Postnatal growth failure in preterm infants: ascertainment and relation to long-term outcome

OBJECTIVE: Traditional measure of postnatal growth failure assessment has poor discriminatory power for long-term outcomes. Our objective was to identify measure of postnatal growth failure associated with long-term outcome in preterm infants born at < 28 weeks' gestation. PATIENTS AND METHODS: Four measures of defining postnatal growth failure at 36 weeks corrected gestational age: (1) weight < 10(th) centile, (2) weight < 3(rd) centile, (3) z score difference from birth > 1 and, (4) z score difference from birth > 2; were compared for their predictive values and strength of association with adverse neurodevelopmental outcomes at 18-24 months. RESULTS: Postnatal growth failure defined as a decrease in z score of > 2 between birth and 36 weeks corrected gestational age had the best predictive values compared to other postnatal growth failure measures, however, it was significantly associated with psychomotor developmental (P=0.006) but not with mental developmental indices (P=0.379). CONCLUSION: Postnatal growth failure defined by z score change influenced psychomotor but not mental tasks in this cohort. This method of ascertainment could be useful to identify infants who might benefit from nutritional interventions.