The Prevalence of Small for Gestational Age and Extrauterine Growth Restriction among Extremely and Very Preterm Neonates, Using Different Growth Curves, and Its Association with Clinical and Nutritional Factors

Monitoring the growth of neonates in the Neonatal Intensive Care Unit (NICU) using growth charts constitutes an essential part of preterm infant care. Preterm infants are at increased risk for extrauterine growth restriction (EUGR) due to increased energy needs and clinical complications. This retrospective study compares the prevalence of small for gestational age (SGA) at birth and EUGR at discharge in extremely and very preterm neonates hospitalized in the NICU of a tertiary hospital in Greece, using different growth curves, and it examines the associated nutritional and clinical factors. Fenton2013 and INTERGROWTH-21st growth curves were used to calculate z-scores of birth weight (BW) and weight, length, and head circumference at discharge. The study includes 462 newborns with a mean BW of 1341.5 g and mean GA of 29.6 weeks. At birth, 6.3% of neonates were classified as SGA based on Fenton2013 curves compared to 9.3% with INTERGROWTH-21st growth curves. At discharge, 45.9% of neonates were characterized as having EUGR based on the Fenton2013 weight curves and 29.2% were characterized based οn INTERGROWTH-21st curves. Nutritional factors such as the day of initiation, attainment of full enteral feeding, and the duration of parenteral nutrition were associated with EUGR by both curves. The prevalence of SGA and EUGR neonates differs between the two growth references. This shows that further evaluation of these charts is needed to determine the most appropriate way to monitor infant growth.