The Impact of Estimated Energy and Protein Balances on Extrauterine Growth in Preterm Infants.

BACKGROUND: Nutritional support of preterm infants remains a field of debate in the literature and clinical practice varies significantly. Adequate nutrition should promote growth and aim for optimal later neurodevelopment. However, it is often impaired by prematurity-associated morbidity and the physiologic immaturity of preterm infants. This study assessed the impact of energy and macronutrient provision on growth velocity and outcome and explored differences attributed to the heterogeneity of the preterm population. METHODS: We retrospectively collected clinical and nutritional data from neonates hospitalized in two separate Neonatal Intensive Care Units (NICUs). Estimated energy and protein balance were calculated based on the ESPGHAN guidelines and their association with the growth outcome was explored. Growth assessment was based on somatometry Delta (Δ) z-scores at discharge. RESULTS: In total, 174 neonates were included in the study. By day 14, most preterm infants were exclusively enterally fed, whereas there were infants in the <28 and 28-31+6 subgroups fed exclusively parenterally. Energy balance was positive for all gestational age (GA) subgroups except for those born <28 weeks. Protein balance was consistently positive for extremely premature but negative for late preterms. Cumulative substrates provisions were strong predictors of a positive energy or protein balance in the <34 weeks GA preterms on days 14 (ROC analyses, p < 0.001) and 7 (p < 0.05). A higher GA (p = 0.013) and enteral nutrition (p = 0.005) were additional predictors of a positive energy balance. All GA subgroups had a negative Δ z-score of weight at discharge. In the <34 GA subcohorts, a positive protein balance on day 14 (p = 0.009) and a short time to regain birth weight (exp(B) 3.1 (p = 0.004)) were independently associated with a positive Δ z-score of weight at discharge. CONCLUSIONS: Early achievement of a positive energy and protein balance, based on the ESPGHAN guidelines, is crucial to ensure optimal postnatal growth and prevent extrauterine growth restriction, a relatively common occurrence in preterm infants.

Ultrasonographic spleen dimensions in preterm infants during the first 3 months of life.

OBJECTIVE: The purpose of this study was to ultrasonographically evaluate spleen dimensions in healthy prematurely born neonates and infants during the first 3 months of life. METHODS: Ninety-six neonates and infants aged from 2 to 90 days, with gestational ages from 25 to 35 weeks, were prospectively examined between 2001 and 2003. None had either infectious or other serious diseases or congenital disorders. The relationships between the ultrasonographically measured spleen size parameters and postmenstrual age, sex, gestational age, and somatometric parameters (height, weight, and body surface area) were studied with linear regression models with backward selection. Spleen dimension growth curves and upper/lower limits defined by the upper/lower 95% confidence interval were presented in graphs by height, weight, and body surface area. In addition, spleen length was compared with recently published data on term peers. RESULTS: All spleen dimensions were positively correlated with postmenstrual age and somatometric parameters. Sex did not influence the variability of spleen dimensions. Spleen length had lower values and a smaller rate of growth in preterm than term neonates and infants. CONCLUSIONS: We have provided ultrasonographic spleen volumetric values in preterm neonates and infants during the first 3 months of life, giving reference standards applicable for clinical practice or research purposes.