Most children born with low weight or intrauterine growth restriction develop catch-up growth that allows them to reach a final height according to their genetic target height. However, in about 15% of children this growth is insufficient. In both, children who have adequate compensatory growth and therefore normal height and children who remain low in childhood, it is necessary to take into account that if puberty starts early, the final height could be compromised. Timely and appropriate intervention could improve it. Control of body weight is also important, as an excessive gain in childhood is associated with metabolic complications in adolescence and adult life.