Adult height of preterm infants: a longitudinal cohort study

Many infants born prematurely experience growth failure following delivery, with subsequent catch-up growth. Traditionally catch-up was thought to be complete in the first few years of life. Most studies have focused on groups of infants defined by birth weight, for example <1500 g, resulting in disproportionate numbers of small for gestational age infants. This study aimed to determine whether appropriate weight for gestation (AGA) preterm born children reach their expected adult height when compared with term controls.

This UK based prospective longitudinal cohort study recruited 204 preterm children born at a tertiary neonatal unit during 1994 and 50 matched controls. Growth parameters have been assessed annually until the completion of growth.

There was no significant difference in the final height SD score (SDS) of children born at term (n=30) and those born prematurely and AGA (n=70) (0.45 term vs 0.22 preterm). Catch-up growth however, continued throughout the whole of childhood. When the difference between final height SDS and mid-parental height SDS were compared, there were again no significant differences (0.13 term vs 0.03 preterm).

Those born prematurely with an AGA achieve a comparable adult height to children born at term, however, catch-up growth continues for much longer than traditionally thought.