The aim of this study was to describe serum GH, IGF-I, and IGF binding protein (BP) 3 levels at birth and during the first 2 y of life in intrauterine growth-retarded (IUGR) children and to correlate these hormonal values with auxologic parameters noted during this period to investigate their predictive value on the postnatal growth pattern. Three hundred and seventeen children were included at birth and studied for auxologic and biologic parameters at birth, 3 and 30 d, and 3, 6, 12, 18, and 24 mo of age. At birth, when analyzed according to gestational age, serum GH levels were increased (p = 0.0001) and serum IGF-I and IGFBP3 levels were decreased (p = 0.0001) in IUGR as compared with normal neonates. When two cohorts were established at birth as a function of the ponderal index (PI) (< or = or > 3rd percentile), serum IGF-I and IGFBP3 levels were found to be significantly reduced in the case of low PI. All parameters were within normal limits at 1 mo of age and remained normal thereafter. During the first 3 mo of life, a positive correlation was found between IGF-I increment and weight gain (r = 0.28, p = 0.002). None of the biologic parameters at birth were predictive either of later growth or of short stature at 2 y of age. In conclusion, low serum IGF-I and IGFBP3 levels at birth were related to fetal malnutrition and were not predictive parameters for later growth.