The relationship between intrauterine and postnatal growth on the subsequent psychomotor development of very low birthweight (VLBW) infants

Abstract

ABSTRACT. The aim of this study was to demonstrate the relationship between intrauterine and postnatal growth and subsequent neurological and intellectual development of very low birth weight (VLBW) infants. The effect of intrauterine growth was assessed by comparing the developmental outcomes of the 131 appropriate weight for gestational age (AGA) infants with the 33 small for gestational age (SGA) infants. No significant differences were found between the two groups with respect to head circumference, neurological, intellectual or sensory handicap rates. The mean General Quotient (GQ) at the last clinic assessment for the AGA infants was 101.2 and 97.2 for the SGA infants. The effect of extra‐uterine growth on subsequent development was assessed in the AGA and SGA infants separately, at the time of discharge and again at 12 months. The 31 AGA infants who failed to grow adequately in the nursery had more neonatal risk factors than the 100 AGA infants who continued to grow adequately after birth. This early postnatal growth failure was not predictive of developmental outcome. At 12 months of age, 26 infants (20%) who were initially appropriately grown at birth were failing to thrive. These infants had sustained more chronic diseases and caretaking disorders in the first year of life than their appropriately grown counterparts. They also had lower GQ and head circumference measurements (p<.05). The SGA infants who exhibited “catch up'’growth between birth and term had larger head circumference measurements at 1 year than those with persistent growth failure. Growth assessment at 12 months of age was not predictive of developmental outcome in SGA infants. We failed to show a relationship between intrauterine growth of VLBW infants and their subsequent development. AGA infants whose weights had dropped to the 3rd percentile by 12 months of age had a poorer outcome than their appropriately grown counterparts. Furthermore, early postnatal growth failure before term had no additional effects if catch up growth occurred thereafter. In the SGA group neither failure to reach the 3rd percentile by term or 12 months affected outcome.