Undescended testis in a full term, normal birth weight baby should be descended by age-6-months.
We now believe these testes should be brought down by age-1-year. Ex-preemies at 1 year. Some testes, thought to be retractile normal testes are later found to be undescended and should be corrected soon after discovery. Non-palpable testis in full-term new born will never spontaneously descend.