Aim: To determine factors before or at birth that are predictive of growth patterns to 18 months in children born small for gestational age (SGA).
Methods: Prospective cohort study of 186 SGA babies. Catch-up growth patterns were defined as early (>10th centile at 6 and 18 months), late (<10th centile at 6 months but >10th centile at 18 months), transient (>10th centile at 6 months but <10th centile at 18 months) or none (<10th centile at 6 and 18 months).
Results: Most children (75%) showed catch-up growth by 6 months. Of antenatal variables studied, only early gestation at diagnosis of SGA predicted late or failed catch-up. Late or failed catch-up was also associated with short gestation, small absolute and relative size at birth, increased placental weight/birthweight ratio (Pl/BW) and prolonged neonatal hospital stay. On logistic regression, both late and failed catch-up were associated with short birth length. Late catch-up growth was also associated with prolonged hospital stay and male sex. Failed catch-up was associated with increased Pl/BW. No antenatal or perinatal variables distinguished early from transient catch-up groups.
Conclusion: SGA babies with late onset and less severe growth restriction have a good chance of catch-up growth by 6 months of age. Catch-up growth is likely to be delayed in SGA babies who are short at birth, are boys, and have prolonged hospital stays. However, poor growth over the first 6 months does not predict later growth patterns. Failure of catch-up growth in babies with increased Pl/BW may reflect an intrinsic growth defect. Transient catch-up growth may reflect environmental factors operating after birth.