Infertility and Sexual Function
Core concepts
Understand male infertility evaluation (semen analysis, hormones, varicocele, obstruction) and sexual dysfunction (erectile dysfunction, Peyronie disease, ejaculatory disorders). Semen analysis parameters: volume, concentration, motility, morphology. Workup includes FSH, LH, testosterone, and karyotype/genetic testing when indicated (Klinefelter, Y-chromosome microdeletions). ED workup screens for vascular, neurogenic, hormonal, and psychogenic causes; PDE5 inhibitors are first-line, with contraindication to nitrates.
Traps
Azoospermia with low volume and low FSH suggests obstruction (or congenital absence of vas); high FSH suggests primary testicular failure. Do not prescribe testosterone to a man seeking fertility - it suppresses spermatogenesis. Peyronie disease with stable plaque may need surgery; acute phase is managed conservatively.
Worked example
A man with infertility, small testes, elevated FSH: primary testicular failure; karyotype to evaluate Klinefelter. If low volume ejaculate with absent vasa: suspect congenital bilateral absence of the vas deferens and test for CFTR.
Exam strategy
Hormone pattern (FSH/LH/testosterone) separates central from primary and obstructive from nonobstructive.