[Compensatory growth in children with intrauterine growth retardation of different etiologies].

Postnatal growth of infants born with low birth-weight for gestational age was studied by measuring monthly weight, supine length, head circumference and triceps skinfold from birth to seven months. Three groups were studied: twins (group A, N 15), babies with no apparent cause of their IGR; group B, N 20) and babies born from mothers with moderate to severe toxemia during pregnancy (group C, N 9). The three groups had a similar degree of birth-weight deficit, but birth-length was significantly more reduced in group C. The three groups presented some degree of catch-up-growth, reflected by a higher-than-average growth velocity, present during the first 3-4 months only; after this age, growth rates were not different from normal average. Groups A and B had a greater catch-up-growth than group C in weight and triceps skinfold, reaching 50th percentile in three months. Incomplete catch-up of group C may be due to interference of toxemic injury on critical period of fat cell replication. The prognosis of postnatal growth of babies with IGR is strongly dependent on the degree of catch-up-growth during the first months of extrauterine life; this is, in turn, related to the etiology responsible for IGR.