Japan's comprehensive undescended testis screening program: incidence of ascending testis after screening

This Japanese retrospective study of 376 boys demonstrates that comprehensive multi-stage screening for undescended testis from birth through age 3 significantly reduces the incidence of ascending testis and late surgical intervention compared to Western populations. The program achieved lower rates of surgery in boys ≥4 years (12.8% vs 30-50%) and ascending testis (5.7% vs 15.4%), suggesting early detection protocols effectively prevent testicular ascent after initial normal descent.