Human Chorionic Gonadotropin Test: Old Uncertainties, New Perspectives, and Value in 46,XY Disorders of Sex Development

The human chorionic gonadotropin (hCG) test represents a key step in assessing Leydig cell function in prepubertal males, but differences in terms of hCG doses, number of injections, and sequence of blood drawing are published in the literature, showing poor standardization. The few available data in healthy boys are summarized here. A recombinant hCG (rhCG) formulation might permit overcoming some controversies as well as avoid the potential biological risk related to the injection of extractive hormones. Studies in humans are scarce, but they indicate that 250 µg rhCG in a single dose may represent a useful scheme for the dynamic evaluation of Leydig cell function in children as well as in adults. The main indication for hCG testing in childhood is the investigation of 46,XY disorders of sex differentiation. The test must also be considered in order to investigate the presence of functional testicular tissue when gonadal peptide hormones cannot be measured.