Short term growth in boys with delayed puberty after diagnostic human chorionic gonadotropin administration.

Using a sensitive measuring device, 3-day hCG administration (Pregnyl; 1500 IU daily) was shown to temporarily increase ulnar growth velocity from prepubertal (0.40 +/- 0.35 mm/3 weeks to pubertal values (1.1 +/- 0.64 mm/3 weeks) in 10 boys with delayed puberty. This growth-promoting effect of diagnostic hCG administration, which was demonstrable for 3--9 weeks, was associated with an overt rise in plasma testosterone from 129 +/- 126 to 818 +/- 419 ng/100 ml and an approximate doubling of the serum alkaline phosphatase activities from 193 +/- 46 to 376 +/- 115 U/liter, suggesting an initiated growth spurt.