Association between ambient particulate matter exposure and semen quality in fertile men

Background Several studies have suggested adverse effects of particulate matter (PM) exposure on male reproductive health; few have investigated the association between PM exposure and semen quality in a large population of fertile men. Methods We evaluated 14 parameters of semen quality in 1554 fertile men in Nanjing from 2014 to 2016. Individual exposure to particular matter ≤10 μm in diameter (PM10) and ≤ 2.5 μm in diameter (PM2.5) during key periods of sperm development (0-90, 0-9, 10-14, 15-69, and 70-90 days before semen collection) were estimated by inverse distance weighting interpolation. Associations between PM exposure and semen quality were estimated using multivariable linear regression. Results Higher 90-days average PM2.5 was in association with decreased sperm motility (2.21% for total motility, 1.93% for progressive motility per 10 μg/m3 increase, P < 0.001) and four quantitative aspects of sperm motion (curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), and amplitude of lateral head displacement (ALH), P < 0.01). The association between PM2.5 exposure and semen quality were generally stronger for the earlier exposure window (70-90 days prior to ejaculation) than for recent exposure (0-9, 10-14, or 15-69 days). In the subgroup of men who had normal sperm parameters (n = 1019), similar results were obtained. Ninety-days PM10 exposure was associated only with decreased VCL and VAP and was not related to sperm concentration. Conclusions Exposure to PM2.5 adversely affects semen quality, specifically lower sperm motility, in fertile men. Graphical abstract

Aqueous extract of Pedalium murex D. Royen ex L. leafy stem protects against lead induced testicular toxicity in Wistar rats

Objectives Lead exposure seriously impairs male reproductive function. The protective capacity of Pedalium murex leafy stem and fruit aqueous extracts against lead testicular toxicity is evaluated to find herbals drugs able to improve semen quality. Methods Phytochemical screening were performed according to classical methods. Twenty four male rats were divided into four groups of six rats each and received the following treatments via oral route: distilled water; 0.2% lead acetate in drinking water; 0.2% lead acetate in drinking water with 400 mg/kg P. murex aqueous leafy stem extract; 0.2% leaded water with 400 mg/kg P. murex aqueous fruit extract. Treatments were administered for 70 days. Body and reproductive organs weights, sperm parameters and testicular histological sections of each group were examined. Results Flavonoids, tannins, coumarins, alkaloids, and lignans were found in both extracts. Lead intoxication reduced sperm motility and count but increased the percentage of morphologically abnormal sperms. The germinal epithelium of seminiferous tubules histoarchitecture was disorganized by lead. The leafy stem extract was effective in reducing lead induced testicular disruption whereas fruit has not shown any beneficial effect. Conclusions P. murex leafy stem aqueous extract is effective against semen alterations caused by lead.

Impact of environmental factors on human semen quality and male fertility: a narrative review

Background Worldwide rising trend in infertility has been observed in the past few years with male infertility arising as a major problem. One main reason for the rise in male infertility cases is declining semen quality. It was found that any factor that affects semen quality can affect male fertility. There are several modifiable factors affecting semen quality including air pollution, use of pesticides and harmful chemicals, exposure to excessive heat, and can lead to decreased male fertility. Main body The present review focuses on some of these environmental factors that affect semen quality and hence, can cause male infertility. The literature from 2000 till June 2021 was searched from various English peer-reviewed journals and WHO fact sheets using the USA National Library of Medicine (PubMed) database, the regional portal of Virtual Health Library, and Scientific Electronic Library Online. The search terms used were: “Air pollution and male fertility”, “Chemicals and male infertility”, “Heat exposure and infertility”, “heavy metals and male fertility”. Conclusion Adverse environmental factors have a significant impact on semen quality, leading to decreased sperm concentration, total sperm count, motility, viability, and increased abnormal sperm morphology, sperm DNA fragmentation, ultimately causing male infertility. However, all these factors are modifiable and reversible, and hence, by mere changing of lifestyle, many of these risk factors can be avoided.

Consumption of Sugar-Sweetened or Artificially Sweetened Beverages and Semen Quality in Young Men: A Cross-Sectional Study

Background: Existing literature suggests that frequent consumption of sugar-sweetened drinks may be associated with lower semen quality. Studies performed in mice suggest a dose-response relationship between intake of saccharin or aspartame, two artificial sweeteners, and sperm and testis function. Methods: A cross-sectional study based on data from The Fetal Programming of Semen Quality (FEPOS) Cohort, including 1047 young men (mean age = 19 years) was performed. Each male participant completed an online questionnaire on health, health behavior and diet, and provided a semen sample. The associations between consumption of sugar-sweetened or artificially sweetened beverages (moderate ≥ 3 days/week; infrequent < 3 days/week) and semen quality were analyzed using a multivariable, negative, binomial regression model. Results: Sugar-sweetened or artificially sweetened beverage consumption was not strongly associated with either semen volume, sperm concentration, total sperm count or total motility in young men. The proportion of morphologically normal sperm was 11% lower (0.89 (95% CI 0.76, 1.04)) for moderate (≥3 days/week) consumption of artificially sweetened beverages relative to infrequent (<3 days/week). Conclusion: Consumption of sugar-sweetened or artificially sweetened beverages, at the levels present in this study had limited effect on the measured markers of semen quality in young men.

Comparison of ICSI and Conventional IVF in Non-Male Factor Patients with Less Than Four Oocytes

Background: We aimed to analyse our clinical results for a particular subgroup of patients with poor ovarian response (POR) in order to clarify if lower number of oocytes is a drawback for proceeding to C-IVFMaterials and methods: In this retrospective study, patient files of all couples (#1733) who underwent oocyte retrieval between January 2017 and December 2019 were reviewed and 191 cases diagnosed with non-male factor infertility in which ≤3 cumulus-oocyte-complexes available for fertilisation were analysed. Exclusion criteria were: woman age>42, patients with a history of previous ART trial, prenatal genetic testing cycles and couples undergoing total cryopreservation for any indication. Three groups were constructed depending on the method of fertilisation and on semen quality as follows: IVF non-male factor (Group 1,n=77); ICSI non-male factor (Group 2, n=65); ICSI male factor- ICSI/MF n=49 according to WHO reference values. Main outcome parameters were: fertilisation rate, implantation rate and live birth rate. Results: Fertilisation rate per collected COC was significantly higher in group 1 compared to the other two groups (85,68%, 72,58%, 73,33% respectively, p=0,004). FR per inseminated oocyte also tended to be higher in group 1 but not reaching a statistically significant level. Both techniques yielded similar implantation rates (20,42%, 28,49%, 23,33% respectively, p=0,407) and live birth rates (26,8%, 30,6%, 31,1% respectively, p=0.643).Conclusions: In the presence of normal semen parameters, low egg number is not an indication to perform ICSI. The choice of fertilisation method should be based primarily on semen quality, in combination with the patient’s previous history regardless of the ovarian reserve.

A synthesis of senescence predictions for indeterminate growth, and support from multiple tests in wild lake trout

Senescence—the deterioration of functionality with age—varies widely across taxa in pattern and rate. Insights into why and how this variation occurs are hindered by the predominance of laboratory-focused research on short-lived model species with determinate growth. We synthesize evolutionary theories of senescence, highlight key information gaps and clarify predictions for species with low mortality and variable degrees of indeterminate growth. Lake trout are an ideal species to evaluate predictions in the wild. We monitored individual males from two populations (1976–2017) longitudinally for changes in adult mortality (actuarial senescence) and body condition (proxy for energy balance). A cross-sectional approach (2017) compared young (ages 4–10 years) and old (18–37 years) adults for (i) phenotypic performance in body condition, and semen quality—which is related to fertility under sperm competition (reproductive senescence)—and (ii) relative telomere length (potential proxy for cellular senescence). Adult growth in these particular populations is constrained by a simplified foodweb, and our data support predictions of negligible senescence when maximum size is only slightly larger than maturation size. Negative senescence (aka reverse senescence) may occur in other lake trout populations where diet shifts allow maximum sizes to greatly exceed maturation size.