Endocrine evaluation of infertile men

Overview of infertility

Having a child is an innate trait in animals, including humans, and is required for the continued existence of all animal species. Therefore, for most women, the inability to conceive or to do so in a timely fashion - termed infertility - to enable the continuation of the family line can be emotionally distressing. The definition of infertility is controversial because of its separation into primary and secondary. This is further complicated by the loosely used term subfertility, which relates to couples who have reduced ability because they take longer than the natural time to conceive, as opposed to those who are infertile and are entirely unable to conceive after 6 to 12 months, depending on age. Infertility evaluation requires a thorough male and female history, physical examination of both partners, and targeted investigation to determine the cause of infertility in a particular couple. Various treatments apply to infertile couples depending on the age of the female partner, the results of investigations, the reason for infertility, the presence of inheritance of abnormal genes, the pregnancy rates the couple is happy with, the resources available, how desperate the couple is to achieve a live birth, and how much they want to commit to treatment. Infertility treatment could include counseling and expectant management only, intrauterine insemination in a natural or stimulated cycle, and IVF and or ICSI. Men with azoospermia will need surgical options to retrieve sperm for IVF/ ICSI, but rarely for IUI. This review overviews infertility's etiology, diagnosis, investigations, and treatment.

Differentiation between nonobstructive azoospermia and obstructive azoospermia: then and now

ABSTRACT

Male infertility has seen an increase in prevalence with cases of azoospermia estimated to affect 10%-15% of infertile men. Confirmation of azoospermia subsequently necessitates an early causal differentiation between obstructive azoospermia (OA) and nonobstructive azoospermia (NOA). Although less common when compared to NOA, OA can represent upward 20%-40% of cases of azoospermia. While there are a multitude of etiologies responsible for causing NOA and OA, correctly distinguishing between the two types of azoospermia has profound implications in managing the infertile male. This review represents an amalgamation of the current guidelines and literature which will supply the reproductive physician with a diagnostic armamentarium to properly distinguish between NOA and OA, therefore providing the best possible care to the infertile couple.

Nonobstructive azoospermia: an etiologic review

ABSTRACT

Azoospermia is the complete absence of spermatozoa in the ejaculate in two or more semen analyses after centrifugation. Nonobstructive azoospermia (NOA) represents the most severe form of male factor infertility accounting for 10%-15% of cases and stems from an impairment to spermatogenesis. Understanding of the hypothalamic-pituitary-testicular axis has allowed NOA to be subcategorized by anatomic and/or pathophysiologic level. The etiologies of NOA, and therefore, the differential diagnoses when considering NOA as a cause of male factor infertility, can be subcategorized and condensed into several distinct classifications. Etiologies of NOA include primary hypogonadism, secondary hypogonadism, defects in androgen synthesis and/or response, defective spermatogenesis and sperm maturation, or a mixed picture thereof. This review includes up-to-date clinical, diagnostic, cellular, and histologic features pertaining to the multitude of NOA etiologies. This in turn will provide a framework by which physicians practicing infertility can augment their clinical decision-making, patient counseling, thereby improving upon the management of men with NOA.

Environmental and occupational exposure to cadmium associated with male reproductive health risk: a systematic review and meta-analysis based on epidemiological evidence

There is an abundance of epidemiological evidence and animal experiments concerning the correlation between cadmium exposure and adverse male reproductive health outcomes. However, the evidence remains inconclusive. We conducted a literature search from PubMed, Embase, and Web of Science over the past 3 decades. Pooled r and 95% confidence intervals (CIs) were derived from Cd levels of the type of biological materials and different outcome indicators to address the large heterogeneity of existing literature. Cd was negatively correlated with semen parameters (r = - 0.122, 95% CI - 0.151 to - 0.092) and positively correlated with sera sex hormones (r = 0.104, 95% CI 0.060 to 0.147). Among them, Cd in three different biological materials (blood, semen, and urine) was negatively correlated with semen parameters, while among sex hormones, only blood and urine were statistically positively correlated. In subgroup analysis, blood Cd was negatively correlated with semen density, sperm motility, sperm morphology, and sperm count. Semen Cd was negatively correlated with semen concentration. As for serum sex hormones, blood Cd had no statistical significance with three hormones, while semen Cd was negatively correlated with testosterone. In summary, cadmium exposure might be associated with the risk of a decline in sperm quality and abnormal levels of sex hormones.

Assessing the Prevalence of Low Testosterone and Elevated Follicle Stimulating Hormone Among Men Presenting for Fertility Evaluation Without Oligospermia

OBJECTIVE

To compare the prevalence of abnormal hormone parameters among men with and without oligospermia to determine the value of universal hormonal screening during initial fertility evaluation.

MATERIALS AND METHODS

We retrospectively evaluated men who underwent semen analysis and hormonal evaluation (morning testosterone [T] and follicle-stimulating hormone [FSH]) between January 2002 and May 2021. Sperm concentration was dichotomized at 15 million/mL according to World Health Organization (WHO) criteria. We compared median and interquartile range (IQR) T and FSH levels according to sperm concentration using Kruskal-Wallis test. Differences in prevalence of low testosterone (<300 ng/dL) and abnormal FSH (>7.6mIU/mL) were determined using chi-square test.

RESULTS

1164 men had a morning serum T. There was no difference in median T among men with normal vs abnormal sperm concentration (316 ng/dL, IQR 250-399 vs 316 ng/dL, IQR 253-419; P = .52). FSH was measured in 1261 men. Median FSH was higher among men with sperm concentration <15 million/mL (6.0IU/mL, IQR 3.9-10.7 vs 3.8IU/mL, IQR 2.7-5.7; P < .001). Among men with ≥15 million/mL concentration, 44.1% were found to have low T (P = .874) and 10.8% had an FSH ≥7.6 mIU/mL (P < .001). Among men with ≥15 million/mL sperm concentration who underwent both T and FSH evaluation, 43.6% had at least 1 hormonal abnormality.

CONCLUSION

Almost half of men with normal sperm concentration had low T. As low T may have long-term implications for both fertility and overall health, providers should consider universal T screening in men presenting for fertility evaluation.

Inflammasomes in human reproductive diseases

Inflammasomes are multi-protein complexes localized within immune and non-immune cells that induce caspase activation, proinflammatory cytokine secretion, and ultimately pyroptosis-a type of cell death. Inflammasomes are involved in a variety of human diseases, especially acute or chronic inflammatory diseases. In this review, we focused on the strong correlation between the NLRP3 inflammasome and various reproductive diseases, including ovarian aging or premature ovarian insufficiency, PCOS, endometriosis, recurrent spontaneous abortion, preterm labor, pre-eclampsia, and male subfertility, as well as the multifaceted role of NLRP3 in the pathogenesis and treatment of these diseases. In addition, we provide an overview of the structure and amplification of inflammasomes. This comprehensive review demonstrates the vital role of NLRP3 inflammasome activation in human reproductive diseases together with the underlying mechanisms, offers new insights for mechanistic studies of reproduction, and provides promising possibilities for the development of drugs targeting the NLRP3 inflammasome for the treatment of reproductive disorders in the future.

Male factor infertility: A contemporary overview of investigation, diagnosis and management

Infertility, defined as the failure to achieve a clinical pregnancy after 1 year of regular, unprotected sexual intercourse, is a public health issue of global concern. It affects up to 12% of couples worldwide. While traditionally, research and treatment have focused on female causes of infertility, male factors contribute to up to 70% of cases and therefore deserve appropriate recognition. The purpose of this comprehensive review is to detail the diagnostic work-up, investigations and management of male factor infertility. We discuss much-debated pathologies, such as varicocele, and novel investigations, including sperm DNA fragmentation and reactive oxygen species.

Level of evidence: Not applicable

Assessment of hormonal status in male infertility. An update

BACKGROUND AND AIMS

The prevalence and incidence of infertility are increasing worldwide; they are associated with a significant economic and social impact. Infertility is defined as the inability to achieve pregnancy after 12 months or more of regular unprotected sex. In recent times, the male factor has gained importance and currently it contributes to approximately 50% of infertility cases. Multiple etiologies are stated, such as metabolic, anatomical, genetic or even idiopathic causes; however, the main cause is semen abnormalities. The aim of this manuscript is to provide a complete review of hormonal assessment of male infertility, as well as to review the physiology and pathophysiology related to the male gonadal axis.

METHODS

This study is a narrative abstract carried out on basis of systematic bibliographic review, using articles indexed in PubMed/Medline, Scopus, Embase and Scielo, which were published during the last 20 years.

RESULTS

The cornerstone of the evaluation of the hormonal status is semen analysis. Clinicians must rule out hypogonadism in those patients who present oligospermia and azoospermia, by determining levels of testosterone and gonadotropins, which provide the functionality status of the hypothalamic-pituitary-testicular axis. Evaluation of the adrenal, thyroid, and lactotroph axis are indicated in those patients with central hypogonadism.

CONCLUSIONS

Despite advances in the diagnosis of male infertility, some causes are not fully understood, therefore, it is crucial to perform a timely hormonal evaluation of the male factor in infertile couples, in order to provide adequate treatment and improve fertility rates.

Cellular Therapy via Spermatogonial Stem Cells for Treating Impaired Spermatogenesis, Non-Obstructive Azoospermia

Male infertility is a major health problem affecting about 8–12% of couples worldwide. Spermatogenesis starts in the early fetus and completes after puberty, passing through different stages. Male infertility can result from primary or congenital, acquired, or idiopathic causes. The absence of sperm in semen, or azoospermia, results from non-obstructive causes (pretesticular and testicular), and post-testicular obstructive causes. Several medications such as antihypertensive drugs, antidepressants, chemotherapy, and radiotherapy could lead to impaired spermatogenesis and lead to a non-obstructive azoospermia. Spermatogonial stem cells (SSCs) are the basis for spermatogenesis and fertility in men. SSCs are characterized by their capacity to maintain the self-renewal process and differentiation into spermatozoa throughout the male reproductive life and transmit genetic information to the next generation. SSCs originate from gonocytes in the postnatal testis, which originate from long-lived primordial germ cells during embryonic development. The treatment of infertility in males has a poor prognosis. However, SSCs are viewed as a promising alternative for the regeneration of the impaired or damaged spermatogenesis. SSC transplantation is a promising technique for male infertility treatment and restoration of spermatogenesis in the case of degenerative diseases such as cancer, radiotherapy, and chemotherapy. The process involves isolation of SSCs and cryopreservation from a testicular biopsy before starting cancer treatment, followed by intra-testicular stem cell transplantation. In general, treatment for male infertility, even with SSC transplantation, still has several obstacles. The efficiency of cryopreservation, exclusion of malignant cells contamination in cancer patients, and socio-cultural attitudes remain major challenges to the wider application of SSCs as alternatives. Furthermore, there are limitations in experience and knowledge regarding cryopreservation of SSCs. However, the level of infrastructure or availability of regulatory approval to process and preserve testicular tissue makes them tangible and accurate therapy options for male infertility caused by non-obstructive azoospermia, though in their infancy, at least to date.

Induction of spermatogenesis in men with hypogonadotropic hypogonadism

PURPOSE

We compared our clinical experience to international standards, assessed by response to treatment and pregnancy rates to ensure our results were comparable.

METHODS

Men presenting with azoospermia related to hypogonadism were recruited into a treatment programme which was managed by one person over 8 years in a secondary care facility. Treatment followed published management plans using urinary gonadotropins. Data were collected on success rates in spermatogenesis, as well as variables which might predict success, and costs. Statistical analysis used non-parametric methods.

RESULTS

Of 16 men with HH, 14 achieved spermatogenesis, and 9 had sperm cryopreserved. Of those 14, 6 were successful in achieving a pregnancy with their partner from assisted conception (including ICSI) and one after natural conception. Factors identified to identify men likely to be successful in treatment were whether testicular volume was larger at onset of gonadotropins (median 10 mL) with a trend towards greater success if the cause developed after puberty. Mean treatment costs per man treated amounted to GP£4379/UD$5377 (figures for September 2020). Success rates from this treatment should exceed 70% in most clinical settings. The likelihood of success improves when testicular volume exceeded 10 mL at initiation of treatment and a trend exists whereby success is more likely whereby when hypogonadism developed after puberty. Treatment costs are at a level likely to benefit quality of life, supporting the delivery of this treatment and where necessary and possible, funding it in line with other fertility treatments. This treatment should be available much more widely as a management option for men with hypogonadism, allowing them to father a biological child, rather than using donor sperm.

Prevalence of Hyperprolactinemia and Clinically Apparent Prolactinomas in Men Undergoing Fertility Evaluation

OBJECTIVE

To determine prevalence of hyperprolactinemia and prolactinoma among men presenting for initial fertility evaluation.

METHODS

We performed a retrospective review of men presenting for initial fertility evaluation at a tertiary care, academic health system between 1999 and 2018. Men with measured prolactin levels were analyzed to determine prevalence of hyperprolactinemia and prolactinoma. We compared clinical characteristics of men with and without hyperprolactinemia. Univariable and multivariable analysis were used to determine factors associated with hyperprolactinemia. We assessed effects of hyperprolactinemia and prolactinoma on testosterone levels, semen parameters and pregnancy outcomes after treatment.

RESULTS

3,101 men had serum prolactin level measured. 65 (2.1%) had hyperprolactinemia. Patients with hyperprolactinemia had lower testosterone (median 280 ng/dL vs. 313 ng/dL, p=0.038) and lower total motile sperm count (TMSC) (median 7.0 million vs. 34.7 million, p=0.001) compared to men without hyperprolactinemia. 43.1% of men with hyperprolactinemia had oligospermia versus 21.5% of men without hyperprolactinemia (p<0.001). Univariable analysis demonstrated that men with elevated luteinizing hormone (LH) (OR 1.077, p=0.001) and follicle-stimulating hormone (FSH) (OR 1.032, p=0.002) were more likely to have hyperprolactinemia. Men with oligospermia were more likely to have hyperprolactinemia (OR 2.334, p=0.004). On multivariable analysis, neither hormone parameters nor oligospermia were associated with elevated prolactin (p>0.05). Of the 65 men with hyperprolactinemia, 11 (17%) were diagnosed with a prolactinoma, resulting in an overall prevalence of 11 in 3,101 (0.35%).

CONCLUSION

The overall prevalence of prolactinoma in our cohort of men undergoing fertility evaluation was 35-fold higher than the prevalence in the general male population.

Low Testosterone and Semen Parameters in Male Partners of Infertile Couples Undergoing IVF with a Total Sperm Count Greater than 5 Million

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.

Clomiphene citrate improved testosterone and sperm concentration in hypogonadal males

When considering empirical medical management (EMT) options for men with unexplained infertility (UI), clomiphene citrate (CC) has been shown to positively influence sperm parameters in hypogonadal men. Unfortunately, the optimal cut point for defining hypogonadism for this patient population has not been established. We hypothesized that hypogonadal men with UI having the lowest serum total testosterone (TT) (<265 ng/dL) would have a significant post-CC improvement in both TT and semen characteristics compared to those in the TT > 264 ng/dL group. We performed our study based on an IRB-approved retrospective chart review of 83 males with UI receiving more than 90 days of 50 mg daily CC. Serum TT and semen characteristics were studied in 83 patients before and in 23 patients after CC treatment. Median TT level increased from 256 ng/dL to 630 ng/dL (p < 0.001, n = 83) and SC increased from 6 ( 10 6 /ml) to 20 ( 10 6 /ml) (p < 0.016, n = 23). Overall, our results demonstrated the following: (1) CC treatment at all currently used serum TT cut-points resulted in significant improvement in both TT (p < 0.001) and sperm concentration (p = 0.03). No significant change in post-CC sperm motility or morphology was noted. (2) Correlation and linear regression analyses demonstrated that CC treatment significantly increased TT in 96% (22 of 23) of patients, and (3) when grouped as two cohorts (≤264 and >264 ng/dL), sperm concentration and TT improved 2.3 to 2.6-fold (p < 0.001) and 1.45 to 2.5-fold (p < 0.01) respectively. Thus, for hypogonadal men with UI, CC significantly improved TT and sperm concentration regardless of pre-treatment, baseline serum TT level. For this reason, CC treatment should be considered in men with UI having a TT < 400 ng/dL.

Cutting-Edge Evaluation of Male Infertility

A male factor is a contributor in 50% of cases of infertility. Although assisted reproductive techniques can often bypass the need to improve semen parameters, the evaluation of the infertile man remains critical. Current methods for evaluating the infertile man are discussed, beginning with the basic workup that all suspected infertile men should undergo, followed by subsequent evaluation steps. Although the fundamental components of the evaluation have remained consistent, several new tools are available to assist in identifying the underlying etiology. As our understanding of male fertility expands, the technologies available to diagnose and ultimately treat it continue to evolve.

Optimal Endocrine Evaluation and Treatment of Male Infertility

This article aims to define the optimal endocrine workup of male factor infertility, including evaluation and treatment of men who have previously been on exogenous testosterone or anabolic steroids. Future directions include the expansion of genetic testing for infertility to include endocrine gene products.

A review of hypogonadotropic hypogonadism cases followed up in our clinic in the last decade

INTRODUCTION

The aim of the present study was to evaluate, with this retrospective study, the patients with hypogonadotropic hypogonadism, who were followed up in our clinic in the last decade and were reviewed in terms of the incidence of the disease, diagnostic methods and differential diagnoses, treatment modalities, fertility rates, and treatment success.

METHODS

After a very careful differential diagnosis, 81 patients (1.5% of infertile men presenting to the outpatient clinic) were diagnosed with hypogonadotropic hypogonadism. This study only included patients diagnosed with idiopathic hypogonadotropic hypogonadism. The treatment was undertaken in two periods depending on whether or not the patients wanted to have children at that time: testosterone replacement therapy and gonadotropin therapy. To induce spermatogenesis, the patients were treated using human chorionic gonadotropin and urinary or recombinant follicle-stimulating hormone.

RESULTS

The pregnancy rates of the spouses of the patients were as follows: spontaneous 64.6% (n = 42), intrauterine insemination 12.3% (n = 8), in vitro fertilization 15.3% (n = 10), and microscopic testicular sperm extraction + intracytoplasmic sperm injection 4.6% (n = 3).

CONCLUSION

Idiopathic hypogonadotropic hypogonadism is a rare but easily diagnosable and treatable cause of male infertility. After a long period of the treatment, almost all idiopathic hypogonadotropic hypogonadism patients can be treated with gonadotropins (human chorionic gonadotropin + follicle-stimulating hormone) in order to have children. The most important issue in the treatment is the dose of the drugs used in the treatment and the duration of the treatment. The most important result is that the required gonadotropin dose varies according to each patient. Therefore, the treatment dose and duration should be increased until patients have children.

Association between testosterone, semen parameters, and live birth in men with unexplained infertility in an intrauterine insemination population

OBJECTIVE

To determine whether men with unexplained infertility and low total T (TT) have abnormal spermatogenesis and lower fecundity.

DESIGN

Secondary analysis of the prospective, randomized, multicenter clinical trial, Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS).

SETTING

Infertility clinics.

PATIENT(S)

Nine hundred couples with unexplained infertility enrolled in AMIGOS. Semen analysis with an ejaculate of at least 5 million total motile sperm was required for enrollment. For inclusion in this secondary analysis, a fasting TT was required.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Logistic regression, adjusted for age and body mass index, assessed the association between low TT (defined as <264 ng/dL), semen parameters, and pregnancy outcome.

RESULT(S)

Seven hundred eighty-one men (mean age, 34.2 ± 5.7 years) with a median (interquartile range) TT of 411 (318-520) ng/dL were included. Men with TT <264 ng/dL were less likely to have normal (≥4% strict Kruger) morphology (unadjusted odds ratio [OR], 0.56; 95% confidence interval [CI], 0.34, 0.92; adjusted OR, 0.59; 95% CI, 0.35, 0.99). There was no association between low TT and semen volume < 1.5 mL, sperm concentration < 15 × 10⁶/mL, or motility < 40%. Among couples whose male partner had low TT, 21 (18.8%) had a live birth, compared with 184 (27.5%) live births in couples with a male partner having TT > 264 ng/dL. The odds of live birth decreased by 40% in couples whose male partner had low TT (unadjusted OR, 0.60; 95% CI, 0.36, 1.00; adjusted OR, 0.65; 95% CI, 0.38, 1.12).

CONCLUSION(S)

In couples with unexplained infertility, low TT in the male partner was associated with abnormal sperm morphology and lower live birth rates.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01044862.

Inconsistent Adoption of World Health Organization V (2010) Semen Analysis Reference Ranges in the United States Eight Years After Publication

OBJECTIVE

To determine the percentage of laboratories in the United States that have adopted the World Health Organization 2010 (WHO 5) semen analysis (SA) reference values 6years after their publication.

METHODS

Laboratories were identified via 3 approaches: using the Clinical Laboratory Improvement Amendments (CLIA) website, the CDC's 2015 Assisted Reproductive Technology Fertility Clinical Success Rate Report, and automated web searches. Laboratories were contacted by phone or email to obtain de-identified SA reports and reference ranges.

RESULTS

We contacted 617 laboratories in 46 states, of which 208 (26.7%) laboratories in 45 states were included in our analysis. 132 (63.5%) laboratories used WHO 5 criteria, 57 (27.4%) used WHO 4 criteria, and 19 (9.1%) used other criteria. WHO 5 criteria adoption rates varied by geographic region, ranging from 87.5% (35/40) in the Midwest to 50.0% (33/66) in the West. There was a greater adoption rate of WHO 5 reference values in academic affiliated (23/26, 88.5%) compared to non-academic affiliated laboratories (110/182, 60.4%) (P = .028).

CONCLUSION

While the majority of laboratories have adopted WHO 5 criteria following its release 6years ago, a large percentage (36.5%) use what is now considered outdated criteria. This variability could result in the characterization of a male's semen values as being "within reference range" at one center and "outside of reference range" at another. This inconsistency in classification may result in confusion for the both patient and physician and potentially shift the burden of infertility evaluation and treatment to the female partner.

An Evaluation of Reported Follicle-stimulating Hormone, Luteinizing Hormone, Estradiol, and Prolactin Reference Ranges in the United States

OBJECTIVE

To characterize US clinical laboratory reference range reporting and testing methods of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and prolactin.

METHODS

One hundred and seventeen US laboratories were surveyed. Outcomes measured were variation in lower and upper limits of normal male reference ranges for serum FSH, LH, estradiol, and prolactin, method of analysis and source of reference range RESULTS: The upper limit of normal reference ranges for FSH, LH, estradiol, and prolactin varied substantially across laboratories compared to the lower limits. The range of upper limits of FSH, LH, estradiol, and prolactin respectively are 7.9-20.0, 4.9-86.5, 37.7-77.0, and 7.4-25.0. Ninety-four percent of laboratories performed measurements on in-house high throughput analyzer utilizing immunoassays. Seventy percent of reported reference ranges for each hormone were based on validation studies of the analyzer's package insert values. Ten percent of laboratories derived their own reference ranges. Both the validation studies and derivations were based on a limited number of patient samples, ranging from 20 to 200.

CONCLUSION

Current reference ranges are based on small population studies of men with unknown medical histories, sexual or reproductive function. Influence of race and age has not been evaluated and could potentially be important in normal variation. The absence of standard information has yielded a spectrum of upper and lower normal values, which could delay an appropriate male infertility evaluation. Our findings highlight the need for a large population study of males with known normal sexual and reproductive function to formulate more accurate clinical reference ranges.

Hormone-Based Treatments in Subfertile Males

Subfertility is defined as the condition of being less than normally fertile though still capable of effecting fertilization. When these subfertile couples seek assistance for conception, a thorough evaluation of male endocrine function is often overlooked. Spermatogenesis is a complex process where even subtle alterations in this process can lead to subfertility or infertility. Male endocrine abnormalities may suggest a specific diagnosis contributing to subfertility; however, in many patients, the underlying etiology is still unknown. Optimizing underlying endocrine abnormalities may improve spermatogenesis and fertility. This manuscript reviews reproductive endocrine abnormalities and hormone-based treatments.

The office visit

This article summarizes the current office-based evaluation of male infertility and offers speculation, based on current research, on the future evolution of this encounter. A comprehensive history, physical examination, and semen analysis remain paramount to directing the evaluation; however, new advances continue to refine diagnostic and treatment algorithms. Interpretation of the routine semen analysis as well as adjunctive assessments, including reactive oxygen species, DNA fragmentation, and fluorescent in situ hybridization (FISH) are discussed. The analysis of genetic and endocrine abnormalities is reviewed.

Azoospermia due to spermatogenic failure

This article summarizes the current literature regarding azoospermia caused by spermatogenic failure. The causes and genetic contributions to spermatogenic failure are reviewed. Medical therapies including use of hormonal manipulation, whether guided by a specific abnormality or empiric, to induce spermatogenesis are discussed. The role of surgical therapy, including a discussion of varicocelectomy in men with spermatogenic failure, as well as an in-depth review of surgical sperm retrieval with testicular sperm extraction and microdissection testicular sperm extraction, is provided. Finally, future directions of treatment for men with spermatogenic failure are discussed, namely, stem cell and gene therapy.

Unexplained male infertility: diagnosis and management

Unexplained male infertility is a diagnosis reserved for men in whom routine semen analyses results are within normal values and physical as well as endocrine abnormalities were ruled out. In addition to erectile problems and coital factors, immunologic causes and sperm dysfunction may contribute to such condition. New etiologies of unexplained male infertility include low level leukocytospermia and mitochondrial DNA polymerase gene polymorphism. Contemporary andrology may reveal cellular and sub-cellular sperm dysfunctions which may explain subfertility in such cases, thus aiding the clinician to direct the further work-up, diagnosis and counseling of the infertile male. The objective of this article is to highlight the concept of unexplained male infertility and focuses on the diagnosis and treatment of this condition in the era of modern andrology and assisted reproductive techniques. Extensive literature review was performed using the search engines: Pubmed, Science-direct, Ovid and Scopus.

The epidemiology and etiology of azoospermia

The misconception that infertility is typically associated with the female is commonly faced in the management of infertile men. It is uncommon for a patient to present for an infertility evaluation with an abnormal semen analysis report before an extensive female partner workup has been performed. Additionally, a man is usually considered fertile based only on seminal parameters without a physical exam. This behavior may lead to a delay in both the exact diagnosis and in possible specific infertility treatment. Moreover, male factor infertility can result from an underlying medical condition that is often treatable but could possibly be life-threatening. The responsibility of male factor in couple's infertility has been exponentially rising in recent years due to a comprehensive evaluation of reproductive male function and improved diagnostic tools. Despite this improvement in diagnosis, azoospermia is always the most challenging topic associated with infertility treatment. Several conditions that interfere with spermatogenesis and reduce sperm production and quality can lead to azoospermia. Azoospermia may also occur because of a reproductive tract obstruction. Optimal management of patients with azoospermia requires a full understanding of the disease etiology. This review will discuss in detail the epidemiology and etiology of azoospermia. A thorough literature survey was performed using the Medline, EMBASE, BIOSIS, and Cochrane databases. We restricted the survey to clinical publications that were relevant to male infertility and azoospermia. Many of the recommendations included are not based on controlled studies.

Associations between testosterone, bone mineral density, vitamin D and semen quality in fertile and infertile Chinese men

Testosterone (T) and vitamin D (VD) interact in androgen deficient men, however, this interaction and subsequent semen quality and bone mineral density (BMD) status is not clear in infertile men. Our objective was to investigate T, VD, semen quality, BMD and their relationships in Chinese infertile men. We conducted a cross-sectional study of 559 men aged 20-40 years, including 195 fertile men, 9 infertile men with known risk factors for osteoporosis (WR) and 355 infertile men without known risk factors for osteoporosis (WOR). WOR infertile men constituted 314 oligo-, astheno-, teratospermic or normospermic infertile men (OATN men) and 41 non-obstructive azoospermic men (NOA men). Differences of parameters were assessed, and the relationships were adjusted by multiple linear regression. WOR infertile men had significantly lower T, lumbar spine and total hip BMD than fertile men (all p < 0.05). Bioavailable T (Bio-T) and 25-hydroxyvitamin D [25(OH)D] were independent determinants of BMD in WOR infertile men (all p < 0.01) but not in fertile men. After stratifying Bio-T, WOR infertile men had lower BMD than fertile men (all p < 0.05) in low Bio-T subgroups (Bio-T ≤ 11.6 nmol/L), but not high Bio-T subgroups (Bio-T > 11.6 nmol/L). 25(OH)D was an independent determinant of sperm motility and morphology in WOR OATN men (all p < 0.05), with only borderline significance in fertile men(motility: p = 0.047; morphology: p = 0.056). T determined sperm concentration (square root) and morphology in WOR OATN men (all p < 0.001). No correlations between T and 25(OH)D were found in all groups. We suggest that infertile men have lower T and BMD than fertile men. 25(OH)D and T were associated with low BMD and poor semen quality in infertile men.

Severe oligozoospermia in a patient with myxedema coma

A case of severe oligozoospermia with myxedema coma is herein presented. The patient was referred to a male infertility clinic with a 5-year history of primary infertility. Decreased serum testosterone and elevated serum prolactin without abnormal MRI findings in the hypothalamus, and decreased semen volume and sperm motility were noted. A GnRH test revealed a decreased luteinizing hormone response, whereas the HCG test showed a normal testosterone increase. Because a urinalysis after ejaculation indicated retrograde ejaculation, imipramine administration was started. However, the semen quality deteriorated, so the patient was referred to an ART clinic. Twenty-one months from the initial visit, the patient developed a loss of consciousness and edema due to myxedema coma, a life-threatening state of hypothyroidism. The patient recovered after 1 month of thyroid hormone replacement therapy (HRT) with corticosteroids. Three months after the myxedema coma, a semen analysis showed a decreased semen volume (0.2 mL) and severe oligozoospermia (two spermatozoa/ejaculate). Elevated prolactin and decreased testosterone levels were still present. These parameters gradually improved after restoration of euthyroidism by HRT. In conclusion, physicians should confirm the thyroid function in the management of male infertility, especially in patients with elevated prolactin levels.

Focus issue on male infertility

Male infertility problems can occur when sperms are limited in number or function. In this paper, we describe the clinical evaluation of male infertility. A detailed history, physical examination, and basic semen analysis are required. In addition, ultrasound, karyotyping, and hormonal studies are needed to determine specific causes of infertility. In addition, the World Health Organization (WHO, 2009) has developed a manual to provide guidance in performing a comprehensive semen analysis. Among the possible reasons for male infertility, nonobstructive azoospermia is the least treatable, because few or no mature sperm may be produced. In many cases, men with nonobstructive azoospermia typically have small-volume testes and elevated FSH. Although treatment may not completely restore the quality of semen from men with subnormal fertility, in some cases a successful pregnancy can still be achieved through assisted reproductive technology.

Male reproductive health and prostate cancer risk

PURPOSE OF REVIEW

Male infertility impacts a substantial proportion of men and has serious implication for a man's quality of life. Advances in reproductive technology may allow men to bypass urologic care in order to achieve their family planning goals. Recent data suggests that male reproductive failure may be a harbinger of future urologic diseases, including prostate cancer (CaP), thus emphasizing the importance of dedicated urologic evaluation and care for all male infertility patients.

RECENT FINDINGS

We will review the epidemiologic data that explores an association between male reproductive health and CaP. We will review the potential biologic mechanisms that may underlie this association, and explore possible reasons for inconsistencies in study findings.

SUMMARY

Studies of the association between male infertility and CaP are inconsistent. Despite this, the association between reproductive health in a man's fourth decade (30s) and his development of aggressive CaP in his sixth decade (50s) should not be ignored. These findings, combined with the robustness of the potential common underlying mechanisms, provide a foundation for future studies of male reproductive health that are more specific in their approach to answering questions about the association between male reproductive failure and future systemic disease.

Use of diagnostic testing to detect infertility

The evaluation of the infertile male continues to be a clinical challenge of increasing significance with considerable emotional and financial burdens. Many physiological, environmental and genetic factors are implicated; however, the etiology of suboptimal semen quality is poorly understood. This review focuses on the diagnostic testing currently available, as well as future directions that will be helpful for the practicing urologist and other clinicians to fully evaluate the infertile male.

Contemporary concepts in the evaluation and management of male infertility

Infertility in men is a common condition. At the core of the medical evaluation of the male partner in a couple who are unable to conceive is the history and physical examination. Special attention should be directed to the patient's developmental history and any use of testosterone products. The physical examination focuses on the genitals, and includes assessments of the size and consistency of the testicles, epididymis, vas deferens, and presence of varicoceles. Although many sophisticated tests are available, semen analysis is still the most important diagnostic tool used to assess fertility, and includes parameters such as sperm count, motility and viability. Treatment of male factor infertility can involve targeted agents, in the case of specific conditions such as hypogonadotropic hypogonadism, or it can be empirical-using medical therapy or assisted conception techniques-for patients in whom no underlying cause has been identified. Although an all-encompassing treatment for male factor infertility has not yet been developed, the field offers many promising avenues of research.

An update on the clinical assessment of the infertile male. [corrected]

Male infertility is directly or indirectly responsible for 60% of cases involving reproductive-age couples with fertility-related issues. Nevertheless, the evaluation of male infertility is often underestimated or postponed. A coordinated evaluation of the infertile male using standardized procedures improves both diagnostic precision and the results of subsequent management in terms of effectiveness, risk and costs. Recent advances in assisted reproductive techniques (ART) have made it possible to identify and overcome previously untreatable causes of male infertility. To properly utilize the available techniques and improve clinical results, it is of the utmost importance that patients are adequately diagnosed and evaluated. Ideally, this initial assessment should also be affordable and accessible. We describe the main aspects of male infertility evaluation in a practical manner to provide information on the judicious use of available diagnostic tools and to better determine the etiology of the most adequate treatment for the existing condition.

Mendelian genetics of male infertility

Infertility is defined as the inability of a couple to conceive despite trying for a year, and it affects approximately 15% of the reproductive-age population. It is considered a genetically lethal factor, as the family lineage stops at that individual with no progeny produced. A genetic defect associated with an infertile individual cannot be transmitted to the offspring, ensuring the maintenance of reproductive fitness of the species. However, with the advent of assisted reproductive techniques (ART), we are now able to overcome sterility and bypass nature's protective mechanisms that developed through evolution to prevent fertilization by defective or deficient sperm.

Loss of the AZFc region due to a human Y-chromosome microdeletion in infertile male patients

Infertility is a major reproductive health threat; the frequency of male infertility due to Y-chromosome microdeletions is 13-18% in the human population; these microdeletions involve recurrent loss of three non-overlapping regions designated as AZFa, AZFb and AZFc, associated with spermatogenic failure. Several contradictory reports have been published regarding deletion frequency based on sequence-tagged site markers and genotype-phenotype correlation. We examined the prevalence of Yq- deletion in 64 clinically diagnosed infertile male patients. We found a 3% frequency of microdeletion of the AZFc region; hormone profiles (FSH, LH and testosterone) showed significantly (P < 0.001) elevated levels compared to controls. No mutations were observed in the AZFa and AZFb regions, perhaps due to the selective use of sequence-tagged site markers.

Differences in the clinical characteristics of primarily and secondarily infertile men with varicocele

OBJECTIVE

To compare the clinical characteristics of primarily and secondarily infertile men with varicocele.

DESIGN

Cross-sectional analysis.

SETTING

Male infertility clinic, tertiary health care center.

PATIENT(S)

Two hundred ninety-five infertile men with palpable varicoceles.

INTERVENTION(S)

Clinical evaluation including patient reproductive history (including assessment of primary or secondary infertility), physical examination, hormonal assessment and at least two semen analyses.

MAIN OUTCOME MEASURE(S)

Differences in the characteristics of men with primary vs. secondary infertility.

RESULT(S)

Two hundred five subjects were identified with primary infertility and 90 with secondary infertility. Secondarily infertile men were older (39.6 years vs. 35.0 years), with older partners (35.4 years vs. 33.2 years), but had higher sperm densities (51.3 vs. 36.0 million/mL) and a greater percentage of morphologically normal sperm (30.6% vs. 24.1%). A lower proportion of secondarily infertile men had total motile sperm count (TMC) <20 million compared with primarily infertile men (31.1% vs. 46.5%). Groups did not differ regarding infertility duration, tobacco or alcohol use, varicocele grade or laterality, testis volumes, or hormonal parameters. In multivariate modeling, secondary infertility (vs. primary) was an independent predictor of TMC >20 million (odds ratio 1.9).

CONCLUSION(S)

Men with secondary infertility are older and have older partners than primarily infertile men, yet they have significantly better sperm concentrations. Infertility in this group may be influenced by maternal reproductive potential.

Bilateral but not unilateral testicular hypotrophy predicts for severe impairment of semen quality in men with varicocele undergoing infertility evaluation

OBJECTIVES

Varicocele is a common cause of infertility, and varicocele-associated testicular hypotrophy has been described as a potential cause of decreased semen quality. We investigated the relationship between testicular hypotrophy and poor semen quality in infertile men with varicoceles. We hypothesized that bilateral hypotrophy is required before the semen quality is severely impaired.

METHODS

We retrospectively identified consecutive patients with palpable varicoceles undergoing an infertility evaluation at a single academic center. Each patient was evaluated by the same clinician with history and physical examination. Testicular hypotrophy was defined as a size discrepancy of greater than 3 mL or an absolute size of less than 14 mL. Multivariate logistic regression analysis was used to determine the clinical predictors of total motile sperm count (TMC) of less than 20 million.

RESULTS

A total of 245 men with complete data were identified, and 103 men with a TMC of less than 20 million sperm (mean age 36.2 +/- 6.6 years) were compared with 142 men with normal TMCs (mean age 37.1 +/- 6.5 years). On multivariate analysis, men with bilateral hypotrophy were nearly nine times more likely to have a TMC of less than 20 million sperm than were men without hypotrophy (odds ratio 8.8, 95% confidence interval 2.4 to 32.1), and six times more likely than those with unilateral hypotrophy (odds ratio 6.0, 95% confidence interval 1.4 to 26.3). Unilateral hypotrophy alone did not predict for a low TMC.

CONCLUSIONS

Among men with varicoceles undergoing infertility evaluation, those with bilateral hypotrophy are at the greatest risk of impaired semen quality.

Hormonal evaluation of the infertile male: has it evolved?

An endocrinologic evaluation of patients who have male-factor infertility has clearly evolved and leads to specific diagnoses and treatment strategies in a large population of infertile men. A well-considered endocrine evaluation is especially essential with the ever-growing popularity of assisted reproductive techniques and continued refinements with intracytoplasmic sperm injection.

Endocrine manipulation in male infertility

Endocrine therapy for male infertility is broadly categorized as specific or nonspecific therapy. Although uncommon, primary endocrine diagnoses in infertile men are amenable to targeted therapy. The efficacy of empiric endocrine therapy for idiopathic male infertility, however, has not been demonstrated conclusively by clinical trials. With better understanding of the underlying pathophysiology of idiopathic male infertility, careful evaluation of endocrine therapy in well-selected treatment groups and well-designed randomized, controlled trials is warranted. Although empiric endocrine therapy for idiopathic male infertility has been largely replaced by assisted reproductive techniques, both treatment modalities could play a role, perhaps as combination therapy.