Short-term benefits of catch-up growth for small-for-gestational-age infants

Background. Recent studies suggest that small newborns who present rapid postnatal growth may have an increased risk of chronic diseases in adulthood. On the other hand, it is widely assumed that catch-up growth is desirable for low birthweight children, but the literature on this subject is limited. Methods. Population-based cohort study in southern Brazil, with 3582 children examined at birth, 20 and 42 months of age. Catch-up growth from 0 to 20 months was related to subsequent risks of hospital admissions and mortality. Results. Children who were small-for-gestational-age (SGA) but presented substantial weight gain (≥0.66 z-score) up to the age of 20 months had 65% fewer subsequent hospital admissions than other SGA children (5.6% versus 16.0%; P <0.001). Mortality to age 5 years was 75% lower (3 versus 13 per 1000, a non-significant difference based on a small number of deaths) for rapid-growing SGA children compared to the remaining SGA children. Their admission and mortality rates were similar to those observed for children born with an appropriate birthweight for their gestational age (AGA). Similar positive effects of rapid growth were found for AGA children. Conclusion. There appear to be definite benefits associated with catch-up growth. Growth promotion efforts for infants who are born small should take into account their possible short- and long-term consequences.