Updates in Male Infertility

A special issue of Journal of Clinical Medicine (ISSN 2077-0383). This special issue belongs to the section "Obstetrics & Gynecology".

Deadline for manuscript submissions: closed (31 March 2021) | Viewed by 72124

Special Issue Editor


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Guest Editor
1. Centre for Reproductive Medicine, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
2. Department of Surgical and Clinical Science, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
Interests: IVF; reproductive endocrinology; infertility

Special Issue Information

Dear Colleagues,

According to the World Health Organization (WHO), infertility is a disease defined by the failure to achieve pregnancy after at least 12 months of regular unprotected intercourse. Infertility affects approximately one to six couples and is partly or completely attributable to a male factor in approximately 50% of the cases. Despite this, male infertility is underrecognized and underrepresented as a disease. This is mainly due to the varying definitions of infertility that are commonly used and to the fact that fertility in men is not always evaluated. Males with sperm parameters below the WHO normal values are considered to have a male factor of infertility. Although semen analysis remains the cornerstone to investigate male infertility, this method has limitations, and new biomarkers have recently arisen. If we further take into consideration that several studies have shown a substantial overall decline of sperm values in men in the last decades and the growing body of evidence suggesting that male infertility may be associated with an increased risk of oncologic, metabolic, cardiovascular, and autoimmune diseases, it becomes clear that male infertility is an alarming global health issue that has not been adequately studied.

Prof. Dr. Panagiotis Drakopoulos
Guest Editor

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Keywords

  • Male factor
  • infertility
  • semen analysis
  • sperm

Published Papers (14 papers)

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Editorial

Jump to: Research, Review, Other

3 pages, 174 KiB  
Editorial
Update on Male Infertility
by Erlisa Bardhi and Panagiotis Drakopoulos
J. Clin. Med. 2021, 10(20), 4771; https://doi.org/10.3390/jcm10204771 - 18 Oct 2021
Cited by 4 | Viewed by 1745
Abstract
Infertility, defined as the failure to conceive after one year of regular intercourse without the use of contraception, in women less than 35 years of age remains a unique medical condition, as it involves a couple rather than a single individual [...] Full article
(This article belongs to the Special Issue Updates in Male Infertility)

Research

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9 pages, 391 KiB  
Article
Magnetic-Activated Cell Sorting (MACS): A Useful Sperm-Selection Technique in Cases of High Levels of Sperm DNA Fragmentation
by Alberto Pacheco, Arancha Blanco, Fernando Bronet, María Cruz, Jaime García-Fernández and Juan Antonio García-Velasco
J. Clin. Med. 2020, 9(12), 3976; https://doi.org/10.3390/jcm9123976 - 8 Dec 2020
Cited by 28 | Viewed by 4220
Abstract
Magnetic-activated cell sorting (MACS) can be used to separate apoptotic sperm with high proportions of fragmented DNA from the rest, thus improving the overall quality of the seminal sample. Therefore, the aim of this retrospective study was to investigate the efficiency of the [...] Read more.
Magnetic-activated cell sorting (MACS) can be used to separate apoptotic sperm with high proportions of fragmented DNA from the rest, thus improving the overall quality of the seminal sample. Therefore, the aim of this retrospective study was to investigate the efficiency of the MACS technique to increase reproductive outcomes in patients with high levels of sperm DNA fragmentation (SDF) undergoing intracytoplasmic sperm-injection (ICSI) cycles. In this study, we analyzed a total of 724 assisted-reproduction-technique (ART) cycles that were divided into two groups: the study group (n = 366) in which the MACS selection technique was performed after density-gradient centrifugation (DGC), and the control group (n = 358) in which only DGC was used for sperm selection. Reproductive outcomes were analyzed in both groups according to three different ART procedures: preimplantation genetic testing for aneuploidy (PGT-A), and autologous and oocyte-donation cycles. The MACS group showed significantly lower miscarriage rates in autologous ICSI cycles, higher pregnancy rates in oocyte-donation cycles, and a significant increase in live-birth rates in both autologous and oocyte-donation cycles. Overall, these results suggested that the MACS technique can be effectively used to eliminate sperm with high SDF levels, and therefore may help to improve reproductive outcomes in couples undergoing ART. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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9 pages, 431 KiB  
Article
Low Testosterone and Semen Parameters in Male Partners of Infertile Couples Undergoing IVF with a Total Sperm Count Greater than 5 Million
by Federica Di Guardo, Veerle Vloeberghs, Erlisa Bardhi, Christophe Blockeel, Greta Verheyen, Herman Tournaye and Panagiotis Drakopoulos
J. Clin. Med. 2020, 9(12), 3824; https://doi.org/10.3390/jcm9123824 - 26 Nov 2020
Cited by 12 | Viewed by 3418
Abstract
Low serum testosterone is found in approximately 15% of subfertile men. Although testosterone is essential in spermatogenesis, it is unclear whether low testosterone levels may have a negative impact on the semen parameters of men belonging to infertile couples with a total sperm [...] Read more.
Low serum testosterone is found in approximately 15% of subfertile men. Although testosterone is essential in spermatogenesis, it is unclear whether low testosterone levels may have a negative impact on the semen parameters of men belonging to infertile couples with a total sperm count greater than 5 million. Furthermore, it is debatable whether the initial evaluation of the subfertile male should include an endocrine assessment. This was a retrospective, single-center cohort study conducted at a tertiary fertility clinic. Male partners of infertile couples undergoing in vitro fertilization (IVF), with a total sperm count greater than 5 million, were included. All men provided morning blood samples, and none had been on exogenous testosterone or other relevant medications. Low total testosterone (TT) was defined as <264 ng/dL. Free T was calculated using TT and sex hormone-binding globulin (SHBG) levels (nmol/L) by a constant albumin concentration of 43 g/L. In total, 853 patients were included: 116 had low TT (<264 ng/dL) and 737 had normal TT (≥264 ng/dL). Semen volume, sperm cell count, progressive (A + B) motility and morphology (≥4% strict Kruger) were lower in the low TT group but not significantly different between low and normal TT groups (3.2 ± 1.79 vs. 3.23 ± 1.64, p = 0.87; 76.82 ± 83.18 vs. 67.55 ± 57.70, p = 0.7; 54.89 ± 19.45 vs. 56.25 ± 19.03, p = 0.6; 5.77 ± 3.23 vs. 6.89 ± 3.94, p = 0.23). The percentage of patients with below-reference sperm volume (<1.5 mL), cell count (<15 × 106/mL), motility (A + B) (<32%) and morphology (<4%) was higher in the low TT group but not statistically different compared to the normal TT group. Multivariable regression analysis revealed that low TT and free T levels had no significant effect on the aforementioned semen parameters (coefficient: 3.94, 0.88, 1.37, 0.39; p = 0.53, 0.8, 0.3, 0.2; coefficient: 0.001, 0.06, 0.007, 0.0002; p = 0.73, 0.52, 0.85, 0.98). Despite our robust methodological approach, the presence of biases related to retrospective design cannot be excluded. Our findings highlighted the lack of association between low TT levels and semen parameter alterations in male partners of infertile couples undergoing IVF, with a total sperm count greater than 5 million. However, it is important to emphasize that more patients in the low TT group had subnormal semen parameters, albeit the difference was not statistically significant. Larger, prospective studies are warranted in order to validate these findings, as well as to investigate the existence of a TT threshold below which semen parameters might be negatively affected. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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9 pages, 753 KiB  
Article
Palmitic Acid Targets Human Testicular Peritubular Cells and Causes a Pro-Inflammatory Response
by Artur Mayerhofer, Kim-Gwendolyn Dietrich, Henryk F. Urbanski, Frank-Michael Köhn, Ulrich Pickl, Matthias Trottmann, Paul Kievit and Harald Welter
J. Clin. Med. 2020, 9(8), 2655; https://doi.org/10.3390/jcm9082655 - 17 Aug 2020
Cited by 2 | Viewed by 2321
Abstract
Palmitic acid (PA) is a major fatty acid, derived from diet and endogenous production, which is being linked to inflammation. While such actions of PA at the level of the testis remain difficult to examine, we reasoned that studies in human testicular cells [...] Read more.
Palmitic acid (PA) is a major fatty acid, derived from diet and endogenous production, which is being linked to inflammation. While such actions of PA at the level of the testis remain difficult to examine, we reasoned that studies in human testicular cells may be instructive. Human testicular peritubular cells (HTPCs) can be isolated from men and cultured. They have contractile properties but also produce Interleukin 6 (IL6), express the inflammasome member NLRP3, and via glia cell line derived neurotrophic factor (GDNF), they contribute to the spermatogonial stem cell niche. We found that PA at 100 µM significantly increased the levels of IL6, while NLRP3 or the related Interleukin 1 beta (IL1beta) were not affected. The contractility marker calponin (CNN1) and the growth factor GDNF were likewise not affected. ELISA studies confirmed the stimulatory PA actions on IL6. Hence, PA derived from diet and/or endogenous sources may be able to foster a pro-inflammatory milieu in the testis. A possible link of these results to diet and high fat intake and obesity is indicated by the about 12-fold elevated testicular levels of IL6 in testes of obese rhesus monkeys (n = 3), fed with a Western Style diet. They had elevated 2–5-fold increased body fat and increased circulating triglyceride levels. Further consequences of PA and obesity for testicular functions remain to be evaluated. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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12 pages, 2123 KiB  
Article
The Acrosomal Status of Density Purified Spermatozoa Differentiates Men from Couples in IVF and ICSI Treatment and Is Associated with Fecundity
by Pernille Badsberg Norup, Dorte L. Egeberg Palme, Morten R. Petersen, Katharina M. Main and Kristian Almstrup
J. Clin. Med. 2020, 9(8), 2327; https://doi.org/10.3390/jcm9082327 - 22 Jul 2020
Cited by 1 | Viewed by 1979
Abstract
The acrosome of the spermatozoa is required for fertilization and in the raw ejaculate the percentage of viable acrosome-intact spermatozoa, the acrosomal status, is higher among men with good semen quality. Here we investigated if the acrosomal status of the processed semen preparations [...] Read more.
The acrosome of the spermatozoa is required for fertilization and in the raw ejaculate the percentage of viable acrosome-intact spermatozoa, the acrosomal status, is higher among men with good semen quality. Here we investigated if the acrosomal status of the processed semen preparations used at a fertility clinic can also be informative and whether it is associated with fecundity. The acrosomal status was measured by image cytometry on purified semen samples from couples during in vitro fertilization (IVF) (n = 99) and intracytoplasmic sperm injection (ICSI) (n = 107) treatment. Purified frozen-thawed donor samples were also analyzed (n = 199). In purified semen preparations the acrosomal status was significantly higher among sperm donors (p = 5.3 × 10−8) and men from IVF couples (p = 2.2 × 10−5) when compared to men from ICSI couples. A significant difference was also found between female, male and mixed factor infertility (p = 0.003). No association with lifestyle factors was found. In frozen-thawed donor samples, a significant positive (r = 0.16, p = 0.025) association with the number of pregnancies per sold straw was observed together with an area under the curve of 75.3%, when comparing the top and bottom deciles. Our results indicate that the acrosomal status may be a valuable parameter for personalizing fertility treatments and might be a good predictor of pregnancy success among normozoospermic men. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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19 pages, 1253 KiB  
Article
Sperm Antioxidant Biomarkers and Their Correlation with Clinical Condition and Lifestyle with Regard to Male Reproductive Potential
by Wirginia Krzyściak, Monika Papież, Ewelina Bąk, Eva Morava, Paweł Krzyściak, Anna Ligęzka, Agnieszka Gniadek, Palina Vyhouskaya and Jarosław Janeczko
J. Clin. Med. 2020, 9(6), 1785; https://doi.org/10.3390/jcm9061785 - 8 Jun 2020
Cited by 8 | Viewed by 3747
Abstract
Measurement of sperm oxidative-antioxidant indicators is widely used in the assessment and detection of biochemical causes of male infertility. The main purpose of this study was to identify biomarkers that assist in diagnostics and monitoring of male reproductive potential. We performed the assessment [...] Read more.
Measurement of sperm oxidative-antioxidant indicators is widely used in the assessment and detection of biochemical causes of male infertility. The main purpose of this study was to identify biomarkers that assist in diagnostics and monitoring of male reproductive potential. We performed the assessment of oxidative-antioxidant malondialdehyde (MDA), glutathione (GSH), and total redox antioxidant potential (TRAP) indicators in seminal plasma, seminogram, clinical condition, and lifestyle of people with reproductive problems. The combined assessment of GSH and TRAP as potential biomarkers of male infertility in semen plasma was characterized by the highest total sensitivity and specificity. Furthermore, we provide evidence that male reproductive potential is significantly correlated with basic sperm parameters, sperm cell membrane integrity, their morphology, lifestyle, eating habits, occupation, and mental health. Our results provide evidence on the importance of oxidative stress and defense against free radicals in diagnosing and monitoring men with infertility that are consistent with previously conducted research. We provide an alternative approach on the possibility of interpreting the combination of the biomarkers that can bring benefits to a multi-threaded approach to the diagnosis and treatment of male infertility. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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13 pages, 1043 KiB  
Article
Follicle-Stimulating Hormone Treatment and Male Idiopathic Infertility: Effects on Sperm Parameters and Oxidative Stress Indices according to FSHR c. 2039 A/G and c. -29 G/A Genotypes
by Laura M. Mongioì, Rosita A. Condorelli, Angela Alamo, Rossella Cannarella, Nicolò Musso, Sandro La Vignera and Aldo E. Calogero
J. Clin. Med. 2020, 9(6), 1690; https://doi.org/10.3390/jcm9061690 - 2 Jun 2020
Cited by 4 | Viewed by 2080
Abstract
Scientific evidence shows that the administration of follicle-stimulating hormone (FSH) to infertile patients with normal serum FSH concentrations improves sperm parameters in oligozoospermic men. The aim of this study was to evaluate the effects of highly purified urofollitropin (hpFSH) on conventional and bio-functional [...] Read more.
Scientific evidence shows that the administration of follicle-stimulating hormone (FSH) to infertile patients with normal serum FSH concentrations improves sperm parameters in oligozoospermic men. The aim of this study was to evaluate the effects of highly purified urofollitropin (hpFSH) on conventional and bio-functional sperm parameters and on oxidative stress indices in patients with idiopathic infertility. We also evaluated the response to hpFSH on these parameters in relationship to FSHR c. 2039 A/G and FSHR c. -29 G/A genotypes. A prospective longitudinal study was conducted on 42 patients with idiopathic male infertility, 23 of whom underwent to FSHR c. 2039 A/G and FSHR c. -29 G/A genotyping. Each patient was asked to collect two semen samples before and after administration of 150 IU hpFSH three times a week for 16 weeks. Patients were divided into responders or non-responders based on whether their total sperm count had at least doubled or was less than double at the end of treatment, respectively. Responders showed a significantly higher semen volume, sperm concentration, spermatids, and leukocytes. Non-responders had a significant decrease of the percentage of spermatozoa in early apoptosis after hpFSH administration. Oxidative stress indexes did not differ significantly after FSH administration in both groups. Conventional and bio-functional sperm parameters did not differ in patients with FSHR c. 2039 GG and AA genotypes, and FSHR c. -29 GG genotype both before and after FSH administration. The FSHR c. 2039 and FSHR -29 G/A genotypes and allelic distribution did not differ between responders and non-responders. FSH showed to be capable of ameliorating sperm parameters in about half patients treated, therefore it may be helpful in patients with idiopathic infertility. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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10 pages, 462 KiB  
Article
Use of Biosimilar Follicle-Stimulating Hormone in Asthenozoospermic Infertile Patients: A Multicentric Study
by Maurizio De Rocco Ponce, Carlo Foresta, Rocco Rago, Alessandro Dal Lago, Giancarlo Balercia, Aldo Eugenio Calogero, Sandro La Vignera, Ilaria Cosci, Andrea Di Nisio and Andrea Garolla
J. Clin. Med. 2020, 9(5), 1478; https://doi.org/10.3390/jcm9051478 - 14 May 2020
Cited by 8 | Viewed by 2320
Abstract
There is increasing data in favour of follicle-stimulating hormone (FSH) therapy in patients with oligo-asthenozoospermia and normal-range gonadotropins in order to increase sperm count and above all sperm motility. Some studies showed an improvement in DNA fragmentation and spontaneous pregnancy. Recently, biosimilar FSH [...] Read more.
There is increasing data in favour of follicle-stimulating hormone (FSH) therapy in patients with oligo-asthenozoospermia and normal-range gonadotropins in order to increase sperm count and above all sperm motility. Some studies showed an improvement in DNA fragmentation and spontaneous pregnancy. Recently, biosimilar FSH has been marketed with the same indications. We performed a retrospective multicentric case-control study involving 147 asthenozoospermic patients between 18 and 45 years of age. A total of 97 patients were treated with biosimilar FSH 150 UI three times a week for 3 months, while 50 control subjects received no treatment. Patients were evaluated at baseline and after 3 months with semen analysis including DNA fragmentation, testicular colour Doppler ultrasound, and blood tests. Spontaneous pregnancies were recorded during a further follow-up period of 6 months. Treated patients showed after treatment a statistically significant increase in sperm concentration, total sperm count, and total motile sperm, as well as improved progressive motility and non-progressive motility. DNA fragmentation showed a significant reduction. Conversely, in the control group, no significant change was found. Pregnancy rate was significantly higher in treated patients. These data suggest comparable efficacy of biosimilar FSH in the treatment of male infertility; however, larger studies are needed to confirm our results. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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9 pages, 231 KiB  
Article
Sperm Parameters before and after Swim-Up of a Second Ejaculate after a Short Period of Abstinence
by Claudio Manna, Federica Barbagallo, Raffaella Manzo, Ashraf Rahman, Davide Francomano and Aldo E. Calogero
J. Clin. Med. 2020, 9(4), 1029; https://doi.org/10.3390/jcm9041029 - 5 Apr 2020
Cited by 18 | Viewed by 4802
Abstract
Background: Recent studies have supported the beneficial effects of a short abstinence period on sperm parameters. The aim of this study was to assess sperm motility, morphology and DNA fragmentation before and after swim-up of a second ejaculate obtained after a short abstinence [...] Read more.
Background: Recent studies have supported the beneficial effects of a short abstinence period on sperm parameters. The aim of this study was to assess sperm motility, morphology and DNA fragmentation before and after swim-up of a second ejaculate obtained after a short abstinence period in normozoospermic men and oligo-astheno-teratozoospermic (OAT) patients. Material and methods: Semen analyses and swim-up preparations of two consecutive semen samples (collected within 1 h) were carried out in 30 normozoospermic and 35 OAT patients enrolled in an assisted reproductive technique (ART) program. Results: Compared to the first ejaculate, the second sample showed a higher percentage of spermatozoa with normal form (p < 0.01) and lower percentage of spermatozoa with DNA fragmentation (p < 0.01) in normozoospermic men, whereas a higher percentage of spermatozoa with progressive motility (p < 0.001) and normal morphology (p < 0.0001) was found in OAT patients. Swim-up separation showed a lower DNA fragmentation rate (p < 0.05) in the second ejaculate in normozoospermic men, whereas the second ejaculate of OAT patents showed an increase in normally-shaped spermatozoa (p < 0.01) and lower percentage of spermatozoa with fragmented DNA (p < 0.001) compared to the first one. Conclusions: Swim-up separation of a second ejaculate collected within 1 h might be suggested for ART procedures, especially in OAT patients. Full article
(This article belongs to the Special Issue Updates in Male Infertility)

Review

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13 pages, 271 KiB  
Review
The Effect of Ejaculatory Abstinence Interval on Sperm Parameters and Clinical Outcome of ART. A Systematic Review of the Literature
by Piotr Sokol, Panagiotis Drakopoulos and Nikolaos P. Polyzos
J. Clin. Med. 2021, 10(15), 3213; https://doi.org/10.3390/jcm10153213 - 21 Jul 2021
Cited by 16 | Viewed by 4806
Abstract
Since the publication of the first edition of the WHO (World Health Organization) Laboratory Manual for the examination of Human Semen in 1980, the reference values of sperm parameters have been updated on four occasions. Currently and globally, most of the laboratories analyzing [...] Read more.
Since the publication of the first edition of the WHO (World Health Organization) Laboratory Manual for the examination of Human Semen in 1980, the reference values of sperm parameters have been updated on four occasions. Currently and globally, most of the laboratories analyzing semen samples use the latest, 5th edition of the manual that recommends ejaculatory abstinence from two to seven days before producing the sample for examination. While this standardized interval of time facilitates the interpretation of the results and research, no solid evidence exists to support the WHO-recommended abstinence time for a semen analysis in order to optimize clinical outcomes after assisted reproduction. Most of the studies refer to different clinical outcomes, different groups of patients and different editions of the WHO Laboratory Manual, including heterogeneous intervals of abstinence or sperm parameters. The aim of the current systematic review was to evaluate available evidence correlating ejaculatory abstinence time with clinical outcomes and sperm parameters analyzed according to the last edition of the World Health Organization Laboratory Manual reference values in different male populations. The results from the included studies indicate that WHO abstinence recommendations may need revision, given that a shorter ejaculatory abstinence interval appears to be associated with improved sperm parameters, such as sperm DNA fragmentation, progressive motility or morphology, while evidence suggests a potential increase in embryo euploidy rates and pregnancy outcomes. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
31 pages, 2072 KiB  
Review
Diagnosis and Treatment of Male Infertility-Related Fertilization Failure
by Arantxa Cardona Barberán, Annekatrien Boel, Frauke Vanden Meerschaut, Dominic Stoop and Björn Heindryckx
J. Clin. Med. 2020, 9(12), 3899; https://doi.org/10.3390/jcm9123899 - 1 Dec 2020
Cited by 36 | Viewed by 6996
Abstract
Infertility affects approximately 15% of reproductive-aged couples worldwide, of which up to 30% of the cases are caused by male factors alone. The origin of male infertility is mostly attributed to sperm abnormalities, of which many are caused by genetic defects. The development [...] Read more.
Infertility affects approximately 15% of reproductive-aged couples worldwide, of which up to 30% of the cases are caused by male factors alone. The origin of male infertility is mostly attributed to sperm abnormalities, of which many are caused by genetic defects. The development of intracytoplasmic sperm injection (ICSI) has helped to circumvent most male infertility conditions. However, there is still a challenging group of infertile males whose sperm, although having normal sperm parameters, are unable to activate the oocyte, even after ICSI treatment. While ICSI generally allows fertilization rates of 70 to 80%, total fertilization failure (FF) still occurs in 1 to 3% of ICSI cycles. Phospholipase C zeta (PLCζ) has been demonstrated to be a critical sperm oocyte activating factor (SOAF) and the absence, reduced, or altered forms of PLCζ have been shown to cause male infertility-related FF. The purpose of this review is to (i) summarize the current knowledge on PLCζ as the critical sperm factor for successful fertilization, as well as to discuss the existence of alternative sperm-induced oocyte activation mechanisms, (ii) describe the diagnostic tests available to determine the cause of FF, and (iii) summarize the beneficial effect of assisted oocyte activation (AOA) to overcome FF. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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33 pages, 1516 KiB  
Review
Environmental Impact on Male (In)Fertility via Epigenetic Route
by Matilde Cescon, Rosanna Chianese and Renata S. Tavares
J. Clin. Med. 2020, 9(8), 2520; https://doi.org/10.3390/jcm9082520 - 5 Aug 2020
Cited by 30 | Viewed by 5941
Abstract
In the last 40 years, male reproductive health—which is very sensitive to both environmental exposure and metabolic status—has deteriorated and the poor sperm quality observed has been suggested to affect offspring development and its health in adult life. In this scenario, evidence now [...] Read more.
In the last 40 years, male reproductive health—which is very sensitive to both environmental exposure and metabolic status—has deteriorated and the poor sperm quality observed has been suggested to affect offspring development and its health in adult life. In this scenario, evidence now suggests that epigenetics shapes endocrine functions, linking genetics and environment. During fertilization, spermatozoa share with the oocyte their epigenome, along with their haploid genome, in order to orchestrate embryo development. The epigenetic signature of spermatozoa is the result of a dynamic modulation of the epigenetic marks occurring, firstly, in the testis—during germ cell progression—then, along the epididymis, where spermatozoa still receive molecules, conveyed by epididymosomes. Paternal lifestyle, including nutrition and exposure to hazardous substances, alters the phenotype of the next generations, through the remodeling of a sperm epigenetic blueprint that dynamically reacts to a wide range of environmental and lifestyle stressors. With that in mind, this review will summarize and discuss insights into germline epigenetic plasticity caused by environmental stimuli and diet and how spermatozoa may be carriers of induced epimutations across generations through a mechanism known as paternal transgenerational epigenetic inheritance. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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17 pages, 1008 KiB  
Review
Diet and Nutritional Factors in Male (In)fertility—Underestimated Factors
by Kinga Skoracka, Piotr Eder, Liliana Łykowska-Szuber, Agnieszka Dobrowolska and Iwona Krela-Kaźmierczak
J. Clin. Med. 2020, 9(5), 1400; https://doi.org/10.3390/jcm9051400 - 9 May 2020
Cited by 83 | Viewed by 16302
Abstract
In up to 50% of cases, infertility issues stem solely from the male. According to some data, the quality of human semen has deteriorated by 50%–60% over the last 40 years. A high-fat diet and obesity, resulting from an unhealthy lifestyle, affects the [...] Read more.
In up to 50% of cases, infertility issues stem solely from the male. According to some data, the quality of human semen has deteriorated by 50%–60% over the last 40 years. A high-fat diet and obesity, resulting from an unhealthy lifestyle, affects the structure of spermatozoa, but also the development of offspring and their health in later stages of life. In obese individuals, disorders on the hypothalamic-pituitary-gonadal axis are observed, as well as elevated oestrogen levels with a simultaneous decrease in testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels. Healthy dietary models clearly correlate with better sperm quality and a smaller risk of abnormalities in parameters such as sperm count, sperm concentration and motility, and lower sperm DNA fragmentation. Apart from mineral components such as zinc and selenium, the role of omega-3 fatty acids and antioxidant vitamins should be emphasized, since their action will be primarily based on the minimization of oxidative stress and the inflammation process. Additionally, the incorporation of carnitine supplements and coenzyme Q10 in therapeutic interventions also seems promising. Therefore, it is advisable to have a varied and balanced diet based on vegetables and fruit, fish and seafood, nuts, seeds, whole-grain products, poultry, and low-fat dairy products. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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Other

15 pages, 992 KiB  
Opinion
Infertility: Practical Clinical Issues for Routine Investigation of the Male Partner
by Alberto Ferlin and Carlo Foresta
J. Clin. Med. 2020, 9(6), 1644; https://doi.org/10.3390/jcm9061644 - 30 May 2020
Cited by 15 | Viewed by 8815
Abstract
About one-fifth of couples has fertility problems in Western countries. Male factors are present in about half of them, either alone or in combination with female causes. Therefore, both partners should be evaluated simultaneously. The fertility status and/or specific conditions of each partner [...] Read more.
About one-fifth of couples has fertility problems in Western countries. Male factors are present in about half of them, either alone or in combination with female causes. Therefore, both partners should be evaluated simultaneously. The fertility status and/or specific conditions of each partner influence the clinical and treatment approach. This article summarizes in a practical way when, how, and why the male partner of an infertile couple should be investigated. The available evidence and international guidelines were used, interpreting, discussing, and expanding them from personal decades-long experience in this field. The aim is to delineate the most appropriate clinical approach for the male partner of infertile couples, considering traditional and emerging technologies and laboratory analyses in the context of their clinical significance. Components of the initial evaluation in men without known risk factors for infertility should include at minimum medical history, physical examination, and semen analysis. Semen microbiological examination, endocrine assessment, scrotal ultrasound, and transrectal ultrasound are suggested in most men and are mandatory when specific risk factors for male infertility are known to be present or when the initial screening demonstrated abnormalities. Full examination, including genetic tests, testicular histology, or additional tests on sperm, is clinically oriented and/or suggested after the results of initial investigations. Full article
(This article belongs to the Special Issue Updates in Male Infertility)
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