12 Natural Male Enhancement Foods For A Bigger Manhood Health And Fitness

The semen analysis (SA) is an important component in the initial clinical evaluation of the male and his reproductive health. Clinicians should include a reproductive history during initial evaluation of the male for fertility. Both the female and male are equal stakeholders in both diagnosis and treatment. However, the high variability of SA parameters make them difficult to use in the determination of interventions for male reproduction.5 Other outcome metrics with similar challenges include other types of sperm tests and ART outcomes such as fertilization, implantation, and pregnancy loss rates. Male infertility is typically diagnosed by one or more factors that may include abnormal semen quality or sperm functional parameters; anatomical, endocrine, genetic, functional, or immunological abnormalities of the male reproductive system (including chronic illness); or sexual conditions (e.g., erectile dysfunction) incompatible with the ability to deposit semen in the vagina. This article focuses on the histology of testicular tissue samples, the male reproductive structure, factors affecting male infertility, strategies available to find genes involved in infertility, existing therapeutic methods for male infertility, and sperm recovery in infertile men. Sperm aneuploidy may account, in part, for the increased rate of sex chromosome defects in children conceived by ICSI, the higher rate of pregnancy loss after testicular sperm extraction with ICSI for treatment of nonobstructive azoospermia and recurrent pregnancy loss in some couples with unexplained infertility120. Microdeletions in the Yq region, also known as the azoospermia factor region, are present in 8-12% of men with azoospermia and 3-7% of men with oligozoospermia, making it the most common genetic cause of male infertility. A key diagnostic method in male infertility diagnostics, especially where oligozoospermia and azoospermia are concerned, is genetic testing.

• Maternal smoking during pregnancy and lactation could potentially cause harmful effects on male offspring fertility.
• Knowledge of the anatomical relations of the male genital tract is crucial for effective performance of surgical procedures.
• Regular marijuana smoking (more than once weekly within the last 3 months) was found to lower sperm concentration and total sperm count amongst young men, and this effect was further exacerbated when marijuana was used in combination with other recreational drugs .
• The male reproductive excretory ducts also have their distinct microbiota, which can influence male reproductive health 50,52.
• Certain factors, such as cigarette smoking and alcohol intake are likely to exert an additive effect, whilst other factors may pose a threat when exposed along with other environmental and occupational factors.
• Approximately 100 to 300 million sperm are produced each day, whereas women typically ovulate only one oocyte per month.
• The majority of (but not all) genes on the Y-chromosome encode proteins involved in testis determination or spermatogenesis.

Other key hormones include inhibin B and Mullerian inhibiting substance (MIS) hormone, both produced by the Sertoli cells in the testes. Testosterone can be converted in the periphery to a more active form, dihydrotestosterone via 5-alpha-reductase, or estradiol via aromatase. Knowledge of the anatomical relations of the male genital tract is crucial for effective performance of surgical procedures. Therefore, it is necessary to introduce new key factors and diagnostic and noninvasive biomarkers. During spermatogenesis, germ cells face major epigenetic reprogramming that includes the organization of sex-specific designs in the sperm, which substitution of histone to protamine is one of them.148–150 Numerous experiments have revealed altered epigenetic function in sperm from men with oligozoospermia and oligoasthenoteratozoospermia. Spermatogenesis is one of the most crucial stages in male fertility.36–39 The slightest deviation from the natural course of spermatogenesis can lead to infertility in men. However, the wide range of male infertility in meta-analysis studies may not reflect the prevalence of this complication in all parts of the world because of reasons such as the lack of rigorous statistical methods that include bias, heterogeneity in data collection, and cultural constraints. Clinicians should counsel couples desiring conception after vasectomy that surgical reconstruction, surgical sperm retrieval, or both reconstruction and simultaneous sperm retrieval for cryopreservation are viable options. These treatments include oral sympathomimetics with alkalinization of urine and/or instillation of sperm wash media into the bladder via urethral catheter before climax. It is important to differentiate dry ejaculate (aspermia) from azoospermia, where an antegrade ejaculate is present but lacks spermatozoa. Penile vibratory stimulation, electroejaculation, surgical sperm retrieval, or sympathomimetic agents may be utilized depending on the cause of the ejaculatory dysfunction, the patient’s condition, and surgeon’s experience. Most targeted monoclonal antibody therapies appear to have only minimal effects on sperm counts and male fertility potential, but the data on these agents are limited.267 Certain chemotherapeutic drugs are toxic to stem cells and can cause prolonged azoospermia. These therapies can have dramatic effects on a male’s ability to father children, and this is particularly important with adolescents and young males hoping to preserve their fertility. Surgical SRR in this small study was 64% in the males who received FSH versus 33% in the no-treatment group.248

3. Biomarkers for Identifying Microbial Dysbiosis in Male Infertility

Key mechanisms linking microbial dysbiosis to infertility include inflammation, oxidative stress, and sperm structural deterioration. However, there does not appear to be evidence suggesting that cryopreserved testicular sperm negatively influences the pregnancy and live birth outcomes after TESE-ICSI (205). Men with obstructive azoospermia can be treated with epididymal or testicular sperm extraction, although epididymal extraction is typically less invasive (199). Another prospective study of men with idiopathic oligozoospermia and normal FSH levels reported significantly improved sperm retrieval rates, fertilization, and pregnancy rates post-TESE-ICSI in men treated with FSH versus untreated controls (187). Hakonsen et al conducted an uncontrolled study in 43 men, with obesity reporting that men losing the most weight (17.2–25.4% of body weight) had an increase in sperm count, semen volume, and testosterone when compared with baseline (119). As described previously, ejaculatory duct obstruction refers to block at the interface of the prostate and seminal vesicles, preventing semen from entering the urethra with ejaculation. A detailed discussion of treatment options is beyond the scope of this chapter. Finally, as mentioned above, an MRI of the pituitary gland is indicated to rule out a tumor in the setting of hyperprolactinemia or in patients with severe secondary hypogonadism (low LH/FSH, low testosterone). If present, the seminal vesicles may appear dilated, and assessment of fluid after aspiration with ultrasound guidance will show copious sperm under the microscope. While specific research on the relationship between gut microbiota and male infertility is limited, existing studies provide valuable insights. Recent studies have drawn attention to the correlation between gut microbiota dysbiosis and male infertility, suggesting its potential significance in clinical practice 78,79,80. Identifying these imbalances can guide precision medicine approaches, offering tailored treatments for male infertility . In summary, microbial dysbiosis in the male reproductive tract correlates with male infertility. Dysbiosis in the male reproductive tract microbiota is considered a factor in male infertility. Consistent with a multifactorial etiology of male infertility, axonemal and outer dense fiber defects can be found in individuals with asthenozoospermia resulting from ciliapathies, such as primary ciliary dyskinesia and Kartagener's syndrome. In many fertility clinics today, clinical evaluation of the male may be superficial and limited to an assessment of the presence or absence of sperm in the ejaculate before advancing to treatment with an assisted reproductive technology (these are discussed in a later section). Nevertheless, there are other diseases of the female reproductive tract in which genetic studies are slowly beginning to make inroads. Likewise, the ticking of the female biological clock and premature menopause have resulted in unplanned infertility for otherwise fertile couples. For infertile males with ejaculatory duct obstruction, clinicians may consider transurethral resection of ejaculatory ducts (TURED) and/or surgical sperm extraction. Clinicians should counsel males with vasal or epididymal obstructive azoospermia that microsurgical reconstruction may be successful in returning sperm to the ejaculate. Limited data exist comparing outcomes for the various procedures available to obtain sperm from males with ejaculatory dysfunction. Couple infertility may be due to male factors, female factors, or a combination of male and female factors. The AUA conducted a thorough peer review process to ensure that the document was reviewed by experts in the diagnosis and treatment of male infertility. Evaluation of males with secondary infertility should include a focus on conditions or exposures that have developed or occurred after initiation of the earlier pregnancy(ies). In addition, male infertility may occasionally be the presenting manifestation of an underlying life-threatening condition.4 Failure to identify diseases such as testicular cancer or pituitary tumors may have serious consequences, including, in rare cases, death. Although many couples can achieve a pregnancy with– intrauterine insemination (IUI) and assisted reproductive technologies (ART) (in vitro fertilization IVF with or without intracytoplasmic sperm injection ICSI), evaluation of the male is important to most appropriately direct therapy.

• This figure, updated from Matzuk and Lamb1, reveals the genes known today that influence testicular and sperm function in the mouse.
• Absence of RSPO1 or WNT4 in XX mice causes female-to-male sex reversal, whereas stabilization of β-catenin causes XY mice to develop male-to-female sex reversal, confirming their roles in this pathway49–51.
• The use of testicular sperm in nonazoospermic males with elevated DFI provides an alternative option for fertility treatment.191 Testicular sperm retrieval procedures, such as testicular sperm aspiration (TESA) or testicular sperm extraction (TESE), may offer viable sperm with lower DFI, potentially improving the chances of successful assisted reproduction.138
• Guideline for the prevention, diagnosis and treatment of infertility
• Direct exposure of spermatozoa to alcohol (at concentrations corresponding to that of serum after moderate and heavy drinking) was found to be harmful to sperm motility and morphology in a dose-dependent manner .
• If the fasting morning total testosterone level is low (103 a repeat measurement of total and free testosterone (or bioavailable testosterone) as well as determination of serum LH, estradiol, and prolactin levels should be obtained.
• If the obstruction is at the level of the seminal vesicles / prostate or the ejaculatory duct, the semen volume will likely be low as well.

In the epididymis, the sperm takes about twelve days to mature and develop motility. The tail eventually joins with the vas deferens, providing an outlet for mature sperms to ejaculate. These spermatozoa are still immotile and are released into the tubules to travel to the epididymis for maturation. The most primitive spermatocytes are found peripherally in the seminiferous tubules and mature by migrating towards the lumen. It is unclear whether a genetically tractable model that recapitulates PCOS can be created, given that humans are usually monoovulatory, whereas mice are polyovulatory. Consistent with an increased risk of ovarian cancer in women with endometriosis, mice with both of these genetic changes develop and die from uterine endometrial ovarian cancer. Advanced knowledge of these pathways may aid in diagnosis and treatment of implantation failure in women. These progesterone receptor–Cre mice helped to define essential roles of BMP2, chicken ovalbumin upstream promoter transcription factor II, steroid receptor coactivator 2 (SRC2), PTEN and mitogen-inducible gene-6 in uterine biology and cancer and the ovulatory function of peroxisome proliferator–activated receptor-γ. Hence, loss of testicular function results in damaged or underdeveloped Leydig or Sertoli cells that cannot respond to stimuli to maintain reproductive function. Primary hypogonadism (also referred to as hypergonadotropic hypogonadism) results from a gonadal failure to produce adequate testosterone or spermatogenesis despite high LH and FSH levels. FSH and testosterone can stimulate Sertoli cells to release androgen-binding protein (ABP), which provides testosterone to germ cells during spermatogenesis. The clinician should discuss with the patient what he can do to modify or prevent exposure to risk factors of infertility. The absence of validated outcomes predictive of male fertility is another weakness in determining cause and effect between a particular risk factor and infertility. In addition, data suggest that infertile males have a higher risk of incident disease (new cases diagnosed).44 The conflicting results for associations between CCI and semen abnormalities (three studies were positive, and one showed no association) may be due to different choices and the amount of confounding variables.58 Cazzaniga et al. controlled for age, testicular volume, FSH level, varicocele, and other semen abnormalities, which is a relatively large number of variables. In this clinical setting, male partners should be evaluated by male reproductive experts, and clinicians should consider karyotype and sperm DNA fragmentation testing. As CFTR regulates anion transport and fluid secretion in the excurrent ducts, it is thought that dysregulation of proper fluid dynamics leads to obstruction and/or atrophy in the epididymis and vas deferens during embryogenesis.126, 127 Indeed, some males with otherwise idiopathic genital tract obstruction are found to harbor mutations in the CFTR gene. Thus, knowledge of which region(s) of AZF is microdeleted aids in clinical decision-making, as males with complete deletions of AZFa and/or AZFb should not undergo TESE for ART. Sperm have not been retrieved by micro-TESE in males with complete AZFa, AZFb, AZFab, or AZFabc microdeletions. Because the functions of both the Na+/H+ exchanger and the CatSpers are required for sperm motility, these channels are potential targets for designing male contraceptives98. Similarly, the causes of benign conditions such as uterine fibroids, endometriosis and polycystic ovarian syndrome (PCOS), which cause substantial morbidity and infertility in a large number of women of child-bearing age, are genetically intractable at this time, making screening tests difficult. Problems such as endometriosis, polycystic ovarian disease, recurrent pregnancy loss, ovulatory defects, sperm deficiencies (count, motility, morphology and function), fertilization failure, embryo loss and implantation defects are poorly understood, although research is slowly progressing. A balanced and diverse microbiota within the male genital system is essential for optimal reproductive health . Predominant bacterial genera in the male reproductive tract include Corynebacterium, Streptococcus, and Staphylococcus 61,62. The male reproductive system, once perceived as largely sterile, is now recognized as a complex mosaic of microbial communities. The male reproductive excretory ducts also have their distinct microbiota, which can influence male reproductive health 50,52. Research indicates that male factors contribute to 20-30% of infertility cases. In this episode, we explore the anatomy of the male reproductive system, factors influencing fertility, and both practical and advanced interventions that can enhance reproductive health. With advancements further advancements in genetics, especially next-generation sequencing, it is expected that new causes of infertility will be discovered, continually improving our approaches to combat this frequent condition. Different causes of infertility, including ovarian disorders, fallopian tube disorders, pelvic diseases, and uterine abnormalities, require an individualized approach to diagnostics and treatment. Advancements in minimally invasive procedures in the treatment of infertility have resulted in a lesser need for “classical” surgical procedures which carry a higher risk of complications (16).

Defects in the development of the genital tract

These age-related changes inevitably lead to deterioration of sperm quality and quantity. However, APA has not been as well-defined, with studies commonly defining it to be between 35 and 50 years of age or categorising it into age ranges of 5 years . Advanced maternal age is defined as the age of 35 years, beyond which there is significantly increased risks of adverse reproductive outcome for women . Antibiotic treatment may improve sperm quality and prevent testicular damage and complications, but its effects on natural conception are not yet elucidated (96, 97). Inflammation of the epididymis from the infection can induce infertility through sperm tract obstruction (91). Treatment with orchidopexy is therefore recommended between 6 and 18 months of age to conserve spermatogenesis (85) and hormone production, and decrease the risk of testicular tumors (86). Hypothyroidism, stress, elevated estrogen levels, chronic renal failure, and chest wall injuries can increase prolactin levels. Tumors near the hypothalamus or pituitary that interfere with the secretion of dopamine or its delivery to the hypothalamus (e.g., craniopharyngiomas) infiltrative diseases (e.g., sarcoidosis, hemochromatosis, TB), and malignant tumors that arise within or near the sella or metastasize to these areas can also elevate prolactin levels.235 For persistently elevated prolactin levels above the normal value without an exogenous etiology, pituitary MRI is indicated. One reviewer independently assessed risk of bias (ROB) for individual studies. Members of the AUA Male Infertility Guideline Amendment Panel met with ECRI research analysts in July 2023 to review the recommendation statements from the 2020 Guideline. The Male Infertility Amendment Panel was created in 2023 by the AUA to review new literature and provide updates herein. This is not harmful from an overall health perspective but is a potential cause for male factor infertility. Certain causes of male factor infertility such as congenital bilateral absence of the vasa deferens (CBAVD) and varicocele are established by physical examination. However, as noted above, nearly 50% of infertility involves male factor causes. Finally, assisted reproductive technologies such as intrauterine insemination (IUI) and IVF can overcome many potential causes of idiopathic infertility.

• In addition, male infertility may occasionally be the presenting manifestation of an underlying life-threatening condition.4 Failure to identify diseases such as testicular cancer or pituitary tumors may have serious consequences, including, in rare cases, death.
• Analysis of semen parameters of healthy men over a wide age range (22–80 years) showed that semen volume and sperm motility declined gradually and continuously with age without a specific age threshold .
• Testis-expressed gene 11 (TEX11) is an X-linked gene encoding a protein crucial for male germ cell meiotic DNA recombination and chromosomal synapsis.
• The classical phenotype is that of a tall male with small, firm testes and gynaecomastia (59), however the phenotype may vary from a fully virilized male to one with androgen deficiency.
• Sperm concentration in male smokers was reported to be typically 13–17% lower than that of non-smokers .
• Finally, assisted reproductive technologies such as intrauterine insemination (IUI) and IVF can overcome many potential causes of idiopathic infertility.
• The underlying mechanisms are, however, unclear and hypothesized to include damage to the germinal epithelium, ischemia, or immune dysfunction, with cell damage from increased ROS (95).
• Given the significant contribution of male factors to infertility in couples, as well as high levels of unknown factors in male infertility, a lack of understanding of the underlying mechanisms seems to be one of the most important challenges facing this problem.

In conclusion, paternal preconception health advise may improve lifestyle factors, with a positive effect on sperm parameters. Despite observed improvements in semen parameters, the effects on pregnancy and live birth outcomes are limited (122, 180). Utilization of ART is dependent on factors such as the availability of reproductive technology, the health system of the country, and funding from state or insurers. Testing for karyotype and Y chromosome microdeletions are recommend for all infertile men with suspected NOA or severe oligozoospermia (112). By contrast, serum FSH is often elevated in testicular failure (165), but LH and testosterone secretion may be preserved. For ART, only a small number of motile sperm are required for the procedure.311 Since ARTs are only moderately effective, a couple may need to undergo several cycles of IVF treatment in order to achieve a pregnancy. The recovery of spermatogenesis following radiotherapy and/or chemotherapy depends on the survival of spermatogonial stem cells in the testis. As previously discussed, gonadotoxic therapies can cause a marked decline in sperm production as a result of acute injury to testicular germ cells. Gonadal dysfunction is a significant long-term consequence of cancer therapy.249, 304 This is particularly important for adolescents and young adult cancer patients who are at risk of developing infertility following cancer therapy. Studies on the health and genetic integrity of children fathered by males exposed to chemotherapy and/or radiotherapy have generally been reassuring. This dilation increases the amount of blood that can enter the penis and induces the endothelial cells in the penile arterial walls to also secrete NO and perpetuate the vasodilation. If a mass is detected, the cancer diagnosis is confirmed by biopsy of the cells. However, some forms of prostate cancer grow very slowly and thus may not ever require treatment. It excretes an alkaline, milky fluid to the passing seminal fluid—now called semen—that is critical to first coagulate and then decoagulate the semen following ejaculation. The paired seminal vesicles are glands that contribute approximately 60 percent of the semen volume. The purpose of the micro-TESE is to identify the nuclear regions of testicular sperm production based on the size and appearance seminiferous tubules with the aid of a microscope, in which spermatozoa can be recovered from open seminiferous tubules, the whole process being visible under the microscope. For infertile men, sperm must be recovered directly from the testicles or epididymis. Following some of the most up-to-date and important strategies for treating infertility with a specific cause, are mentioned. Until now, however, genetic risk factors identified with this technique have shown poor association. Exome sequencing is another field that has revolutionized the study of a variety of disorders, including infertility. While prolactin levels generally parallel tumor size, milder elevations can be found with prolactinomas as well as with other pituitary or parasellar tumors or infiltrative processes.230, 231 When evaluating prolactin levels, the clinician should be aware of assay discrepancies, which result in false values. Males with decreased libido and/or impotence and/or testosterone deficiency accompanied by a low/low-normal LH level warrant measurement of serum prolactin to investigate for hyperprolactinemia. Long-acting exogenous testosterone administration provides negative feedback to the hypothalamus and pituitary gland, which can result in inhibition of gonadotropin secretion. For males with aspermia, clinicians may perform surgical sperm extraction or induced ejaculation (sympathomimetics, vibratory stimulation or electroejaculation) depending on the patient’s condition and clinician’s experience. For those couples where the male has NOA and sperm are frozen and survive freeze-thaw, ART is possible with those sperm. In males undergoing surgical sperm retrieval by a clinician, intracytoplasmic sperm injection may be performed with fresh or cryopreserved sperm. In this report by Kirby et al., the ORs for pregnancy and live birth were 1.76-fold higher for males treated with varicocelectomy prior to ART.177 Disruption of these intimate communication pathways blocks the development of fertilizable female gametes. Thecal cells, which surround the follicle, produce androgens that are converted by the granulosa cells into estrogens—hormones needed for the normal function of the ovary, secondary sex organs, the menstrual cycle and a variety of other actions in diverse tissues ranging from brain to bone to the gastrointestinal system. Thus, this condition typically suggests defective hypothalamus or pituitary function, whereas hypergonadotropic hypogonadism is often indicative of end-organ failure (that is, ovarian or testicular dysfunction including defects in the gonadotropin receptors). Communication between each cellular compartment within the testis (seminiferous tubules, interstitial cells and blood vessels, as well as between individual cell types (germ cells, Sertoli cells, peritubular myoid cells, Leydig cells and macrophages)) play essential parts in mitosis, meiosis and differentiated function. Androgens (including testosterone) have a key role in the development of the male genital tract but are not the only signaling pathways involved. Identification of conditions for which there is no treatment will spare couples the distress of attempting ineffective therapies and allow them to consider options, such as donor sperm or adoption, if appropriate. Identification and treatment of reversible conditions may improve the male’s fertility and allow for conception through intercourse or through techniques, such as IUI or IVF, when those approaches would otherwise not be possible. Additionally, the ingredients in these gummies can help boost testosterone levels, which are crucial for maintaining a healthy libido and sexual function. Each component in the formula serves a specific role, contributing to improved smooth muscle functionality, enhanced blood circulation, and increased testosterone levels. BTB, Blood-Testis Barrier; PGC, primary germ cell; GnRH, gonadotropic releasing hormone; AZF, azoospermic factor; CBAVD, congenital bilateral absence of the vas deferens; CFTR, cystic fibrosis transmembrane regulator; SNP, single-nucleotide polymorphism; GWAS, genome-wide association studies; HCG, human chorionic gonadotropin; OA, obstructive azoospermia; NOA, non-obstructive azoospermia; TESE, testicular sperm extraction; ICSI, intracytoplasmic sperm injection; SSR, sperm recovery rate. With the advances in technology and the introduction of new methods and approaches, it is hoped that many of the causes of male infertility will soon be identified and treated. This can cause emotional, economic, and physical stress for couples, so sperm retrieval requires the use of predictive factors, and this will not be possible unless you have in-depth knowledge of all the steps that can lead to Infertility in men. Conversely, urine samples obtained from infertile men demonstrated an increased presence of Anaerococcus. Comparing samples from fertile and infertile individuals, rectum samples from infertile men showed variations in the abundance of Anaerococcus, while displaying an elevated abundance of Lachnospiraceae, Collinsella, and Coprococcus. In contrast, a direct correlation was observed between a decreased abundance of Lactobacillus and abnormal sperm morphology. Although the study found a suggestive trend of impaired fertility status in the offspring of overweight mothers, it was not statistically significant . Increasing maternal BMI had a negative relationship with the offspring’s inhibin B levels. Increased oxidative stress impairs sperm motility, DNA integrity, and sperm–oocyte interaction . Increased production of leptin by the white adipose tissue decreases testosterone production. Furthermore, a male evaluation may inform some couples of treatment options other than IUI and ART. At this time there is no substitute for the information provided by semen analysis testing conducted in a specialized andrology laboratory for a comprehensive evaluation of male fertility.33 Semen parameter values falling above or below the lower limit do not by themselves predict either fertility or infertility.29 In the interpretation of SA, the clinician should remember that semen parameters are highly variable biological measures and may vary substantially from test to test. Increased seminal levels of ROS in smokers expose spermatozoa to oxidative stress, consequently impairing sperm function and ultimately compromising male fertility (reviewed in ). Grasping the impact of microbial factors on male infertility is essential for both accurate diagnosis and effective management of this intricate condition. Genetic testing can pinpoint rare genetic disorders or chromosomal abnormalities contributing to male infertility. Implementing microbial-based interventions in male infertility introduces ethical and safety challenges, encompassing informed consent, protection of personal health data and transparency in treatment utilization.

Medical Professionals

• The prenatal production of testicular anti-Mullerian hormone (AMH), acting through its receptor AMHR2, induces the regression of the Müllerian duct, whereas testosterone drives the development of these Wolffian duct derivatives.
• The central strand of the flagellum, the axial filament, is formed from one centriole inside the maturing sperm cell during the final stages of spermatogenesis.
• Infertility is due in whole or in part to the male in approximately one-half of all infertile couples.
• Plasma levels of ACTH and corticosterone were elevated, whilst FSH, LH, and testosterone were decreased.
• LH and prolactin are indicated for patients with hypogonadism (i.e. low circulating testosterone levels).
• Specifically, from the lumens of the seminiferous tubules, sperm move into the straight tubules (or tubuli recti), and from there into a fine meshwork of tubules called the rete testes.

Future research is needed to determine unidentified factors causative in idiopathic male factor infertility. Underlying genetic predisposition, exposure to environmental factors, and adverse lifestyle behaviors contribute to the etiopathogenesis of testicular dysfunction. A meta-analysis of men with NOA due to KS suggested successful spermatozoa retrieval in up to 50% of cases, with nearly 50% pregnancy and live birth rates after TESE-ICSI, independent of male age, testes volume, and reproductive endocrine profile (202). However, genetic disorders such as AZFa/AZFb microdeletions or XX male syndrome are contraindications to TESE due to their incompatibility with spermatogenesis. A meta-analysis of 11 RCTs reported significant improvement in sperm concentration, motility, and spontaneous pregnancy rate in men with idiopathic infertility and OAT on antiestrogen therapy compared with controls (190). Males with deletions of AZFc and smaller partial deletions of AZFa and/or AZFb should be counseled that sperm may or may not be found with TESE.124, 125 They should be counseled regarding these risks and the need for ART with preimplantation genetic testing for aneuploidies. If the sample is azoospermic, then another pellet analysis should be performed. If no sperm are present, a second SA should be performed at least one to two weeks later. The relationship of testosterone, LH, FSH, and prolactin helps to identify the clinical condition. Maternal smoking during pregnancy and lactation could potentially cause harmful effects on male offspring fertility. Contributing factors leading to these effects in male smokers include the presence of nicotine and its metabolite, cotinine, benzo(a)pyrene, as well as cadmium levels . Besides its association with impaired male fertility, tobacco smoking is also responsible for increases in DNA damage, aneuploidies, and mutations in sperm . Available evidence pertaining to the potential adverse effects of these lifestyle factors on male fertility vary in strength. The present article reviews the available evidence examining the potential effects of lifestyle factors on male reproductive health. Elevated scrotal temperatures lead to spermatogenic arrest, germ cell apoptosis, oxidative stress, and sperm DNA damage . Prolonged hours of sitting or exposure to radiant heat, varicocele, and cryptorchidism can all lead to testicular heat stress . Male consumption of coffee had a negative relationship with ICSI fertilisation rate, but did not seem to affect implantation, pregnancy, and miscarriage rates . Intraoperative photographs of a micro-TESE in a patient with nonobstructive azoospermia (NOA). A recent meta-analysis reported that mean levels of total serum testosterone were reduced in men with NOA 6 months after TESE, with a recovery time ranging between 18 and 26 months (206). It is interesting to consider whether cryopreservation negatively impacts the reproductive potential of sperm. Currently, there are no clinical factors or biochemical tests that can reliably predict sperm retrieval in men with NOA prior to surgery.

Figure 1. Causes of male and female infertility (created with Biorender.com).

A small sample is taken from an accessible area and evaluated for histopathology.170–172 Due to the uncertainty of sperm retrieval and failure of sperm retrieval, egg retrieval will be unnecessary. This process involves controlled ovarian stimulation to increase the maturation of several oocytes, egg harvest through follicle aspiration, sperm recovery, laboratory inoculation, and embryo transfer and culture. C) Artificial fertilization in which the egg and sperm are fertilized outside the body and the resulting embryo is transferred into the uterus. Moreover the presence of pollutants and sulfur dioxide in the air changes the natural shape of sperm and also has a detrimental effect on sperm motility.120–123 Erectile dysfunction, known as impotence, early ejaculation and inability to ejaculate are examples of intercourse problems.110,111 Cryptorchism can be treated with human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH), but surgical intervention is also necessary to preserve testicular function and prevent malignant alterations (15). Treatment of infertility is very individual as it primarily focuses on the specific causes behind it. One of the novel methods for early and precise infertility diagnosis is nanotechnology, which utilizes biosensors to detect new biomarkers. Women with reciprocal translocations are exposed to a higher risk of infertility.

• Incomplete masculinization due to a range of endocrine and steroid receptor defects can cause virilization failure (male pseudohermaphrodism) leading to a spectrum of female-to-male phenotypes depending upon the point of cessation of virilization.
• The Human Microbiome Project, initiated in 2007, aims to consolidate genetic data from diverse human microbiomes to understand the relationship between microbiome alterations and various diseases 45,46.
• The process of spermatogenesis begins with mitosis of the diploid spermatogonia (Figure 27.5).
• Testicular biopsy is almost always performed in association with surgical sperm retrieval (see section on ‘Surgical sperm retrieval techniques’).
• During ejaculation, sperm exit the tail of the epididymis and are pushed by smooth muscle contraction to the ductus deferens (also called the vas deferens).
• To effectively address infertility, health policies need to recognize that infertility is a disease that can often be prevented, thereby mitigating the need for costly and poorly accessible treatments.
• This leads to changes in Sertoli cells and the blood–testis barrier, which ultimately causes spermatogenesis to be suppressed.

These include supporting cells called sustentacular cells, as well as five types of developing sperm cells called germ cells. They are composed of developing sperm cells surrounding a lumen, the hollow center of the tubule, where formed sperm are released into the duct system of the testis. Evidence is limited on whether — or how much — herbs or supplements might help increase male fertility. Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition. Conceiving a child during this period can substantially increase the risk of genetic mutations in the offspring. The genomic damage induced by these treatments is germ cell stage specific. Findings were inconclusive with respect to spontaneous and ART pregnancy rates.243 Additionally, the cost-to-benefit ratio of this treatment is questionable. However, there were no significant associations between levels of ASA and pregnancy outcomes in these patients. Indirect testing is advantageous when the patient sample is oligozoospermic or asthenozoospermic (alone or in combination), when there is obstructive azoospermia, or when a sample cannot be immediately assayed. For analysis of antibodies in semen, there are two versions of these tests - direct and indirect; for example, the direct IB test uses washed patient and control spermatozoa that are incubated with small beads with antibodies specific for IgG or IgA attached and are prepared in the laboratory. Therefore, clinicians may consider using testicular sperm as opposed to ejaculated sperm for IVF/ICSI. Further, available data are inadequate to conclude that this assay should be routinely performed in the initial evaluation of the infertile male. Although not FDA-approved for use in males, SERMs such as clomiphene or tamoxifen are often prescribed in infertile males who have normal serum testosterone levels with the therapeutic aim of improving semen parameters and fertility outcomes. Some males despite cessation of testosterone therapy never fully recover their sperm production thus remain either infertile or sub-fertile and may require future fertility treatments.226, 227 Although ART does not correct the underlying condition(s) causing male infertility and allows pregnancy for males where natural pregnancy has not previously occurred, these techniques involve limited medical risk to the female partner. While the available studies are of low quality, fertilization, pregnancy, and live birth rates were similar for epididymal and testicular derived sperm in males with azoospermia due to obstruction.185 However, epididymal sperm retrieval should be avoided if future microsurgical reconstruction (i.e., vasovasostomy or epididymovasostomy) might be pursued due to the risk of epididymal scarring and obstruction.186, 187 This will provide a more comprehensive insight into the molecular mechanisms underpinning male infertility 118,119,121. The horizon holds promise for personalized medicine in the realm of male infertility management. The exploration of the microbiome’s association with male infertility, while comprehensive, still presents significant limitations and offers ample opportunities for further research. To identify the precise prebiotic formulations, doses, and durations of therapy that are most successful in reestablishing a healthy microbial balance in male infertility, more study is required. This latest finding has sparked even greater concern over the reasons behind the apparent decline in the sperm count of Western men. They reported a significant decline of 50–60% in sperm counts amongst men from North America, Europe, Australia and New Zealand . In the most recent report, Levine’s group performed a systematic review and meta-regression analysis of the current trends in sperm counts. There has been increasing evidence on the global decline in human sperm quality over the past few decades , , , . Environmental, occupational, and modifiable lifestyle factors may contribute to this decline. We offer specialised courses that blend scientific research with Traditional Chinese Medicine (TCM), empowering acupuncturists to improve patient outcomes and lead in reproductive health. Founded by Irina Szmelskyj, The Fertility Education Foundation advances fertility acupuncture through evidence-based education. Whether you’re trying to conceive or simply want to understand your reproductive health better, we’re here to help. Multiple studies have researched the complex relationship between obesity and female infertility and have noted a linear decline in spontaneous pregnancy occurrence with the rise of body mass index (BMI). Increased levels of exogenous testosterone, resulting from AAS use, exert a negative feedback on the HPG axis causing reversible suppression of spermatogenesis, testicular atrophy, and infertility. Recently, viruses such as human papilloma virus (HPV) has been found in semen of men with male infertility (100); however, further good quality studies are needed to define its true clinical impact and association with sperm quality (101). As with other genetic causes of male infertility, men with structural chromosomal abnormalities should be offered preconception genetic counselling and the option for preimplantation genetic diagnosis, prior to using their ejaculated or testicular sperm during ART (69). The seminal vesicles produce fructose, which provides the energy for sperm motility. The ductus deferens delivers the sperm to ejaculatory duct by joining with the seminal vesicle duct near the prostate. When ejaculation occurs, smooth muscle contractions of the epididymis pushes sperm into the ductus deferens (vas deferens), which sits in the spermatic cord. The midpiece contains abundant mitochondria to provide energy for the flagellum or tail of the sperm. It is important to note that in this method, the function and expression of candidate genes in model animals and their effect on infertility have already been proven, and given the foregoing, it is possible to predict the gene involved in human infertility. A) The candidate gene approach; Identification of genes that lead to impaired fertility in model animals (mostly mice), and assuming that their function is maintained during evolution, these genes are selected and their roles and effects in human infertility are studied. Men exposed to hazardous substances in their workplace, including solvents, insecticides, adhesives, silicones and radiation, exposure to these and similar substances can lead to infertility.82,112,113 Exposure to radiation can lead to reduced sperm production, and exposure to high doses can lead to complete infertility. Testosterone injections are mainly used to improve testicular growth, normalize testosterone concentration, and stimulate the development of secondary sexual traits.96–98 Similarly, the pituitary’s inability to produce sufficient amounts of luteinizing hormone and follicular stimulating hormone results in a failure to stimulate the testes and to produce testosterone and sperm.99,100 Patients with pituitary deficiency require long-term hormonal therapy, which can lead to complications such as diabetes mellitus, heart disease and bone defects. As mentioned, infertility can have a feminine or masculine origin, with the male factor only present in one third of cases.

Male Reproductive Physiology

The most common genetic cause is Klinefelter’s disease (a phenotypic male with 47, XYY), and other causes are listed in Table 1. The causes of this are multifactorial and can include genetic abnormalities, medications (chemotherapy, testosterone, radiation), infections, and idiopathic causes. Nonobstructive azoospermia is a failure of the testis to produce sperm. OS markers, including ROS concentrations, lipid peroxidation, and antioxidant enzyme function, can provide insights into the oxidative state of seminal fluid and its association with dysbiosis 103,108,109. Technologies like PacBio and Oxford Nanopore sequencing produce extended DNA reads, resolving complex microbial communities and enhancing taxonomic and functional assignments . This allows for a comprehensive assessment of microbial community composition and potential functionality 76,102,103,104,105. To address this challenge, the majority of clinical trials addressing male fertility and infertility utilize surrogate outcome metrics, the most common being the SA. Assessment of tests and treatments for the male is challenging due to inconsistent endpoints and the observation that many of these endpoints are dependent upon and measured from the female partner. Infertility should be evaluated after 6 months of attempted conception when the female partner is 35 years of age or older. Thus, an appropriate male evaluation may allow the couple to better understand the basis and implications of their infertility. Defects in androgen action, such as androgen insensitivity syndrome, result in a female phenotype despite male genotype due to an inability of the body's tissues to respond to testosterone. Secondary hypogonadism results from a disruption in the hypothalamic-pituitary axis where low GnRH, LH or FSH leads to low testosterone and spermatogenesis. Other tests include semen analysis, which establishes fertility status and function of the seminiferous tubules, epididymis, and accessory sex glands. Functional cells of the male reproductive system primarily consist of Leydig and Sertoli cells found in the testes. The major male androgen is testosterone, which is produced from Leydig cells in the testes. The process that begins with spermatogonia and concludes with the production of sperm is called spermatogenesis. They extend physically around the germ cells from the peripheral basement membrane of the seminiferous tubules to the lumen. Sertoli cells secrete signaling molecules that promote sperm production and can control whether germ cells live or die. Surrounding all stages of the developing sperm cells are elongate, branching Sertoli cells. Translation of the newer advances discussed above will be slower but will eventually move from the laboratory to the clinical arena to provide more therapeutic options for males. Finally, gene therapy approaches targeting the process of spermatogenesis, are advantageous because of the continuous production of sperm throughout the adult lifespan. Qualitative but not quantitative spermatogenesis has been achieved in vitro culminating in live offspring in rodents. Today, this knowledge is used clinically to counsel patients about their chances for successful ART.345, 346 As many of these “infertility” genes are expressed in select other tissues or even broadly throughout the body, infertility may be the “canary in the coal mine” that portends an increased likelihood of other comorbidities. Clinicians should inform patients undergoing a retroperitoneal lymph node dissection of the risk of aspermia or retrograde ejaculation. Eleven of the studies were rated as moderate quality, while four were rated as low quality. The durations of follow-up were two years (eight studies), two to five years (four studies) and six or more years (three studies). Clinicians may inform patients that a semen analysis should be performed at least 12 months (and preferably 24 months) after completion of gonadotoxic therapies. For IUI, insemination with a minimum of 3 to 5 million motile sperm in the ejaculate is needed.309, 310 Below this motile sperm count, the success rate of the technique decreases. Spermatogonia divide to produce primary and secondary spermatocytes, then spermatids, which finally produce formed sperm. Spermatogonia are the stem cells of the testis, which means that they are still able to differentiate into a variety of different cell types throughout adulthood. Sertoli cells are a type of supporting cell called a sustentacular cell, or sustentocyte, that are typically found in epithelial tissue. When analyzing data for the rates of azoospermia, rates were highest within the first 12 months after completion of therapy and lowest at a time point between 2 to 6 years, with the majority of studies demonstrating the nadir in azoospermia rates at a timepoint between 2 to 3 years following treatment completion. As such, males should be encouraged to bank multiple semen specimens and the sperm bank should divide the specimen into adequate aliquots in order to prepare for multiple attempts at assisted reproduction. This implies that during and for a defined period of time after exposure to radiation and/or chemotherapy (depending on the susceptible germ cell), males can produce an increased proportion of genetically abnormal spermatozoa. One of the major concerns regarding the effects of gonadotoxic therapies in males wishing to father children is the induction of mutations in developing testicular germ cells.287 Studies have clearly demonstrated that radiation and chemotherapy can alter the genomic integrity of testicular germ cells. PRDM1 has a multifunctional role in repressing somatic cell gene expression and allowing PGC proliferation and migration. For example, soon after implantation in the mouse embryo, a bone morphogenetic protein (BMP) pathway induces the proliferation and specification of PGC precursors from which PR domain–containing 1 with ZNF domain (PRDM1; also known as BLIMP1) becomes the first exclusive marker of the PGC lineage2,3. Thus, the formation of primordial germ cells (PCGs) at the base of the yolk sac, their tortuous journey along the hindgut to the genital ridge, and the proliferation and migration of the somatic cells and germ cells in the bipotential gonad are independent of which sex chromosomes the fetus harbors. The first step in the establishment of the fertility of a higher organism is the determination of its sexual identity, which is ultimately determined by the sex chromosomes. However, having the Y chromosome defines differentiation into the male phenotype and the male reproductive system. These cells are characterized by their relation to germ cells or primitive spermatogonia. They promote spermatogenesis, which begins at the periphery of the tubules. Together, these hormones form the hypothalamic-pituitary-gonadal axis that promotes and maintains sexual development and function in the male. Seminal ROS are released physiologically by leucocytes and as by-products of intracellular metabolic pathways and during adenosine triphosphate (ATP) production from the sperm mitochondria. Semen analysis parameters are subject to marked biological variation, with standard deviations comparable to mean levels (34). WHO reference range for semen analysis with examples of main abnormalities related to semen analysis It reflects the production of spermatozoa in the testes, the patency of the duct system and the glandular secretory activity (33). Testosterone and inhibin B have negative feedback effects at pituitary and hypothalamic levels. The function of Sertoli cells is to nourish and develop sperm through the stages of spermatogenesis and their mechanical support.22–24 These cells produce two types of inhibin and activin hormone that have positive and negative feedback to FSH.25–27 In addition, Sertoli cells control the stages of sperm release into the lumen, phagocytosis of the degraded germ cells and additional cytoplasm resulting from sperm release. These statistics show a lack of understanding of the mechanisms involved in male infertility. Despite numerous efforts by researchers to identify the underlying causes of male infertility, about 70% of cases remain unknown. According to the latest WHO statistics, approximately 50–80 million people worldwide sufer from infertility, and male factors are responsible for approximately 20–30% of all infertility cases. These treatments are performed under the direction of reproductive endocrinology / infertility, a sub-specialty of obstetrics/gynecology. However, novel genetic studies have demonstrated a much wider range of contributors, which were previously unknown, allowing for more precise diagnostics. In 25% of those cases, the etiology cannot be determined, which is called idiopathic infertility. The definition of infertility implies a specific timeframe, while sterility is a permanent state of infertility (1). The condition of infertility is defined as the lack of natural conception in a heterosexual couple after 12 months of regular unprotected sexual relations. In women under 35 years of age, infertility is considered present after 12 months of attempting to conceive. Age of the female partner is the single most important factor when predicting the chances of conception for a couple. Most couples achieve a pregnancy in the first 3 to 6 months of attempted conception, with 75% of couples achieving a pregnancy after 6 months of trying.10-13 In general, after one year of attempting to conceive, approximately 85% of couples will have achieved a pregnancy. All attempts to measure some aspect of sperm function lessens the confounder effect of a maternal outcome, yet all are also subject to their own limitations. Amongst couples with successful IVF/gamete intra-fallopian transfer (GIFT) outcomes, male caffeine consumption had no effect on fertilisation, pregnancy or live-birth rates. Most studies have not found an association between moderate caffeine intake and male fertility. Therefore, couples must be counselled with equal emphasis on the contribution of APA and advanced maternal age as being potential risk factors of negative pregnancy outcomes and impaired offspring health. Accumulation of ROS in male germ cells throughout the course of ageing leads to oxidative stress and damage to sperm DNA. The fact that both normal physiological processes and environmental factors could be held responsible for the effects of ageing on the male reproductive system adds to its complexity . Increased aromatization of testosterone to estrogen may have direct negative testicular impact, as estrogen receptors are present in most cell types of the human testes, including Leydig and Sertoli cells (123). Radioiodine therapy for thyroid disease may cause testicular damage and abnormal spermatogenesis (116); however, these adverse effects are usually dose- and time-dependent, with improvements in sperm parameters after cessation of therapy. Alkylating agents such as cyclophosphamide and immunosuppressants, particularly sirolimus, are toxic to germ cells (113); sperm cryopreservation is normally recommended beforehand, and contraception is advised during treatment due to potential teratogenicity. The adverse effects can range from direct testicular spermatogenic impairment and antiandrogenic effects to ejaculatory/sexual dysfunction. Amongst former smokers, every additional year following the male partner’s smoking cessation reduced the risk of ART failure by 4%, particularly between clinical pregnancy and live birth . Moreover, male smoking could even influence the clinical pregnancy rate per intrauterine insemination (IUI) cycle . Maternal cigarette smoke exposure during the gestation and weaning period was shown to cause diminished germ cell population, germ cell DNA damage, and defective sperm in the male offspring . Pre-conception paternal smoking presents an increased risk of several morbidities in the offspring, which could perhaps be mediated via epigenetic modifications transmitted through spermatozoa. Once puberty occurs, the hypothalamus releases GnRH in a pulsatile fashion every one to two hours to maintain amounts of FSH, LH and plasma testosterone, all of which regulate each other to maintain hormonal balance. Before puberty, the levels of androgens and gonadotropins typically remain low and constant. Inhibin serves as the negative feedback control that Sertoli cells exert on the hypothalamic-pituitary system to decrease FSH release. Testosterone can also exert some effect on Sertoli cells, found in the periphery of the seminiferous tubules of testes. The enzyme 17-beta-hydroxysteroid dehydrogenase completes the conversion of androstenedione to testosterone.

• The Male Infertility Panel was created in 2017 by the American Urological Association Education and Research, Inc. (AUAER) and ASRM.
• Proper semen analysis takes time and very specialized training by an andrologist, so ideally this test is performed at a lab with experience.
• Alternatively, agents targeting the Sertoli cell, such as gamendazole179, and germ cell adhesion180 show excellent specificity and efficacy in animal models, again providing new approaches to male contraception with potential for human translation.
• OT; oligoteratozoospermia; OAT, oligoasthenoteratozoospermia; Morph., morphology defects; Mot., motility defects.
• You are encouraged to confirm any information obtained from or through this site with other sources, and review all information regarding any medical condition or treatment with your physician.#onlinepharmacy #healthcare #viagra #erectiledysfunction
• In adulthood, Sertoli cells are meiotically inactive.28–30 Sertoli cell division terminates concurrently with the first meiotic division of the germ cells, giving rise to tight junctions between these cells, known as the Blood-Testis Barrier (BTB) (Figure 2).31,32 The epithelium of seminiferous tubules is divided into two (functionally different) regions by BTB.
• Clinical assessment of Y chromosome microdeletions provides prognostic information for individuals concerned about transmission to the male offspring.
• More advanced testing such as sperm DNA fragmentation can also be done but is beyond the scope of this chapter.
• Despite numerous efforts by researchers to identify the underlying causes of male infertility, about 70% of cases remain unknown.

For microbial-based therapies for male infertility to be effectively implemented, a myriad of factors must be considered. Therefore, there is a pressing need for large-scale prospective studies to ascertain the microbiome’s role as a causative factor in male infertility . A significant number of studies have not delved into the impact of the microbiome on clinical fertility outcomes in infertile males. Case series of males with NOA and clinical varicoceles have been reported. No demonstrable benefit of varicocele repair was observed in pregnancy or bulk seminal parameters with the exception of a possible small numerical effect on progressive sperm motility that is unlikely to be clinically important.178 Clinicians should not recommend varicocelectomy for males with non-palpable varicoceles detected solely by imaging. Infertility may be caused by a number of different factors, in either the male or female reproductive systems. Infertility is a disease of the male or female reproductive system defined by the failure to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse. In closing, the genomic revolution has placed us at the forefront of vastly improving our diagnostic abilities to define precise etiologies, co-morbidities, and eventually (perhaps) develop medically-based treatments for infertile males to improve not only their fertility potential, but also their overall health. As the mechanisms of action of these genetic, genomic, epigenetic, transcriptomic, proteomic, metabolomic defects are defined, we will have further defined the etiologies of the majority of causes of male infertility. Normal sperm counts are typically greater than 15 million/mL and motility greater than 40%. A sperm sample is collected and examined microscopically for count, motility, and shape. Some testosterone is also bound to albumin, which serves as a transporter. A majority of testosterone is bound to plasma proteins, particularly sex-hormone-binding globulins (SHBGs), which serve as storage. The semen then passes the bulbourethral glands or Cowper’s glands, which release a thick fluid that lubricates the urethral opening and clears the urethra of any urine residue. This gene transfer can introduce new functionalities, influencing the overall dynamics of the microbiome. They can infect and lyse specific bacterial cells, thereby regulating bacterial populations and maintaining microbial balance . Bacteria, a significant component of the microbiome, fulfill several functions that are essential for overall well-being. Further research is essential to understand the complex interactions between human microbiota and reproductive health and potential therapeutic interventions 54,55. In conclusion, the microbiota in various body sites, including gut and reproductive tracts, profoundly impacts human health and reproductive outcomes 33,53. Opioids are known to cause secondary hypogonadism by inhibiting kisspeptin-neurokinin B-dynorphin (KNDy) neuronal activity (153), but may also have direct testicular effects due to presence of endogenous opioid receptors through the testis (154). These negative effects of androgen abuse on the HPT axis are fully but slowly reversible (apart from testicular volume and SHBG) 6 to 18 months after ceasing androgen intake in the majority of men (152). A meta-analysis including 5865 patients showed a negative association between smoking and semen parameters (142), with a pronounced negative effect on moderate and heavy smokers. In reality, exposure to these risk factors does not occur individually but simultaneously (140, 141). Donkin et al (125) demonstrated that the expression level of specific mitochondrial RNAs, and small nuclear RNA (snRNA) fragments, was altered in the spermatozoa of men with obesity. This perspective led to a limited understanding of the microbiota composition of the male reproductive tract. Historically, the absence of microbial growth in tests on samples from the male reproductive tract, termed “culture-negative”, was seen as an indication of the absence of bacterial infection. While there has been extensive research on microbiota across various anatomical regions, the study of microbiota in the male reproductive system remains relatively limited. Additionally, interactions between the microbiota and dietary components, such as polyphenols found in plant-derived foods, can impact the gut microbiota’s composition and function, further influencing human health . The Human Microbiome Project, initiated in 2007, aims to consolidate genetic data from diverse human microbiomes to understand the relationship between microbiome alterations and various diseases 45,46. After detailing the mechanisms and diagnostic methods, the manuscript delves into current treatment strategies and concludes with recommendations for future research directions. For instance, a comprehensive study spanning from 1973 to 2011 observed a significant decline of 50–60% in sperm counts in Western nations . Clinicians should not recommend sperm DNA fragmentation analysis in the initial evaluation of the infertile couple. In addition, formal genetic counseling should also be considered for a discussion of carrier status, genetic hereditability, and preimplantation genetic diagnosis for any couples who test positive for a mutation. In cases where the male patient has a mutation in the CFTR gene and the partner is also a carrier, then there is a risk of an affected offspring (25% if both partners are carriers, and up to 50% if the male has mutations in both alleles with a female partner who is a carrier). Thus, “5T” analysis along with the CFTR mutation analysis is indicated to identify the etiology for vasal agenesis and to consider for preimplantation diagnosis if the female partner is a carrier. In a study of 198 males, 34% of males with idiopathic obstruction had a CFTR mutation; 5 males had 2 mutations (including poly T), and 14 males had one mutation.128 Obstruction that limits or prevents the seminal vesicle contribution will lead to acidic semen (pH 166 However, scrotal ultrasound can be used to confirm the presence of varicocele before varicocele repair and following treatment to determine treatment success based on shared decision-making. In these infrequent cases, color doppler ultrasound may be used to examine spermatic cord veins. In the rare cases where testis biopsy is done primarily for diagnostic purposes, sperm cryopreservation from the sample should be attempted if ART is an option. Infertility may occur due to male, female or unexplained factors. The male reproductive system is a complex and well-coordinated biological network responsible for sperm production, hormone regulation, and the delivery of semen during sexual intercourse. Newer research techniques, such as next generation sequencing (whole exome and whole genome sequencing) and “-omic” technologies have been applied to better identify underlying defects that may explain infertility in males. Given the aforementioned incidence of long-term azoospermia after gonadotoxic therapies, some males with interest in starting a family or expanding their family size will be faced with a decision regarding how to accomplish this. Clinicians should obtain a post-orgasmic urinalysis for males with aspermia after retroperitoneal lymph node dissection and reduced volume ejaculate who are interested in fertility. One comprehensive meta-analysis reviewed 15 trials and described impacts of FSH administration versus placebo or no treatment on semen parameters and pregnancy rates. Exogenous FSH may be used as an adjunct for treatment of HH in order to initiate and maintain spermatogenesis with good results. As such, any possible limited benefits of SERM administration, particularly in the patient population with idiopathic infertility, are small and, therefore, outweighed by the distinct advantages offered by other forms of medically-assisted reproduction (e.g., IVF), which include higher pregnancy rates and efficiencies with respect to the earlier timeframe of conception. Hyperprolactinemia is a well-established cause of secondary hypogonadism and can lead to infertility, decreased libido, sexual dysfunction, and gynecomastia. Thus, although the genetic causes of human male infertility and transmission of defective genetic traits remain concerns for urologists treating infertile men with ICSI, the ability to diagnose these defects is limited today. Reduced recombination is correlated with all trisomic conditions, including Down's syndrome (trisomy 21), Edward's syndrome (trisomy 18), Patu's syndrome (trisomy 13)112, nonobstructive azoospermia113 and male infertility due to sperm aneuploidy114,115. Diagnosis of female endocrine disorders affecting ovulation and structural defects of the female genital tract are routine; however, assessment of the genetic basis for some of the common female infertility syndromes presents diagnostic challenges. Clinicians should not perform transrectal ultrasonography (TRUS) or pelvic MRI as part of the initial evaluation of the infertile male. Clinicians should not routinely perform scrotal ultrasound in the initial evaluation of the infertile male. Differentiation of obstructive azoospermia from NOA may most frequently be predicted from clinical and laboratory results without the need for surgical diagnostic biopsy. When present, various treatments have been employed including the use of TESE with ICSI, antioxidant administration, donor sperm, varicocele repair, and/or frequent ejaculation. Men who were obese had a higher percentage of sperm with DNA fragmentation, abnormal morphology, and low mitochondrial membrane potential (MMP), and were more likely to be infertile . This may result in transient azoospermia with a recovery period of possibly even up to 2 years. A retrospective study found that ASIH was the most common cause of profound hypogonadism (≤50 ng/dL testosterone) amongst men who sought treatment for hypogonadism . In another study, Zhang et al. noted a significant rise in sperm concentration and sperm motility after transferring fecal microbiota from alginate oligosaccharide-treated mice to busulfan-treated mice. Ding et al. found a marked reduction in sperm concentration and motility in mice subjected to a high-fat diet. Figure 1 presents an overview of the locations and components of the male microbiome, along with potential interventions. Clinicians should use the results from the semen analysis to guide management of the patient. Lead has been documented to be a reproductive toxicant for many years.90 Routes of exposure include ingestion, inhalation, or skin contact. Additionally, it was difficult to ascertain the impact of losing a testicle (as opposed to just having testicular cancer), as well as some of the hormonal abnormalities seen, such as elevated human chorionic gonadotropin (hCG). An imbalance in the hypothalamic-pituitary-gonadal axis can result in infertility and hypogonadism. It can be useful in diagnosing cases of infertility or success of a vasectomy. It is released within a fluid that mixes with the sperm to form semen. The first stage of spermatogenesis begins with mitosis of diploid spermatogonia into primary spermatocytes. During the stressful pre-examination period, stress scores and SOD activity was increased, whilst sperm concentration and motility were decreased compared to the post-examination non-stress period. In another study amongst healthy volunteers, the effect of examination stress was investigated on seminal antioxidant content and sperm quality. Another study evaluated the associations between work-related stress, stressful life events, and perceived stress on semen quality. Similarly, in an animal model study, acute restraint stress was shown to suppress sperm motility from 30 min of restraint onwards. Weight loss and lowering of BMI have helped improve sperm quality in some, but not all men . Herein we will provide a basic overview of treatment for infertility. Treatment for male factor infertility varies based on the underlying cause. Scrotal ultrasound is not recommended in the routine evaluation of a patient with infertility.(Brannigan RE, 2024) It may be considered for patients with an abnormality identified on physical examination such as a testicular or extra-testicular scrotal mass. A large meta-analysis involving males from 26 countries/regions concluded that smoking causes a decline in sperm quality in both fertile and infertile men . The remaining 74 reports were reviewed for data on the association between a particular lifestyle factor and male infertility. Of these, 30 reports were excluded as the full-text could not be retrieved and the abstract did not have data on the association between the lifestyle factor of interest and male infertility. The remaining 74 reports were reviewed for data on association between a particular lifestyle factor and male infertility and were included in the present review. Frequently, their diagnoses are either descriptive (without a mechanistic basis) or unknown (idiopathic), and their treatment involves ART. An overriding goal of translational research is to define specific defective pathways in disease and to use this information to improve clinical diagnosis and treatment. Mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene mainly results in two autosomal recessive genetic disorders, cystic fibrosis and CBAVD. The communities play pivotal roles in reproductive health, and their imbalances can lead to conditions like infertility. By integrating genetic, environmental, and microbial factors, precision medicine aims to provide more targeted diagnostics, preventions, screening, and treatments 31,32. These varied findings underscore the multifaceted nature of male fertility and the potential influence of factors such as obesity, diet patterns, and environmental toxins . Notably, the application of precision medicine, which customizes treatments based on individual microbial profiles and specific causes of infertility, emerges as a promising approach to enhance treatment outcomes. In addition, the processes of mitosis and meiosis vary between the ovary and testis, but they are highly regulated by both endocrine and paracrine factors (reviewed in ref. 1). Other male genes downstream of SRY include GATA-binding protein-4 (GATA4), Zinc finger protein, multitype-2 (ZFPM2, also know as FOG2), Wilm's tumor-1 (WT1) and NR0B1 (DAX1), whereas the gonadal target genes of SOX9 include AMH, FGF9, desert hedgehog (DHH), prostaglandin D synthase (PTGDS), and VANIN1 (VNN1)45. In the absence of SRY, levels of RSPO1 rise and cause increased WNT4 activity and β-catenin (β-Cat) signaling by inhibiting internalization of the WNT co-receptor, low-density lipoprotein receptor–related protein-6 (LRP6; ref. 222), resulting in an ovary. Likewise, many autosomal gene products function in the formation of the bipotential gonad, including Wilms tumor 1 (WT1) and steroidogenic factor 1 (SF1, officially known as NR5A1). In humans, reduction of CatSper protein and expression levels is reported in immotile or less motile sperm89,96. Other clues to the regulation of sperm motility come from the studies of the plasma membrane ion channels that regulate intracellular calcium channels and potassium currents in sperm. In the flagellum, the fibrous sheath surrounds the axoneme and outer dense fibers, functioning not only structurally during flagellar beating but also as a scaffold for the glycolytic machinery necessary to generate the energy necessary for sperm motility79. The routine semen analysis evaluates the ejaculate for abnormalities of sperm number, morphology and motility. Like endometriosis, PCOS has been the subject of family studies attempting to identify genetic susceptibility loci75; one was mapped to chromosome 19p13.2 and linked to the dinucleotide repeat marker, D19S884. The head of the sperm contains the extremely compact haploid nucleus with very little cytoplasm. Approximately 100 to 300 million sperm are produced each day, whereas women typically ovulate only one oocyte per month. Eventually, the sperm are released into the lumen and are moved along a series of ducts in the testis toward a structure called the epididymis for the next step of sperm maturation. Individuals and couples have the right to decide the number, timing and spacing of their children. In addition, exposure to environmental pollutants and toxins can be directly toxic to gametes (eggs and sperm), resulting in their decreased numbers and poor quality (1,2). Join our community dedicated to excellence and innovation in fertility care. There were 22 studies of interest that were included in the evidence base. In 2023, the Male Infertility Guideline was updated through the AUA amendment process in which newly published literature is reviewed and integrated into previously published guidelines. A male evaluation is necessary to adequately design the management of the patient and the couple. Some conditions are life threatening, while others have health and genetic implications for the patient and potential offspring. In contrast, current clinical evaluation of infertile couples is relatively simple and superficial. These stem cells may also offer a renewable source of cells to be used to correct a variety of diseases of aging, to develop new cell-based therapies for a wide range of diseases and to advance germline gene therapy to ameliorate genetic diseases in offspring. Culture and manipulation of rodent spermatogonial stem cells shows promise203,204, with reports of gene manipulation in spermatogonial stem cells in vitro199,205. In a prospective cohort study of over 100 couples with high DNA fragmentation, testicular sperm yielded substantially higher live birth rates than ejaculated sperm.143 The routine clinical application of this practice remains controversial as the quality of the study data is low. Therefore, DNA fragmentation testing may be advantageous for males in couples undergoing IVF with repeated IVF failure. The goal of genetic testing for a CFTR mutation is to help identify the etiology of infertility as well as provide counseling on potential offspring transmission. It should be noted that American College of Obstetricians and Gynecologists (ACOG) pre-conception counseling guidelines include offering genetic screening, including CF mutations, for all couples considering pregnancy.137 Optic microscopy is used to visualize and determine the concentration of the sperm. In terms of genetic disorders, the main structural abnormalities are Robertsonian and reciprocal translocations. Additionally, anti-Muller hormone (AMH), vitamin D, complete blood count, and iron levels are determined, irrespective of menstrual cycle phase. Hormone level assessment is also required and involves FSH, LH, estrogen, progesterone, prolactin, and TSH levels. For males who harbor a CFTR mutation or have absence of the vas deferens (unilateral or bilateral), clinicians should recommend genetic evaluation of the female partner. In addition to classic mutations, the 5T variant of the polythymidine tract in the splice site of intron 8 (which regulates exon 9 splicing efficiency) is also commonly found in males with obstructive azoospermia due to CFTR abnormalities. Clinicians should recommend Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) mutation carrier testing (including assessment of the 5-thymidine 5T allele) in males with vasal agenesis or idiopathic obstructive azoospermia. Y-chromosome microdeletions are the second most common known genetic cause of infertility in the male. Viable sperm from urine or any location within the male reproductive tract can be used with IUI and ART to achieve a pregnancy.106 They can detect and characterize both culturable and non-culturable bacteria, shedding light on functional pathways and interactions within the microbiota 76,102,103,104,105. However, their specificity can sometimes limit the full coverage of microbial diversity and they might not provide insights into the functional capabilities of the microbiota 76,102. To solidify the findings from these studies, more extensive, longitudinal research across multiple institutions is essential. Additionally, a statistically significant negative correlation was observed between the abundance of Prevotella and semen concentration. Vitalrize, formerly known as Prolong Power, is a revolutionary male enhancement supplement designed to boost stamina, energy, and confidence. When it comes to erectile dysfunction, CBD may help by improving blood flow to the penis, reducing anxiety and stress, and enhancing overall sexual performance. CBD works by interacting with the body’s endocannabinoid system, which plays a key role in regulating various physiological processes, including sexual function. With their potential to improve blood flow, reduce anxiety, and enhance sexual performance, these gummies offer a safe and effective alternative to traditional ED treatments. Testicular steroidogenesis (the manufacture of androgens, including testosterone) results in testosterone concentrations that are 100 times higher in the testes than in the circulation. The alternate term for Leydig cells, interstitial cells, reflects their location between the seminiferous tubules in the testes. Erectile dysfunction (ED) is a condition in which a man has difficulty either initiating or maintaining an erection. Harnessing the insights from precision medicine and understanding the impact of microbial factors on fertility can usher in a new era in reproductive medicine, offering hope and solutions for couples facing infertility challenges. By exploring the role of the microbiome in male infertility, this review seeks to pave the way for innovative treatment approaches. Increased BMI is negatively correlated to male fertility (118); however, there is inconclusive evidence from interventional studies to suggest that weight loss is an effective therapy for male infertility. A critical point to note is that sperm production takes between 65 to 90 days. Each organ has a specific role in producing and delivering healthy sperm. Men with sperm parameters below the World Health Organization (WHO) normal values are considered to have male factor infertility (36) and semen quality is used as a surrogate measure of male fecundity (35). Conventional semen analysis is the hallmark diagnostic test for male infertility (Table 1). Furthermore, male infertility is increasingly observed as a “canary in the coal mine” for future male health conditions (8), with an association with cardiovascular disease, testicular cancer, quality of life, and increased all-cause mortality (9). The review is an evidence-based summary of male infertility due to testicular failure with a focus on etiology, clinical assessment, and current management approaches. Historically, the absence of microbial growth in male reproductive tract samples was interpreted as an absence of microbial infection. Some studies have documented a decline in semen parameters 3,4,5, while others have reported stable 6,7,8 or even improved semen quality over time 9,10,11. Couples grappling with infertility often face emotional, social, and financial challenges, further underscoring the need for effective interventions . Infertility, as defined by the World Health Organization, is the inability of couples to conceive after engaging in regular sexual intercourse for over one year without the use of contraception . Developmentally, however, male and female fetuses are essentially indistinguishable until midgestation in the mouse and approximately six weeks of pregnancy in humans. Although the development of ART has allowed otherwise hopelessly infertile couples to experience the joy of parenthood, these technologies also traverse the natural barriers preventing the transmission of genetic defects. Certainly, progress in the field of reproduction has been realized in the twenty-first century with advances in the understanding of the regulation of fertility, with the production of over 400 mutant mouse models with a reproductive phenotype and with the promise of regenerative gonadal stem cells. For other individuals with a known etiology, effective cures are lacking, although their infertility is often bypassed with assisted reproductive technologies (ART), some accompanied by safety or ethical concerns. While RR of infertility for an individual patient can be estimated, it is usually not possible to predict whether a patient is fertile or infertile based solely on SA parameters.28 The OR for infertility increases as the number of abnormal parameters increases.28 Clinicians managing results from an SA should counsel patients that multiple significant abnormalities in semen parameters increase their RR for infertility. Sites of lead toxicity are the central nervous system and the gonad, causing direct interference with the ability of spermatozoa to undergo the acrosome reaction, thus leading to infertility. Studies evaluating the impact of environmental factors on male fertility are difficult to conduct and analyze because many chemicals are ubiquitous, methods of measurement of exposure are inadequate, few biomarkers of toxicity are validated, and confounding factors complicate the interpretation of the data. The higher the dose and the greater the number of cycles (especially above 2 cycles), the greater the likelihood of failure to recover normal sperm concentrations (defined These data strongly suggest not performing a SA within the first 12 months after treatment completion and, where possible, to assess sperm recovery at a time point 2 to 3 years after treatment ends. The azoospermia and sperm concentration data were also consistent across various types of cancers and when comparing chemotherapy versus radiation for testis cancer. The nature of this return depends on numerous factors including the cancer type, type of treatment administered, treatment dosing, and the duration after completion of treatment at which the SA is performed. Since approximately 50% of sperm do not survive semen processing, a total motile count of at least 5 to 10 million sperm is usually required to allow for an adequate number of motile sperm for insemination. This will allow the patient sufficient time to submit one or more semen samples, or potentially undergo a sperm extraction (electroejaculation or TESE) in the event of an unsuccessful attempt at sperm banking (inability to ejaculate or a semen sample with no viable sperm).307, 308 The fifth stage of germ cell formation—spermatozoa, or formed sperm—is the end result of this process, which occurs in the portion of the tubule nearest the lumen. A process called spermiogenesis transforms these early spermatids, reducing the cytoplasm, and beginning the formation of the parts of a true sperm. This second meiotic division results in a total of four cells with only half of the number of chromosomes. While the reduction in sex steroids in men is akin to female menopause, there is no clear sign—such as a lack of a menstrual period—to denote the initiation of andropause. The resulting reduction in circulating testosterone concentrations can lead to symptoms of andropause, also known as male menopause. In the testis, LH binds to LH receptors on Leydig cells and stimulates the release of testosterone. Testicular biopsy is almost always performed in association with surgical sperm retrieval (see section on ‘Surgical sperm retrieval techniques’). The upper reference limit for serum FSH may often be higher in commercial assay kits due to inclusion of unselected older men or those with unrecognized reproductive illness (167). A typical feature of OA is an entirely normal endocrine profile (and testicular volume). Impairment of testosterone secretion forms the main basis underlying the detrimental effects of psychological stress on spermatogenesis . This leads to changes in Sertoli cells and the blood–testis barrier, which ultimately causes spermatogenesis to be suppressed. Some studies have pointed towards a more permanent repercussion of steroid use on male fertility and as such, AAS use should be highly discouraged . Both acute and chronic exposure to cocaine disrupted spermatogenesis and damaged the testicular ultrastructure , . If abnormalities are seen on an initial semen analysis, it is often recommended to repeat the test approximately one month later to confirm the original findings. The utility of these home kits compared to a standard semen analysis remains under investigation. Several companies are now offering qualitative and quantitative semen analysis testing using home kits. Proper semen analysis takes time and very specialized training by an andrologist, so ideally this test is performed at a lab with experience. (Table 3) (World Health Organization, 2021) There are several important things to know about a semen analysis to be able to properly interpret the results. Deregulation of the endogenous cannabinoid system (ECS) was shown to significantly impair spermatogenesis resulting in lower total sperm count and motility . Marijuana, cocaine, anabolic–androgenic steroids (AAS), opiates (narcotics), and methamphetamines are examples of illicit drugs that exert a negative impact on male fertility. Similarly, another study found alcohol consumption rates to be significantly higher in men with severe oligozoospermia and with non-obstructive azoospermia compared to fertile controls . None of the heavy alcohol drinkers were normozoospermic and most were oligozoospermic (64%), which is suggestive of progressive testicular damage in relation to increasing daily alcohol intake . The Male Infertility Panel was created in 2017 by the American Urological Association Education and Research, Inc. (AUAER) and ASRM. The risk of pregnancy loss after two losses is at least 25% depending on the age of the woman. For the woman, ovarian reserve is helpful in predicting her response to medications, but this is not an absolute predictor of fertility. In patients with endometriosis, the peritoneal cavity can be filled with macrophages which leads to an increase in the production of pro-inflammatory factors, thus stimulating inflammation (6). A relatively common pelvic disease in infertile women is endometriosis, which implies ectopic endometrial tissue in the peritoneal cavity. Functional abnormalities of the fallopian tube can be caused by pelvic inflammatory disease, ruptured appendicitis, or ectopic pregnancy.