Neuropsychological Development and New Criteria for Extrauterine Growth Restriction in Very Low-Birth-Weight Children

Variability in Definitions and Criteria of Extrauterine Growth Restriction and Its Association with Neurodevelopmental Outcomes in Preterm Infants: A Narrative Review

Extrauterine growth restriction (EUGR) has been used in the literature and clinical practice to describe inadequate growth in preterm infants. Significant variability is seen in the criteria for EUGR, with no standard definition reached to date. Moreover, no consensus on the optimal timing for assessment or the ideal growth monitoring tool has been achieved, and an ongoing debate persists on the appropriate terminology to express poor postnatal growth. To ensure an adequate understanding of growth and early intervention in preterm infants at higher risk, it is critical to relate the diagnostic criteria of EUGR to the ability to predict adverse outcomes, such as neurodevelopmental outcomes. This narrative review was conducted to present evidence that evaluates neurodevelopmental outcomes in preterm infants with EUGR, comparing separately the different definitions of this concept by weight (cross-sectional, longitudinal and "true" EUGR). In this article, we highlight the challenges of comparing various published studies on the subject, even when subclassifying by the definition of EUGR, due to the significant variability on the criteria used for each definition and for the evaluation of neurodevelopmental outcomes in different papers. This heterogeneity compromises the obtention of a single firm conclusion on the relation between different definitions of EUGR and adverse neurodevelopmental outcomes.

Effect of SMOF lipid emulsion on physical growth and extrauterine growth retardation in very preterm infants: Insights from a multicenter retrospective cohort study

OBJECTIVE

The aim of this study was to investigate the effects of soybean, medium-chain triacylglycerols (MCTs), olive oil, and fish oil (SMOF) on short-term clinical outcomes, physical growth, and extrauterine growth retardation (EUGR) in very preterm infants.

METHODS

This was a multicenter retrospective cohort study of very preterm infants hospitalized in neonatal intensive care units at five tertiary hospitals in China between January 2021 and December 2021. According to the type of fat emulsion used in parenteral nutrition (PN), eligible very preterm infants were divided into the MCTs/long-chain triacylglycerol (MCT/LCT) group and SMOF group. Change in weight z-score (weight Δz) between measurements at birth and at 36 wk of postmenstrual age or at discharge, the incidence of EUGR, and short-term clinical outcomes between the two groups were compared and analyzed.

RESULTS

We enrolled 409 very preterm infants, including 205 in the MCT/LCT group and 204 in the SMOF group. Univariate analysis showed that infants in the SMOF group had significantly longer duration of invasive mechanical ventilation and PN, longer days to reach total enteral nutrition, and a higher proportion of maximum weight loss than those in MCT/LCT group (all P < 0.05). After adjusting for the confounding variables, multifactorial logistic regression analysis of short-term clinical outcomes showed that SMOF had protective effects on PN-associated cholestasis (odds ratio [OR], 0.470; 95% confidence interval [CI], 0.266-0.831) and metabolic bone disease of prematurity (OR, 0.263; 95% CI, 0.078-0.880). Additionally, SMOF was an independent risk factor for lower weight growth velocity (β = -0.733; 95% CI, -1.452 to -0.015) but had no effect on the incidence of EUGR (OR, 1.567; 95% CI, 0.912 to -2.693).

CONCLUSION

Compared with MCT/LCT, SMOF can reduce the risk for PN-associated cholestasis and metabolic bone disease of prematurity in very preterm infants and has a negative effect on growth velocity but has no effect on the incidence of EUGR.

Challenges in the growth and development of newborns with extra-uterine growth restriction

INTRODUCTION

Extra-uterine growth restriction (EUGR) is a condition caused by the failure of very preterm infants to reach their potential growth during the NICU hospital stay. Despite enormous improvements in nutritional support and strategies, the growth pattern of preterm infants is still far from the one expected.

AREAS COVERED

This review focuses on what EUGR is, highlighting controversial aspects of this topic. EUGR is still missing a univocal definition, and the international debate is also open on what is the best growth chart to use. Moreover, professionals in NICU may not be trained on how to perform anthropometric measurements, increasing the risk of over- or underestimation, especially for length assessment. EUGR has recently been described as one of the main comorbidities in NICU, influencing growth, metabolism, and neurodevelopment later in life.

EXPERT OPINION

There is still much to investigate about what the best growth pattern in the NICU should be. What is known so far is that the majority of preterm neonates develop EUGR, and this leads to several short- and long-term consequences. It is imperative that neonatologists and pediatric endocrinologists work together, to modulate growth in the NICU.