For a small number of children, reduced stature is a result of the failure of their bodies to produce naturally enough human growth hormone to allow normal growth. In 1958, doctors found a way to treat them with small amounts of the hormone, which was derived from the pituitary glands of cadavers.

The researchers surveyed pediatric endocrinologists -- the medical subspecialty most likely to treat short children -- and found that 40 percent of the patients receiving human growth hormone did not have a hormone deficiency. Some of those children, however, received human growth hormone for other diseases, such as Turner syndrome (underdeveloped gonads) or kidney insufficiency, in which there are known benefits.

While limited treatment with the hormone increased the rate of growth in short but otherwise normal children by between 40 percent and 90 percent, the researchers said in many cases the growth stopped when the children became adults and the treatment was stopped. In effect, while doses of growth hormone allowed them to be normal-sized as children, when they became older the growth stopped and they matured to become smaller-than-normal adults, perhaps no taller than they would have been if they had never taken the hormone treatments.