Characteristics of Catch-Up Growth in Very Low Birth Weight Infants (<1500 g)

Abstract

Features of catch-up growth are not well established in very low birth weight infants (VLBW). The aim of this study is to analyze the catch-up growth in height and some factors associated in a cohort of VLBW (<1500 g) from birth to age 14 years. Retrospective registration of weight and height at birth and ages 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 14 years in a cohort of 170 VLBW have been recorded Anthropometric variables were compared with those from a control group. Sixty-nine (40.6%) were small for gestational age (SGA subgroup) and 101 (59.4%) were appropriate for gestational age (AGA subgroup). Thirty-seven (21.8%) were extremely low birth weight (ELBW), and 32 (18.8%) extremely preterm (EPT). At age 2, 4 and 10 years, 49.4%, 78.9% and 87.1% VLBW, respectively, did reach normal height. Between 4 and 10 years of age, only 8.2% of VLBW reached normal height. At 10 years of age, 7% of VLBW (1000–1500 g) and 35% of ELBW (<1500 g) showed short stature (p = 0.001). Almost the entire sample of VLBW with normal height at age 2, 4 and 10 have reached an adequate catch-up growth in weight in the previous evaluations. ELBW, SGA and EPT were found to be independent predictors for inadequate catch-up growth in height at 2, 4, and 10 years of age. The growth pattern of children born preterm has particular features: they have a lower rate and/or slowness in the catch-up growth in height with respect to that described in full-term small-for-gestational-age infants. Catch-up in weight appears to be a decisive factor for catch-up in height, and, on this basis, we recommend a rigorous nutritional follow-up in these individuals. If these measures do not help improve catch-up in height, they may be eligible for the establishment of rhGH therapy.