How frequent is sterility following mumps infection? What you should tell your patients

Mumps virus infection can impair fertility in both sexes, though permanent sterility occurs far less frequently than transient testicular or ovarian inflammation. In post-pubertal males, mumps orchitis remains the most consequential complication. Approximately 15–30 % of adult males with mumps develop orchitis, and in 10–20 % of all infected men, it is bilateral. When both testes are affected, subsequent infertility (azoospermia or severe oligospermia) has been reported in 30–87 % of bilateral orchitis cases. Testicular atrophy develops in about 50 % of all orchitis cases, and overall impairment of fertility, ranging from reduced sperm count or motility to complete sterility, occurs in about 13–30 % of male patients. Unilateral orchitis seldom causes permanent sterility but may cause subfertility to be measurable years later by decreased sperm quality. The pathophysiology is linked to inflammation-induced damage of seminiferous tubules, ischemia within the tunica albuginea, and immune-mediated destruction of spermatogenic cells, leading to testicular...