Growth and growth hormone treatment in short stature children born small for gestational age

Abstract

Persistent short stature is one of the most frequent complications of being born small for gestational age (SGA) as almost 15% of such children have a low adult height. Additionally, individuals born SGA may have low lean body mass and increased central adiposity which put them at risk of long-term morbidity related to insulin resistance and metabolic disease. Onset of puberty appears at a normal age but comes relatively early for their actual height. There are studies that show that the pubertal growth spurt is moderately decreased in SGA and some girls may experience advanced pubarche and menarche. We have retrospectively analyzed 64 untreated SGA children and we have observed that adult height was lower than target height and positively correlated with maternal height, target height and height at onset of puberty; the tempo of puberty was very similar between SGA and controls but pubertal growth spurt was lower in SGA than in controls. The pathophysiology of postnatal growth failure is complex and different anomalies in the GH-IGF axis had been described. The effect of GH therapy on linear growth and adult height has been extensively studied in the last 15 years. In the short term, GH treatment produces an acceleration of growth with a significant increment of height which is dose dependent during the first 3-4 years. The long-term response is less dose dependent and the vast majority of short SGA children reach an adult height within normal standards and adequate for their target height. There is an important variation in the growth response of SGA children to GH indicating that SGA represents a heterogeneous condition in which response during the first year is the most important predictor of subsequent growth response. GH appears to be safe at the current doses employed but monitoring of IGF-I, IGFBP-3 and glucose metabolism is mandatory during therapy.