Clinical diagnosis of cryptorchidism. John Radcliffe Hospital Cryptorchidism Study Group.

We examined 3534 boys for cryptorchidism at birth, and, if present, again at 3 months of age. We compared Scorer's standard criterion for cryptorchidism, based on measurement of the testis from the public tubercle, with the simpler criterion of whether the testis was in the normal position, well down in the scrotum. At birth 210 (5.9%) boys were cryptorchid by measurement and 220 (6.2%) by position. By 3 months of age the cryptorchidism rate was identical (1.6%) whichever criterion was used. We therefore recommend that position be used as the sole criterion for diagnosing cryptorchidism. There was a clear decrease in the cryptorchidism rate with increasing birth weight. A testis that was undescended at birth was more likely to descend spontaneously by 3 months the lower its position along the normal pathway of descent. For a given position of the testis, cryptorchid babies weighing less than 2500 g had a greater chance of spontaneous descent by 3 months than larger babies. An independent effect of gestation is suggested; cryptorchid babies of less than 37 weeks' gestation were more likely to have normally descended testes at 3 months than babies of longer gestation.