The undescended testis in children and adolescents. Part 1: pathophysiology, classification, and fertility- and cancer-related controversies

This review examines undescended testis (UDT), affecting 3% of male newborns, focusing on pathophysiology and long-term risks including infertility and testicular cancer. Part 1 addresses controversies in understanding how failed testicular descent affects germ cell development and future reproductive health.