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

ABSTRACT

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.

KEYWORDS:

• Catch-up growth
• Extra-uterine growth restriction
• Growth
• metabolism
• neurodevelopment
• prematurity
• short stature
• very low birth weight

Article highlights

• There is still no univocal agreement on the best definition of extrauterine growth restriction.

• The literature reports both ‘static’ and ‘dynamic’ definitions, but long-term studies are needed to better understand what exactly should be considered as EUGR.

• Growth charts for preterm infants, especially for very preterm (VLBW and ELBW), have changed during the past 20 years from the common use of reference charts to the more recent use of standard charts. It is still a matter of debate what is the best chart to be used.

• In NICU, it is challenging to measure a preterm neonate. In fact, seeing the critical acute clinical conditions, anthropometric measurements are not a priority. Measurements are often not accurate, influencing the consequent growth curve of the baby.

• Independently of the best and most accurate definition, EUGR is nowadays considered a major risk factor for long term clinical outcomes of preterm infants, in particular growth, metabolism, and neurodevelopment.

• According to the international recommendations for growth hormone treatment, length and/or weight at birth but not at discharge is included in clinical criteria for growth hormone prescription. This indication excludes from the treatment of the patients who experience EUGR, if they do not develop growth hormone deficiency later in life.

• EUGR, for those who develop fetal growth restriction and are born at term small for gestational age, increases the risk of metabolic comorbidities later in life, such as hypertension, alteration of glucose metabolism, and dyslipidemia.

• Recent literature is focusing on the effects of EUGR on neurodevelopment. Patients experiencing EUGR are at higher risk for impairments of motor and cognitive performances.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.