Expert recommendations for preterm neonates' growth goals: Considerations for clinicians

Neonatal nutrition experts traditionally recommend that preterm infants achieve postnatal growth approximating intrauterine fetal growth rates. Preterm infant growth has three phases: postnatal weight loss, approximately parallel growth, and catch-up growth. Growth approximately parallel to growth chart curves can be appropriate even when plotting below any given percentile. Growth patterns are influenced by genetic potential, health determinants, pre-birth environment (maternal morbidities), post-birth morbidity, nutrition and feeding ability. To achieve genetic potential, some infants need growth to catch-up and some catch-down. There is considerable overlap between the growth of healthy infants and those with growth faltering. Growth expectations must be individualized in order to account for normal physiological and genetic variations and to help identify modifiable factors. No specific percentile, z-score or change in z-scores should be set as universal growth goals; rather, individual variability should be expected. The expert groups did not favour the words "failure" and "restriction" to describe postnatal growth perhaps because these words are usually based on arbitrary percentile/z-score cut-offs using one-point-in-time measures and ignore that postnatal weight loss places infants lower on growth chart curves. The word "failure" is pejorative while "faltering" suggests a temporary problem.