Growth patterns and body composition in former extremely low birth weight (ELBW) neonates until adulthood: a systematic review

Abstract

Preterm infants are obviously born lighter and shorter, with smaller head circumferences than normal birth weight term born neonates. They also have a different body composition. Compromised growth is associated with adverse health outcomes. Both growth retardation and accelerated growth are suggested to cause metabolic, cardiovascular, and renal complications. Reviews regarding growth and body composition in preterm infants often do not differentiate between birth weight and gestational age. The purpose of this systematic review is to assemble growth data, specific in extremely low birth weight children. Different databases were searched for studies regarding growth and body composition in former extremely low birth weight infants until adulthood. We compared height, weight, head circumference, body mass index, fat mass, lean mass, fat distribution, and body water to matched normal birth weight controls and the World Health Organization growth charts. Studies consistently reported that former extremely low birth weight neonates experience a period of accelerated postnatal growth, but they achieve lower anthropometric parameters than normal birth weight children. There is no consensus about differences in body composition and how to measure this. Conclusion: Although extremely low birth weight infants exhibit a period of catch-up growth, their growth remains retarded later in life. Further research is needed to investigate body composition and the associated risk of cardiovascular diseases or metabolic syndrome. What is Known: • Extremely low birth weight infants have lower anthropometric parameters and a different body composition at birth and term-corrected age than normal birth weight infants. • Former extremely low birth weight infants also have a higher risk on adverse cardiovascular health outcomes in later life. What is New: • After hospital discharge, extremely low birth weight neonates remain smaller and probably also lighter, with smaller head circumferences at each corrected age throughout childhood and adolescence when compared to normal birth weight infants or the World Health Organization growth charts. It is not clear whether extremely low birth weight infants reach a lower or similar body mass index score as normal birth weight infants. • There is a lack of (long-term) information on body composition in extremely low birth weight infants.

Identification of Growth Patterns in Low Birth Weight Infants from Birth to 5 Years of Age: Nationwide Korean Cohort Study

“…Our findings are consistent with those of previous international studies, which reported that a lot of preterm infants born lighter and shorter than full-term infants remain growth-restricted beyond the catch-up period [14]. We found that some degree of catch-up growth did occur with time; however, the difference remained until 60 months of age compared to the infants with 2500-4500 g. As shown in Figure 1, the smaller birth-weight group showed lower catch-up growth even at 60 months.…”

Weight gain velocity and adequate amount of nutrition for infants with congenital diaphragmatic hernia

“…Catch-up growth during infancy can be directly related to improved neurodevelopment [4,5]. Evidence, therefore, has been accumulated in preterm infants [20]. Furthermore, nutrient deprivation during the neonatal period is seen not only in preterm infants, but also in term infants requiring surgery and/or intensive care.…”

Improving long-term health outcomes of preterm infants: how to implement the findings of nutritional intervention studies into daily clinical practice

“…The link between prematurity and metabolic syndrome may be partly explained by catch-up growth after EUGR [ 14 , 36 ]. Although those born with extremely low birth weight (i.e., < 1000 g) do experience accelerated postnatal growth, they still remain smaller and lighter throughout childhood than those term born with inconsistent findings with regard to body composition [ 37 ]. Nonetheless, catch-up growth accompanied by fat mass accretion exceeding linear growth predisposes to infant adiposity, and subsequent tracking of fat mass from infancy into childhood and adulthood predisposes to metabolic syndrome [ 38 ].…”