Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline Part I.

PURPOSE: The summary presented herein represents Part I of the two-part series dedicated to the Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline. Part I outlines the appropriate evaluation of the male in an infertile couple. Recommendations proceed from obtaining an appropriate history and physical exam (Appendix I), as well as diagnostic testing, where indicated. MATERIALS/METHODS: The Emergency Care Research Institute Evidence-based Practice Center team searched PubMed®, Embase®, and Medline from January, 2000 through May, 2019. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (table 1[Table: see text]). This summary is being simultaneously published in Fertility and Sterility and The Journal of Urology. RESULTS: This Guideline provides updated, evidence-based recommendations regarding evaluation of male infertility as well as the association of male infertility with other important health conditions. The detection of male infertility increases the risk of subsequent development of health problems for men. In addition, specific medical conditions are associated with some causes for male infertility. Evaluation and treatment recommendations are summarized in the associated algorithm (figure[Figure: see text]). CONCLUSION: The presence of male infertility is crucial to the health of patients and its effects must be considered for the welfare of society. This document will undergo updating as the knowledge regarding current treatments and future treatment options continues to expand.

Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline PART II.

PURPOSE: The summary presented herein represents Part II of the two-part series dedicated to the Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline. Part II outlines the appropriate management of the male in an infertile couple. Medical therapies, surgical techniques, as well as use of intrauterine insemination (IUI)/in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) are covered to allow for optimal patient management. Please refer to Part I for discussion on evaluation of the infertile male and discussion of relevant health conditions that are associated with male infertility. MATERIALS/METHODS: The Emergency Care Research Institute Evidence-based Practice Center team searched PubMed®, Embase®, and Medline from January 2000 through May 2019. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (table[Table: see text]). This summary is being simultaneously published in Fertility and Sterility and The Journal of Urology. RESULTS: This Guideline provides updated, evidence-based recommendations regarding management of male infertility. Such recommendations are summarized in the associated algorithm (figure[Figure: see text]). CONCLUSION: Male contributions to infertility are prevalent, and specific treatment as well as assisted reproductive techniques are effective at managing male infertility. This document will undergo additional literature reviews and updating as the knowledge regarding current treatments and future treatment options continues to expand.

Diagnosis and treatment of infertility in men: AUA/ASRM guideline part II.

PURPOSE: The summary presented herein represents Part II of the two-part series dedicated to the Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline. Part II outlines the appropriate management of the male in an infertile couple. Medical therapies, surgical techniques, as well as use of intrauterine insemination (IUI)/in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) are covered to allow for optimal patient management. Please refer to Part I for discussion on evaluation of the infertile male and discussion of relevant health conditions that are associated with male infertility. MATERIALS/METHODS: The Emergency Care Research Institute Evidence-based Practice Center team searched PubMed®, Embase®, and Medline from January 2000 through May 2019. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions. (Table 1) This summary is being simultaneously published in Fertility and Sterility and The Journal of Urology. RESULTS: This Guideline provides updated, evidence-based recommendations regarding management of male infertility. Such recommendations are summarized in the associated algorithm. (Figure 1) CONCLUSION: Male contributions to infertility are prevalent, and specific treatment as well as assisted reproductive techniques are effective at managing male infertility. This document will undergo additional literature reviews and updating as the knowledge regarding current treatments and future treatment options continues to expand.

Diagnosis and treatment of infertility in men: AUA/ASRM guideline part I.

PURPOSE: The summary presented herein represents Part I of the two-part series dedicated to the Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline. Part I outlines the appropriate evaluation of the male in an infertile couple. Recommendations proceed from obtaining an appropriate history and physical exam (Appendix I), as well as diagnostic testing, where indicated. MATERIALS/METHODS: The Emergency Care Research Institute Evidence-based Practice Center team searched PubMed®, Embase®, and Medline from January, 2000 through May, 2019. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions. (Table 1) This summary is being simultaneously published in Fertility and Sterility and The Journal of Urology. RESULTS: This Guideline provides updated, evidence-based recommendations regarding evaluation of male infertility as well as the association of male infertility with other important health conditions. The detection of male infertility increases the risk of subsequent development of health problems for men. In addition, specific medical conditions are associated with some causes for male infertility. Evaluation and treatment recommendations are summarized in the associated algorithm. (Figure 1) CONCLUSION: The presence of male infertility is crucial to the health of patients and its effects must be considered for the welfare of society. This document will undergo updating as the knowledge regarding current treatments and future treatment options continues to expand.

Fertility in Adolescents With Klinefelter Syndrome: A Survey of Current Clinical Practice.

CONTEXT: Progress has been made in determining the fertility timeline and potential in adolescents with Klinefelter syndrome; however, medical professionals are currently without protocols to guide treatment. OBJECTIVE: To evaluate the current practices regarding fertility and andrology care in adolescent males with Klinefelter syndrome. DESIGN: A 24-question survey was developed to elicit practitioner background/expertise and management practices. This was distributed to members of the Society for the Study of Male Reproduction, the Pediatric Endocrine Society, and the Endocrine Society. SETTING: N/A. PATIENTS: Adolescent males with Klinefelter syndrome. INTERVENTION: None. MAIN OUTCOME MEASURED: Current practices regarding fertility and andrology care. RESULTS: 232 responses were received from 133 (57%) adult endocrinologists, 60 (26%) pediatric endocrinologists, and 39 (17%) urologists. Among these, 69% of respondents were in academics, 62% practiced for > 10 years, and 65% received formal training in Klinefelter syndrome. All specialties encouraged sperm banking in late puberty, however most disagreed with the practice in early puberty. Seventy-eight percent agreed that testicular biopsy should be offered if no sperm was found in the ejaculate. The perceived optimal age for testicular biopsy varied among specialists. Clinical symptoms of hypogonadism (28%), rising gonadotropin levels (15%), and testosterone levels (15%) were the most commonly cited reasons for initiation of testosterone replacement therapy. CONCLUSION: Fertility preservation practices in adolescents with Klinefelter syndrome vary greatly within and among the specialties caring for these patients. These findings should guide future research and highlight the importance of establishing clinical practice guidelines.

The International Glossary on Infertility and Fertility Care, 2017.

STUDY QUESTION: Can a consensus and evidence-driven set of terms and definitions be generated to be used globally in order to ensure consistency when reporting on infertility issues and fertility care interventions, as well as to harmonize communication among the medical and scientific communities, policy-makers, and lay public including individuals and couples experiencing fertility problems? SUMMARY ANSWER: A set of 283 consensus-based and evidence-driven terminologies used in infertility and fertility care has been generated through an inclusive consensus-based process with multiple stakeholders. WHAT IS KNOWN ALREADY: In 2006 the International Committee for Monitoring Assisted Reproductive Technologies (ICMART) published a first glossary of 53 terms and definitions. In 2009 ICMART together with WHO published a revised version expanded to 87 terms, which defined infertility as a disease of the reproductive system, and increased standardization of fertility treatment terminology. Since 2009, limitations were identified in several areas and enhancements were suggested for the glossary, especially concerning male factor, demography, epidemiology and public health issues. STUDY DESIGN, SIZE, DURATION: Twenty-five professionals, from all parts of the world and representing their expertise in a variety of sub-specialties, were organized into five working groups: clinical definitions; outcome measurements; embryology laboratory; clinical and laboratory andrology; and epidemiology and public health. Assessment for revisions, as well as expansion on topics not covered by the previous glossary, were undertaken. A larger group of independent experts and representatives from collaborating organizations further discussed and assisted in refining all terms and definitions. PARTICIPANTS/MATERIALS, SETTING, METHODS: Members of the working groups and glossary co-ordinators interacted through electronic mail and face-to-face in international/regional conferences. Two formal meetings were held in Geneva, Switzerland, with a final consensus meeting including independent experts as well as observers and representatives of international/regional scientific and patient organizations. MAIN RESULTS AND THE ROLE OF CHANCE: A consensus-based and evidence-driven set of 283 terminologies used in infertility and fertility care was generated to harmonize communication among health professionals and scientists as well as the lay public, patients and policy makers. Definitions such as 'fertility care' and 'fertility awareness' together with terminologies used in embryology and andrology have been introduced in the glossary for the first time. Furthermore, the definition of 'infertility' has been expanded in order to cover a wider spectrum of conditions affecting the capacity of individuals and couples to reproduce. The definition of infertility remains as a disease characterized by the failure to establish a clinical pregnancy; however, it also acknowledges that the failure to become pregnant does not always result from a disease, and therefore introduces the concept of an impairment of function which can lead to a disability. Additionally, subfertility is now redundant, being replaced by the term infertility so as to standardize the definition and avoid confusion. LIMITATIONS, REASONS FOR CAUTION: All stakeholders agreed to the vast majority of terminologies included in this glossary. In cases where disagreements were not resolved, the final decision was reached after a vote, defined before the meeting as consensus if passed with 75%. Over the following months, an external expert group, which included representatives from non-governmental organizations, reviewed and provided final feedback on the glossary. WIDER IMPLICATIONS OF THE FINDINGS: Some terminologies have different definitions, depending on the area of medicine, for example demographic or clinical as well as geographic differences. These differences were taken into account and this glossary represents a multinational effort to harmonize terminologies that should be used worldwide. STUDY FUNDING/COMPETING INTERESTS: None. TRIAL REGISTRATION NUMBER: N/A.

The diagnosis of male infertility: an analysis of the evidence to support the development of global WHO guidance-challenges and future research opportunities.

BACKGROUND: Herein, we describe the consensus guideline methodology, summarize the evidence-based recommendations we provided to the World Health Organization (WHO) for their consideration in the development of global guidance and present a narrative review of the diagnosis of male infertility as related to the eight prioritized (problem or population (P), intervention (I), comparison (C) and outcome(s) (O) (PICO)) questions. Additionally, we discuss the challenges and research gaps identified during the synthesis of this evidence. OBJECTIVE AND RATIONALE: The aim of this paper is to present an evidence-based approach for the diagnosis of male infertility as related to the eight prioritized PICO questions. SEARCH METHODS: Collating the evidence to support providing recommendations involved a collaborative process as developed by WHO, namely: identification of priority questions and critical outcomes; retrieval of up-to-date evidence and existing guidelines; assessment and synthesis of the evidence; and the formulation of draft recommendations to be used for reaching consensus with a wide range of global stakeholders. For each draft recommendation the quality of the supporting evidence was then graded and assessed for consideration during a WHO consensus. OUTCOMES: Evidence was synthesized and recommendations were drafted to address the diagnosis of male infertility specifically encompassing the following: What is the prevalence of male infertility and what proportion of infertility is attributable to the male? Is it necessary for all infertile men to undergo a thorough evaluation? What is the clinical (ART/non ART) value of traditional semen parameters? What key male lifestyle factors impact on fertility (focusing on obesity, heat and tobacco smoking)? Do supplementary oral antioxidants or herbal therapies significantly influence fertility outcomes for infertile men? What are the evidence-based criteria for genetic screening of infertile men? How does a history of neoplasia and related treatments in the male impact on (his and his partner's) reproductive health and fertility options? And lastly, what is the impact of varicocele on male fertility and does correction of varicocele improve semen parameters and/or fertility? WIDER IMPLICATIONS: This evidence synthesis analysis has been conducted in a manner to be considered for global applicability for the diagnosis of male infertility.

The International Glossary on Infertility and Fertility Care, 2017.

STUDY QUESTION: Can a consensus and evidence-driven set of terms and definitions be generated to be used globally in order to ensure consistency when reporting on infertility issues and fertility care interventions, as well as to harmonize communication among the medical and scientific communities, policy-makers, and lay public including individuals and couples experiencing fertility problems? SUMMARY ANSWER: A set of 283 consensus-based and evidence-driven terminologies used in infertility and fertility care has been generated through an inclusive consensus-based process with multiple stakeholders. WHAT IS KNOWN ALREADY: In 2006 the International Committee for Monitoring Assisted Reproductive Technologies (ICMART) published a first glossary of 53 terms and definitions. In 2009 ICMART together with WHO published a revised version expanded to 87 terms, which defined infertility as a disease of the reproductive system, and increased standardization of fertility treatment terminology. Since 2009, limitations were identified in several areas and enhancements were suggested for the glossary, especially concerning male factor, demography, epidemiology and public health issues. STUDY DESIGN, SIZE, DURATION: Twenty-five professionals, from all parts of the world and representing their expertise in a variety of sub-specialties, were organized into five working groups: clinical definitions; outcome measurements; embryology laboratory; clinical and laboratory andrology; and epidemiology and public health. Assessment for revisions, as well as expansion on topics not covered by the previous glossary, were undertaken. A larger group of independent experts and representatives from collaborating organizations further discussed and assisted in refining all terms and definitions. PARTICIPANTS/MATERIALS, SETTING, METHODS: Members of the working groups and glossary co-ordinators interacted through electronic mail and face-to-face in international/regional conferences. Two formal meetings were held in Geneva, Switzerland, with a final consensus meeting including independent experts as well as observers and representatives of international/regional scientific and patient organizations. MAIN RESULTS AND THE ROLE OF CHANCE: A consensus-based and evidence-driven set of 283 terminologies used in infertility and fertility care was generated to harmonize communication among health professionals and scientists as well as the lay public, patients and policy makers. Definitions such as 'fertility care' and 'fertility awareness' together with terminologies used in embryology and andrology have been introduced in the glossary for the first time. Furthermore, the definition of 'infertility' has been expanded in order to cover a wider spectrum of conditions affecting the capacity of individuals and couples to reproduce. The definition of infertility remains as a disease characterized by the failure to establish a clinical pregnancy; however, it also acknowledges that the failure to become pregnant does not always result from a disease, and therefore introduces the concept of an impairment of function which can lead to a disability. Additionally, subfertility is now redundant, being replaced by the term infertility so as to standardize the definition and avoid confusion. LIMITATIONS, REASONS FOR CAUTION: All stakeholders agreed to the vast majority of terminologies included in this glossary. In cases where disagreements were not resolved, the final decision was reached after a vote, defined before the meeting as consensus if passed with 75%. Over the following months, an external expert group, which included representatives from non-governmental organizations, reviewed and provided final feedback on the glossary. WIDER IMPLICATIONS OF THE FINDINGS: Some terminologies have different definitions, depending on the area of medicine, for example demographic or clinical as well as geographic differences. These differences were taken into account and this glossary represents a multinational effort to harmonize terminologies that should be used worldwide. STUDY FUNDING/COMPETING INTERESTS: None. TRIAL REGISTRATION NUMBER: N/A.

Introduction: Access to fertility care.

Given that only an estimated 24% of infertile couples in the United States can fully engage in the medical care required to successfully conceive, the American Society for Reproductive Medicine (ASRM) has incorporated improved access to the full gamut of fertility therapies as an integral component of the Society's strategic plan that was launched in 2014. Toward this end, the ASRM hosted a two-day summit held in Washington D.C. in September 2015 that attracted thought leaders, both speakers and attendees, from around the world. This issue's Views and Reviews focuses on several key areas integral to this effort: an appreciation of the economic challenges to access, as well as the impact and interplay of racial, ethnic, emotional and gender-specific issues in the treatment of infertility. The potential to broaden access to care through modification of existing assisted reproductive techniques is also explored.

It's not all about the testes: medical issues in Klinefelter patients.

Important medical conditions associated with Klinefelter syndrome (KS) are categorized as: 1) motor, cognitive, and behavioral dysfunction; 2) tumors; 3) vascular disease; and 4) endocrine/metabolic and autoimmune diseases. Earlier diagnosis of KS may lead to earlier intervention with effective treatment.

Repeated assessment by high-throughput assay demonstrates that sperm DNA methylation levels are highly reproducible.

OBJECTIVE: To assess reliability of a high-throughput assay of sperm DNA methylation. DESIGN: Observational study comparing DNA methylation of sperm isolated from 3 divided and 12 longitudinally collected semen samples. SETTING: Academic medical center. PATIENT(S): One man undergoing screening semen analysis during evaluation of an infertile couple and 2 healthy fertile male volunteers. INTERVENTION(S): Spermatozoa were separated from seminal plasma and somatic cells using gradient separation. DNA was extracted from spermatozoa, and DNA methylation was assessed at 1,505 DNA sequence-specific sites. MAIN OUTCOME MEASURE(S): Repeatability of sperm DNA methylation measures, estimated by correlation coefficients. RESULT(S): DNA methylation levels were highly correlated within matched sets of divided samples (all r ≥ 0.97) and longitudinal samples (average r = 0.97). CONCLUSION(S): The described methodology reliably assessed methylation of sperm DNA at large numbers of sites. Methylation profiles were consistent over time. High-throughput assessment of sperm DNA methylation is a promising tool for studying the role of epigenetic state in male fertility.

The ups and downs of mutation frequencies during aging can account for the Apert syndrome paternal age effect.

Apert syndrome is almost always caused by a spontaneous mutation of paternal origin in one of two nucleotides in the fibroblast growth factor receptor 2 gene (FGFR2). The incidence of this disease increases with the age of the father (paternal age effect), and this increase is greater than what would be expected based on the greater number of germ-line divisions in older men. We use a highly sensitive PCR assay to measure the frequencies of the two causal mutations in the sperm of over 300 normal donors with a wide range of ages. The mutation frequencies increase with the age of the sperm donors, and this increase is consistent with the increase in the incidence rate. In both the sperm data and the birth data, the increase is non-monotonic. Further, after normalizing for age, the two Apert syndrome mutation frequencies are correlated within individual sperm donors. We consider a mathematical model for germ-line mutation which reproduces many of the attributes of the data. This model, with other evidence, suggests that part of the increase in both the sperm data and the birth data is due to selection for mutated premeiotic cells. It is likely that a number of other genetic diseases have similar features.

Endocrinology of male infertility: evaluation and treatment.

A normal functioning reproductive endocrine system is a prerequisite for normal male fertility. Any disruption of the delicately coordinated interaction between the components of the hypothalamic-pituitary-testicular axis may lead to hypogonadism and/or infertility. The goal of the clinical evaluation is to determine if the patient has an abnormality of testosterone production or action, the etiology of the abnormality, and if hormone therapy will correct the infertility. Based on a careful history, physical examination, and evaluation of the hormones of the reproductive axis, the physician will ascertain if the patient's hypogonadism is (1) prepubertal or postpubertal in onset; (2) the result of an abnormality in the hypothalamic-pituitary axis, the testes, or the androgen receptor; or (3) associated with another underlying medical condition. This information will place the patient into one of four diagnostic categories: hypogonadotropic hypogonadism, testicular failure, 5alpha-reductase deficiency, or androgen resistance. Within each category are disorders with identifiable pathogenic mechanisms. Recent studies have added to these lists and have provided insights into the molecular basis and inheritance patterns of several of these endocrinopathies.

Science linking environmental contaminant exposures with fertility and reproductive health impacts in the adult male.

In the field of reproductive environmental health there remain many unanswered questions regarding the impact of the environment on male reproductive health. Suggested needs include studies that target populations with high exposure to chemicals, including phthalates and bisphenol A. We also need to identify susceptibility factors and critical exposure windows (life stages) that may increase a man's risk of infertility. Finally, we need to develop methods to better study mixtures of chemicals and develop methods to assess clinical reproductive outcomes of human exposure to the ever-growing list of chemicals.

Widespread epigenetic abnormalities suggest a broad DNA methylation erasure defect in abnormal human sperm.

BACKGROUND: Male-factor infertility is a common condition, and etiology is unknown for a high proportion of cases. Abnormal epigenetic programming of the germline is proposed as a possible mechanism compromising spermatogenesis of some men currently diagnosed with idiopathic infertility. During germ cell maturation and gametogenesis, cells of the germ line undergo extensive epigenetic reprogramming. This process involves widespread erasure of somatic-like patterns of DNA methylation followed by establishment of sex-specific patterns by de novo DNA methylation. Incomplete reprogramming of the male germ line could, in theory, result in both altered sperm DNA methylation and compromised spermatogenesis. METHODOLOGY/PRINCIPAL FINDING: We determined concentration, motility and morphology of sperm in semen samples collected by male members of couples attending an infertility clinic. Using MethyLight and Illumina assays we measured methylation of DNA isolated from purified sperm from the same samples. Methylation at numerous sequences was elevated in DNA from poor quality sperm. CONCLUSIONS: This is the first report of a broad epigenetic defect associated with abnormal semen parameters. Our results suggest that the underlying mechanism for these epigenetic changes may be improper erasure of DNA methylation during epigenetic reprogramming of the male germ line.

Male infertility and variation in CAG repeat length in the androgen receptor gene: a meta-analysis.

CONTEXT: Many studies have investigated the association between male infertility and trinucleotide repeat polymorphisms in the androgen receptor (AR) gene, but no comprehensive meta-analysis of all published studies has been conducted. OBJECTIVE: Our goals were to summarize published data on associations between AR CAG and GGC repeat lengths and male infertility and investigate sources of variation between study results. DATA SOURCES: We searched for reports published before October 2006 using Medline, PubMed, and Web of Science. STUDY SELECTION: All selected studies included the following: a case group with infertility as measured by semen parameters, a control group of known or presumed fertile men, and measurement of CAG and/or GGC repeat lengths among cases and controls. Thirty-nine reports were selected based on these criteria, and 33 were ultimately included in the meta-analysis. DATA EXTRACTION: One investigator extracted data on sample size, mean and sd of trinucleotide repeat length, and study characteristics. DATA SYNTHESIS: Estimates of the standardized mean difference (95% confidence interval) were 0.19 (0.09-0.29) for the 33 studies and 0.31 (0.14-0.47) for a subset of 13 studies that used more stringent case and control selection criteria. Thus, in both groups, cases had statistically significantly longer CAG repeat length than controls. Publication date appeared to be a significant source of variation between studies. CONCLUSIONS: This meta-analysis provides support for an association between increased androgen receptor CAG length and idiopathic male infertility, suggesting that even subtle disruptions in the androgen axis may compromise male fertility.

Voltage-dependent calcium channels in mammalian spermatozoa revisited.

The last few years have seen an explosion in the number of voltage-dependent ion channel sequences detected in sperm and testes. The complex structural paradigm of these channels is now known to include a pore-forming alpha1 subunit(s) whose electrophysiological properties are modulated by an intracellular beta subunit, a disulfide-linked complex of a membrane-spanning delta subunit with an extracellular alpha2 subunit, and a transmembrane gamma subunit. Many of these are alternatively spliced. Furthermore, the known number of genes coding each subtype has expanded significantly (10 alpha1, 4 beta, 4 alpha2delta, 8 gamma). Recently, the CatSper gene family has been characterized based on similarity to the voltage-dependent calcium channel alpha1 subunit. From among this multiplicity, a wide cross-section is active in sperm, including many splice variants. For example, expression of the various alpha1 subunits appears strictly localized in discrete domains of mature sperm, and seems to control distinct physiological roles such as cellular signaling pathways. These include alpha1 alternative splicing variants that are regulated by ions passed by channels in developing sperm. Various combinations of ion channel sequence variants have been studies in research models and in a variety of human diseases, including male infertility. For example, rats that are genetically resistant to testes damage by lead seem to respond to lead ions by increasing alpha1 alternative splicing. In contrast, in varicocele-associated male infertility, the outcome from surgical correction correlates with suppression of alpha1 alternative splicing, Ion channel blockers remain attractive model contraceptive drugs because of their ability to modulate cholesterol levels. However, the large number of sperm ion channel variants shared with other cell types make ion channels less attractive targets for male contraceptive development than a few years ago. In this review, the genetics, structure and function of voltage-dependent calcium channels and related CatSper molecules will be discussed, and several practical clinical applications associated with these channels will be reported.

Etiology of azoospermia in a large nonreferral inner-city population.

A higher proportion of nonobstructive than obstructive azoospermia, as well as an increased prevalence of hypogonadotropic hypogonadism were documented in a retrospective study characterizing azoospermia in a population of predominantly Latino, inner-city male partners of infertile couples, as compared to previous reports from relatively affluent socioeconomic status male populations.

High-resolution recombination patterns in a region of human chromosome 21 measured by sperm typing.

For decades, classical crossover studies and linkage disequilibrium (LD) analysis of genomic regions suggested that human meiotic crossovers may not be randomly distributed along chromosomes but are focused instead in "hot spots." Recent sperm typing studies provided data at very high resolution and accuracy that defined the physical limits of a number of hot spots. The data were also used to test whether patterns of LD can predict hot spot locations. These sperm typing studies focused on several small regions of the genome already known or suspected of containing a hot spot based on the presence of LD breakdown or previous experimental evidence of hot spot activity. Comparable data on target regions not specifically chosen using these two criteria is lacking but is needed to make an unbiased test of whether LD data alone can accurately predict active hot spots. We used sperm typing to estimate recombination in 17 almost contiguous ~5 kb intervals spanning 103 kb of human Chromosome 21. We found two intervals that contained new hot spots. The comparison of our data with recombination rates predicted by statistical analyses of LD showed that, overall, the two datasets corresponded well, except for one predicted hot spot that showed little crossing over. This study doubles the experimental data on recombination in men at the highest resolution and accuracy and supports the emerging genome-wide picture that recombination is localized in small regions separated by cold areas. Detailed study of one of the new hot spots revealed a sperm donor with a decrease in recombination intensity at the canonical recombination site but an increase in crossover activity nearby. This unique finding suggests that the position and intensity of hot spots may evolve by means of a concerted mechanism that maintains the overall recombination intensity in the region.

Exposure to environmental ozone alters semen quality.

Idiopathic male infertility may be due to exposure to environmental toxicants that alter spermatogenesis or sperm function. We studied the relationship between air pollutant levels and semen quality over a 2-year period in Los Angeles, California, by analyzing repeated semen samples collected by sperm donors. Semen analysis data derived from 5,134 semen samples from a sperm donor bank were correlated with air pollutant levels (ozone, nitrogen dioxide, carbon monoxide, and particulate matter < 10 microm in aerodynamic diameter) measured 0-9, 10-14, and 70-90 days before semen collection dates in Los Angeles between January 1996 and December 1998. A linear mixed-effects model was used to model average sperm concentration and total motile sperm count for the donation from each subject. Changes were analyzed in relationship to biologically relevant time points during spermatogenesis, 0-9, 10-14, and 70-90 days before the day of semen collection. We estimated temperature and seasonality effects after adjusting for a base model, which included donor's date of birth and age at donation. Forty-eight donors from Los Angeles were included as subjects. Donors were included if they collected repeated semen samples over a 12-month period between January 1996 and December 1998. There was a significant negative correlation between ozone levels at 0-9, 10-14, and 70-90 days before donation and average sperm concentration, which was maintained after correction for donor's birth date, age at donation, temperature, and seasonality (p < 0.01). No other pollutant measures were significantly associated with sperm quality outcomes. Exposure to ambient ozone levels adversely affects semen quality.