injury. However, these adverse effects were not evident in rats exposed to SRF-EMR for 50 days or 100 days. Sequencing analysis and western blotting suggested Spock3 overexpression in the testes of rats exposed to SRF-EMR for 150 days. Inhibition of Spock3 overexpression improved sperm quality decline and alleviated testicular injury and BTB disorder in the exposed rats. Additionally, SRF-EMR exposure suppressed MMP2 activity, while increasing the activity of the MMP14–Spock3 complexes and decreasing MMP14–MMP2 complexes; these results were reversed by Spock3 inhibition. Thus, long-term exposure to 4G SRF-EMR diminished male fertility by directly disrupting the Spock3–MMP2–BTB axis in the testes of adult rats. To our knowledge, this is the first study to show direct toxicity of SRF-EMR on the testes emerging after long-term exposure.