The androgen receptor (AR) is part of a superfamily of nuclear receptors. The AR has a diverse set of downstream effects on male phenotype and sexual function, muscle mass and strength, bone density, hematopoiesis, cognition, and metabolism. Testosterone replacement therapy (TRT) to treat male hypogonadism utilizes exogenously administered testosterone to activate the AR. However, TRT is known to have potential risks, including erythrocytosis, dyslipidemia, prostatic hypertrophy, hepatotoxicity, impaired fertility, aromatization of testosterone to estrogen, and testicular atrophy. Selective androgen receptor modulators, also known as SARMs, are compounds that have shown tissue-selective activation of the AR. These compounds potentially offer the ability to treat hypogonadal conditions where activating the AR in the bone, muscle, or brain is desired while sparing undesired effects in tissues such as the prostate, liver, or bone marrow. Currently, there is a dearth of data in human subjects regarding the treatment of male hypogonadism with SARMs. However, from animal models and preliminary studies of SARMs in humans, there appears to be a possible role for SARMs in the hypogonadal man, and their efficacy and safety warrant further study.

The office evaluation of the infertile male involves a comprehensive history and physical structured to uncover all potential causes including congenital, medical, surgical, environmental, genetic, and psychosocial etiologies. The physical exam begins with the patient’s general appearance, body habitus, and progresses to the genital exam in which the testicles are examined for size, consistency, and location. Prior surgical scars, absence of the vas deferens, or the presence of varicoceles may be identifiable causes of infertility. The semen analysis is the cornerstone laboratory evaluation of the male undergoing an infertility workup. The semen is evaluated for several key parameters including volume as well as sperm concentration, number, motility, and form. An endocrine evaluation is indicated in men with oligospermia, azoospermia, or a history of physical examination findings suggestive of hormonal abnormalities including sexual dysfunction, decreased libido, or physical evidence of impair androgenization. Pending the initial workup genetic testing may be indicated.

More than one-third of American adults fail to achieve the 7–9 hours of sleep recommended by the American Academy of Sleep Medicine and the Sleep Research Society needed for optimal health and well-being. In addition to primary sleep disorders, such as sleep apnea, insomnia, and restless legs syndrome, many modern societal factors are also thought to contribute to chronic sleep deficiency, such as technology and work-related factors. Interruptions in the natural sleep–wake cycle can be associated with shift work and numerous chronic health conditions. A few studies have investigated the impact of nonstandard shift work on male reproductive health, and a compelling association between sleep and male urogenital health has been demonstrated. This chapter will review the literature on the effect of sleep and shift work on ED, LUTS, hypogonadism, male infertility, and how improved sleep quality can possibly improve common men’s health conditions.

Successful transportation of sperm from their origin within the seminiferous tubules of the testis to their site of emission in the posterior urethra involves a completely patent ductal system. Emerging from the testis into the efferent ducts, sperm enter 6–7 m of the coiled epididymal tubule, which develops into the convoluted vas deferens. The convoluted vas then gradually straightens as it courses up the scrotum, progressing first through the external ring of the inguinal canal, before diving into the retroperitoneum via the internal inguinal ring. Sperm within the vas will ultimately fill the widened ampulla of the vas and join with the seminal vesicle (SV) duct (approximately 2 cm in length) to form the ejaculatory duct (ED) that courses through the prostate. Obstruction can occur anywhere along this ductal system. This chapter will focus on the three most common sites of obstruction: the ED; the vas deferens; and the epididymis. The discussion will begin distally at the ED and progress proximally towards the testis.

The last and fourth edition of Infertility in the Male was published in 2009, and significant advances were realized in reproductive medicine and surgery in the intervening decade. In this edition, we have covered the more recent advances in the field while maintaining the core foundation of information needed for practitioners in diagnosing and treating the man seeking care for fertility. We have also endeavored to make the book more structured, and hopefully easier to use, for the student and specialist alike.