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

2022 ◽  
Vol 34 (1) ◽  
Author(s):  
Naina Kumar ◽  
Amit Kant Singh

Abstract 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.

Author(s):  
Thea Emily Benson ◽  
Anne Gaml-Sørensen ◽  
Andreas Ernst ◽  
Nis Brix ◽  
Karin Sørig Hougaard ◽  
...  

Bisphenol A (BPA) is considered an endocrine disruptor and has been associated with deleterious effects on spermatogenesis and male fertility. Bisphenol F (BPF) and S (BPS) are structurally similar to BPA, but knowledge of their effects on male fertility remains limited. In this cross–sectional study, we investigated the associations between exposure to BPA, BPF, and BPS and semen quality in 556 men 18–20 years of age from the Fetal Programming of Semen Quality (FEPOS) cohort. A urine sample was collected from each participant for determination of BPA, BPF, and BPS concentrations while a semen sample was collected to determine ejaculate volume, sperm concentration, total sperm count, sperm motility, and sperm morphology. Associations between urinary bisphenol levels (continuous and quartile–divided) and semen characteristics were estimated using a negative binomial regression model adjusting for urine creatinine concentration, alcohol intake, smoking status, body mass index (BMI), fever, sexual abstinence time, maternal pre–pregnancy BMI, and first trimester smoking, and highest parental education during first trimester. We found no associations between urinary bisphenol of semen quality in a sample of young men from the general Danish population.


2019 ◽  
Vol 22 (8) ◽  
pp. 931-938
Author(s):  
M. A. Kleshchev ◽  
V. L. Petukhov ◽  
L. V. Osadchuk

At present great attention is paid to studying genetic regulation of farm animal adaptations to environmental conditions. This problem is very important due to a wide expansion of highly productive cattle breeds created in Europe and North America. However, until the present no investigation of changing semen quality in bulls of imported breeds during their adaptations to environmental conditions of Western Siberia has been conducted. The aim of this study was to investigate semen quality peculiarities and the diversity of morphological sperm abnormalities in bulls of imported and local breeds kept in the environmental conditions of the southern part of Western Siberia. We determined sperm concentration, sperm count, and rate of sperm with progressive motility and percentage of morphologically normal spermatozoa. The rate of sperm abnormalities according to Blome’s classifcation was determined too. It was found that the mean values of sperm concentration, sperm motility and percentage of morphologically normal spermatozoa in the bulls investigated were similar to those in bulls kept in European countries. Inter­breed differences in these parameters were not found. However, bulls of the Red Danish, Angler, and Simmental breeds had a higher percentage of misshapen sperm head and pyriform sperm head than bulls of the Black­White breed. An inter­strain difference in sperm motility in bulls of the Black­White breed was observed. It was found that bulls of Reflection Sovereign 198998 strain had lover sperm motility than bulls of Wis Burke Ideal 1013415 strain. No inter­strain differences in sperm production, percentage of morphologically normal spermatozoa and rate of main sperm abnormalities were found. Thus, it has been found that the environmental conditions of the southern part of Western Siberia do not seriously affect the sperm production, sperm motility or percentage of morphologically normal spermatozoa in bulls. However, the increased rate of misshapen and pyriform sperm heads in the bulls of the foreign breeds points to a need to study sperm DNA fragmentation.


Author(s):  
Kamil Gill ◽  
Joanna Jakubik ◽  
Aleksandra Rosiak-Gill ◽  
Michał Kups ◽  
Mariusz Lukaszuk ◽  
...  

Because the assessment of sperm DNA fragmentation (SDF) plays a key role in male fertility, our study was designed to find the relationships between SDF and standard semen parameters. The receiver operating characteristic (ROC) curve showed that 18% SDF is a prognostic parameter for discriminating between men with normal and abnormal standard semen parameters (n = 667). Men with > 18% SDF had significantly lower quality semen, a higher prevalence of abnormal semen characteristics, and a higher odds ratio for abnormal semen parameters compared to men with ≤ 18% SDF. An ROC analysis provided predictive values for age and semen parameters to distinguish between men with SDF > 18% and men with ≤ 18% SDF. SDF was positively correlated with male age and teratozoospermia index but negatively with sperm concentration, total number of spermatozoa, sperm morphology, progressive motility, and vitality. Our study shows that 18% SDF has a predictive value for distinguishing between men with normal and abnormal semen characteristics. Men with >18% SDF have a higher risk for abnormal semen parameters, while age and obtained semen parameters have a predictive value for SDF. There is a relationship between SDF and conventional sperm characteristics, and thus, SDF can be incorporated into male fertility assessment.


2019 ◽  
Vol 24 (2) ◽  
pp. 30
Author(s):  
Abdul Rahman Jihad Manssor1 ◽  
Zaid Mohammed Mubarak Al–Mahdawi1 ◽  
Azzawi Mustafa Hadi2

L-Carnitine (LC) is highly concentrated in the epididymis and plays a crucial role in sperm metabolism and maturation. They are related to sperm motility and have antioxidant properties. The objective of this review is to summarize the multiple roles played by LC in male reproduction, and to highlight their limitations as well as their benefits in the treatment of male infertility. A variety of studies support the conclusion that LC at total daily amounts of at least 500mg  per day can significantly improve both sperm concentration and total sperm counts among men with astheno – or oligoasthenozoospermia. Although many clinical trials have demonstrated the beneficial effects of LC in selected cases of male infertility. Additional, a well – designed study is necessary to further validate the use of carnitines in the treatment of patients  with male infertility, specifically in men with poor semen  quality .    http://dx.doi.org/10.25130/tjps.24.2019.027   


2021 ◽  
Vol 12 ◽  
Author(s):  
Bijayalaxmi Sahoo ◽  
Ratan K. Choudhary ◽  
Paramajeet Sharma ◽  
Shanti Choudhary ◽  
Mukesh Kumar Gupta

Livestock production contributes to a significant part of the economy in developing countries. Although artificial insemination techniques brought substantial improvements in reproductive efficiency, male infertility remains a leading challenge in livestock. Current strategies for the diagnosis of male infertility largely depend on the evaluation of semen parameters and fail to diagnose idiopathic infertility in most cases. Recent evidences show that spermatozoa contains a suit of RNA population whose profile differs between fertile and infertile males. Studies have also demonstrated the crucial roles of spermatozoal RNA (spRNA) in spermatogenesis, fertilization, and early embryonic development. Thus, the spRNA profile may serve as unique molecular signatures of fertile sperm and may play pivotal roles in the diagnosis and treatment of male fertility. This manuscript provides an update on various spRNA populations, including protein-coding and non-coding RNAs, in livestock species and their potential role in semen quality, particularly sperm motility, freezability, and fertility. The contribution of seminal plasma to the spRNA population is also discussed. Furthermore, we discussed the significance of rare non-coding RNAs (ncRNAs) such as long ncRNAs (lncRNAs) and circular RNAs (circRNAs) in spermatogenic events.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A Pacey

Abstract text Since the very early days of the COVID-19 pandemic, concern has been raised about the possibility of damage to the male reproductive system in those men who are infected with SARS-CoV-2. This was first raised by the early observation (January 2020) that the route of infection was via the Angiotensin Converting Enzyme 2 (ACE-2) receptor present on host cells. ACE-2 was first described in the year 2000 and subsequently shown in 2004 to be selectively expressed in the Leydig cells of the adult testis. This opens up the possibility that although COVID-19 is primarily a respiratory infection, it may also infect the male reproductive system. The authors of several review articles have proposed that male fertility may be theoretically impacted by SARS-CoV-2 in a number of ways. This includes alteration of: (i) testicular architecture; (ii) reproductive hormone profiles (LH/FSH); (iii) spermatogenesis as evidenced by changes to ejaculate quality; (iv) sperm function (e.g., DNA damage); (v) sexual/erectile function; or a combination of all five. Clearly each of these individually may impact on the chance of pregnancy or live birth either in natural or medically assisted reproduction. There is also the possibility that SARS-CoV-2 may be transmitted sexually if sufficient numbers of SARS-CoV-2 are found in semen. Reassuringly, of 14 studies published to date, there is little evidence to suggest that SARS-CoV-2 is present in semen and so the possibility of sexual transmission in patient or donor samples can probably be discounted. However, there is currently an incomplete picture of whether semen quality is affected by SARS-CoV-2 infection as studies are often limited by the fact that no pre-infection control samples are available for direct comparison or they are too short to identify any long-term effects. Nevertheless, the few case-controlled studies published which compare semen quality infected with non-infected (control) individuals suggest that there may be a statistically significant alteration in sperm concentration and motility, although it is not clear whether this is linked to infection by the SARS-CoV-2 virus or simply a consequence of febrile illness and fever (or medication given to combat the infection). There is currently a lack of long-term data on any impact of COVID-19 on male reproductive hormones (although much speculation about the role that testosterone might play in the severity of disease). There are also emerging reports of increased risk of erectile dysfunction in men following SARS-CoV-2. In terms of birth rates, it is simply too early to tell whether these have been affected by the pandemic, given the possibility of lockdown affecting sexual behaviour in fertile couples and IVF clinic closures in infertile couples. In conclusion, although the COVID-19 pandemic has infected over 130 million people worldwide we still know too little about the impact of SARS-CoV-2 on the male reproductive system. Given the incidence of long-COVID, and the asymptomatic nature of the infection for some, it is important to commission and conduct long-term studies which can monitor the reproductive outcomes of young men who have survived a SARS-CoV-2 infection.


2021 ◽  
Vol 48 (2) ◽  
pp. 97-104
Author(s):  
Ahmed T. Alahmar ◽  
Aldo E. Calogero ◽  
Rajender Singh ◽  
Rossella Cannarella ◽  
Pallav Sengupta ◽  
...  

Male infertility has a complex etiopathology, which mostly remains elusive. Although research has claimed that oxidative stress (OS) is the most likely underlying mechanism of idiopathic male infertility, the specific treatment of OS-mediated male infertility requires further investigation. Coenzyme Q10 (CoQ10), a vitamin-like substance, has been found in measurable levels in human semen. It exhibits essential metabolic and antioxidant functions, as well as playing a vital role in mitochondrial bioenergetics. Thus, CoQ10 may be a key player in the maintenance of biological redox balance. CoQ10 concentrations in seminal plasma directly correlate with semen parameters, especially sperm count and sperm motility. Seminal CoQ10 concentrations have been shown to be altered in various male infertility states, such as varicocele, asthenozoospermia, and medical or surgical regimens used to treat male infertility. These observations imply that CoQ10 plays an important physiological role in the maintenance and amelioration of semen quality. The present article thereby aimed to review the possible mechanisms through which CoQ10 plays a role in the regulation of male reproductive function, and to concisely discuss its efficacy as an ameliorative agent in restoring semen parameters in male infertility, as well as its impact on OS markers, sperm DNA fragmentation, pregnancy, and assisted reproductive technology outcomes.


2021 ◽  
Vol 100 (3) ◽  
pp. 223-228
Author(s):  
Aleksey M. Chaulin ◽  
Dmitry V. Duplyakov

Introduction. New advances in the diagnosis and treatment of cardiovascular diseases (CVD), as practice shows, are not able to significantly improve the statistical indicators of morbidity and mortality of CVD. This fact indicates that there are additional factors and mechanisms that are important to consider, both for prevention and for the most optimal management of patients. Recently, the relationship between environmental and lifestyle factors with CVD has been actively studied. However, despite understanding the relationship between environmental factors and various diseases, including CVD, the mechanisms by which specific factors increase or decrease the risk of developing CVD are not yet fully understood, and a number of studies are contradictory. The aim of our work was to generalize existing data on the impact of such critical environmental factors as air pollution and solar insolation on the cardiovascular system, as well as to comprehensively discuss the mechanisms by which these environmental factors can participate in the development and progression of CVD. To achieve our work’s goal, we analyzed modern foreign literature using the PubMed database. Conclusion. According to numerous experimental and clinical studies, air pollution and solar insolation deficiency play an essential role in developing CVD and the aggravation of patients with various CVD (atherosclerosis, hypertension, coronary heart disease, heart failure, myocardial infarction, and stroke). Thus, air pollution and lack of solar insolation can be considered as critical risk factors for CVD. Future research should focus on the study and establishment of specific pathogenetic mechanisms by which environmental factors affect the cardiovascular system’s health to develop effective treatment and prevention measures.


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