De niet-scrotale testis: argumenten vóór vroeg behandelen, mits retractiele testis en verworven niet-scrotale testis zijn uitgesloten

--Guidelines for the treatment ofundescended testis (UDT) are sparse. Often an operation in the second year of life is advised. --Recent data indicate that the normal maturation process, which will ultimately lead to a normal quantity and quality of germ cells, is impaired as early as in the first half year of a newborn's life. None of the guidelines take this into account. Spontaneous descent after the fourth month following birth, of testes that have previously not descended, hardly ever occurs. --No differences have been shown in complication numbers between surgery before and after the first birthday. Orchidopexy prior to the 13th birthday reduces the risk of testicular cancer. --Therefore, based on these data, it is advised to perform orchidopexy in the second half of the first year of a newborn's life. In older boys a UDT must be treated before the 13th birthday. --In the Netherlands a lot more orchidopexies are done despite what may be expected based on prevalence numbers of UDT: testes retaining a normal volume that would most probably have descended spontaneously come puberty. --It remains important to carry out a careful physical examination and document the position of the testes soon after birth, and later on if UDT is suspected, to avoid unnecessary operations on retractile testes and acquired UDT