Catch-up growth and supine length/height in very low birth weight, small for gestational age preterm infants: Results of a longitudinal study from birth to adulthood

Abstract

Linear growth of very low birth weight (VLBW) small for gestational age (SGA; < 10th percentile) preterm infants was analyzed from birth to adult age as to catch-up or no catch-up growth. These VLBW SGA preterm infants (n =46) with primarily symmetric intrauterine growth restriction from the Bonn Longitudinal Study were compared with 62 appropriate for gestational age (AGA) VLBW preterm and 73 term infants and with their parents. Forty-six percent of VLBW SGA (21 of 46) had complete height catch-up by adult age, and most became taller than target height (TH; 15 of 21; 71%). The other 25 did not catch up (54%); most of them remained shorter than TH (18 of 25; 72%) after initial catch-up followed by catch-down growth. Their mean adult height z-score was lower than that for birth length. Mean body mass index was similar in the catch-up and no catch-up groups (21.8 and 21.3, respectively) and lower than in the controls (23.2). Approximately half of the head circumference (HC) catch-up children achieved height catch-up as well. Height catch-up extended beyond age 6 years up to adult age; it was independent of HC growth (i.e., catch-up or not). Growth of the VLBW SGA preterm infants was characterized by its great heterogeneity and intraindividual variability. Height catch-down or successful catch-up growth could not be predicted.