Does faster weight trajectory lead to improved neurodevelopmental outcomes in ELBW infants with bronchopulmonary dysplasia?

OBJECTIVE: Examine the relationship between weight trajectory and 2-year neurodevelopmental outcomes for extremely low birthweight (ELBW) infants with BPD. STUDY DESIGN: Secondary analysis of infants born from 2010 to 2019. The predictor was BPD severity and the outcome was neurodevelopmental impairment, defined as any Bayley Scales of Infant Development (BSID) III score <70 at 24 months' corrected age. Repeated measures logistic regression was performed. RESULTS: In total, 5042 infants were included. Faster weight trajectory was significantly associated with a decreased probability of having at least one BSID III score <70 for infants with grade 1-2 BPD (p < 0.0001) and an increased probability of at least one BSID III score <70 for infants with grade 3 BPD (p < 0.009). There was no significant association between weight trajectory and BSID III score <70 for infants with grade 0 BPD. CONCLUSION: The association between postnatal weight trajectory and neurodevelopmental outcome in this study differs by BPD severity.

Infant body composition: A comprehensive overview of assessment techniques, nutrition factors, and health outcomes.

Body composition assessment is a valuable tool for clinical assessment and research that has implications for long-term health. Unlike traditional measurements such as anthropometrics or body mass index, body composition assessments provide more accurate measures of body fatness and lean mass. Moreover, depending on the technique, they can offer insight into regional body composition, bone mineral density, and brown adipose tissue. Various methods of body composition assessment exist, including air displacement plethysmography, dual-energy x-ray absorptiometry, bioelectrical impedance, magnetic resonance imaging, D3 creatine, ultrasound, and skinfold thickness, each with its own strengths and limitations. In infants, several feeding practices and nutrition factors are associated with body composition outcomes, such as breast milk vs formula feeding, protein intake, breast milk composition, and postdischarge formulas for preterm infants. Longitudinal studies suggest that body composition in infancy predicts later body composition, obesity, and other cardiometabolic outcomes in childhood, making it a useful early marker of cardiometabolic health in both term and preterm infants. Emerging evidence also suggests that body composition during infancy predicts neurodevelopmental outcomes, particularly in preterm infants at high risk of neurodevelopmental impairment. The purpose of this narrative review is to provide clinicians and researchers with a comprehensive overview of body composition assessment techniques, summarize the links between specific nutrition practices and body composition in infancy, and describe the neurodevelopmental and cardiometabolic outcomes associated with body composition patterns in term and preterm infants.

Dilemmas in establishing preterm enteral feeding: where do we start and how fast do we go?

Beginning and achieving full enteral nutrition is a key step in the care of preterm infants, particularly very low birth weight (VLBW) infants. As is true for many organ system-specific complications of prematurity, the gastrointestinal tract must complete in utero development ex utero while concurrently serving a physiologic role reserved for after completion of full term development. The preterm gut must assume the placental function of the interface between a source of energy, precursors for anabolism, and micronutrients, and the developing infant-through digestion and absorption of milk, instead of directly from the mother via the uteroplacental interface. The benefits of enteral nourishment in preterm infants are counterbalanced by gastrointestinal complications of prematurity: dysmotility leading to difficulty establishing and advancing feeds, and the risk of necrotizing enterocolitis (NEC). Concern for these complications can prolong the need for parenteral nutrition with an associated increase in risk for central line-associated bloodstream infection (CLABSI) and parenteral nutrition (PN)-associated cholestasis or liver disease (PNALD). Thus, a daily issue facing neonatologists caring for preterm infants is how to optimally begin, advance, and reach full enteral nutrition sufficient to satisfy the nutrient, energy, and fluid requirements of VLBW infants while minimizing risk. In this perspective, we provide an overview of the approaches and supporting data for starting and advancing enteral feeds in preterm infants, particularly very low birth weight infants, and we discuss the significant gaps in knowledge that accompany current approaches. This framework recognizes the dilemmas of preterm feeding initiation and advancement and identifies areas of opportunity for further investigation.

Racial differences in growth rates and body composition of infants born preterm.

OBJECTIVE: To evaluate racial disparities in weight gain velocity and body composition among preterm infants. STUDY DESIGN: This observational study analyzed race differences in fat-free mass (FFM), fat mass (FM), percent body fat (%BF), and weight gain at discharge of infants born at 25-32 weeks of gestation. RESULTS: No racial differences in FFM, FM and %BF measurements were found between black and white preterm infants after adjusting for birth weight, gestational age, and the presence/absence of breastfeeding (n = 143). Black infants born preterm had lower birthweights and higher weight gain from birth to discharge in unadjusted and adjusted models (13 ± 3 vs. 11 ± 3 g/kg/day; <0.001). CONCLUSION: Black infants had higher weight gain from birth to discharge, but comparable body composition measurements at discharge. More research is needed to understand contributing factors and long-term implications of this finding.

Body composition of extremely preterm infants fed protein-enriched, fortified milk: a randomized trial.

BACKGROUND: Critically ill extremely preterm infants fed human milk are often underrepresented in neonatal nutrition trials aimed to determine the effects of enteral protein supplementation on body composition outcomes. METHODS: Masked randomized trial in which 56 extremely preterm infants 25-28 weeks of gestation were randomized to receive either fortified milk enriched with a fixed amount of extensively hydrolyzed protein (high protein group) or fortified milk without additional protein (standard protein group). RESULTS: Baseline characteristics were similar between groups. In a longitudinal analysis, the mean percent body fat (%BF) at 30-32 weeks of postmenstrual age (PMA), 36 weeks PMA, and 3 months of corrected age (CA) did not differ between groups (17 ± 3 vs. 15 ± 4; p = 0.09). The high protein group had higher weight (-0.1 ± 1.2 vs. -0.8 ± 1.3; p = 0.03) and length (-0.8 ± 1.3 vs. -1.5 ± 1.3; p = 0.02) z scores from birth to 3 months CA. The high protein group also had higher fat-free mass (FFM) z scores at 36 weeks PMA (-0.9 ± 1.1 vs. -1.5 ± 1.1; p = 0.04). CONCLUSIONS: Increased enteral intake of protein increased FFM accretion, weight, and length in extremely preterm infants receiving protein-enriched, fortified human milk. IMPACT: Extremely preterm infants are at high risk of developing postnatal growth failure, particularly when they have low fat-free mass gains. Protein supplementation increases fat-free mass accretion in infants, but several neonatal nutrition trials aimed to determine the effects of enteral protein supplementation on body composition outcomes have systematically excluded critically ill extremely preterm infants fed human milk exclusively. In extremely preterm infants fed fortified human milk, higher enteral protein intake increases fat-free mass accretion and promotes growth without causing excessive body fat accretion.

Percent Body Fat Content Measured by Plethysmography in Infants Randomized to High- or Usual-Volume Feeding after Very Preterm Birth.

We measured percent body fat by air-displacement plethysmography in 86 infants born at <32 weeks of gestation randomized to receive either high-volume (180-200 mL/kg/day) or usual volume feeding (140-160 mL/kg/day). High-volume feeding increased percent body fat by ≤2% at 36 weeks of postmenstrual age (within a predefined range of equivalence). TRIAL REGISTRATION: ClincialTrials.gov: NCT02377050.

Serial assessment of fat and fat-free mass accretion in very preterm infants: a randomized trial.

BACKGROUND: Clinicians could modify dietary interventions during early infancy by monitoring fat and fat-free mass accretion in very preterm infants. METHODS: Preterm infants were randomly assigned to either having reports on infant body composition available to the clinicians caring for them (intervention group) or not having reports available (control group). All infants underwent serial assessments of body composition by air-displacement plethysmography before 32 weeks of postmenstrual age (PMA) and at 36 weeks PMA. The primary outcome was percent body fat (%BF) at 3 months of corrected age (CA). RESULTS: Fifty infants were randomized (median gestational age: 30 weeks; mean ± SD birth weight: 1387 ± 283 g). The mean %BF increased from 7 ± 4 before 32 weeks PMA to 20 ± 5 at 3 months CA. The differences in mean %BF between the intervention group and the control group were not statistically significant at 36 weeks PMA (14.5 vs. 13.6) or 3 months CA (20.8 vs. 19.4). Feeding practices and anthropometric measurements during hospitalization did not differ between groups. CONCLUSIONS: Serial assessments of body composition in both intervention and control groups showed consistent increments in %BF. However, providing this information to clinicians did not influence nutritional practices or growth. IMPACT: Serial assessments of body composition in preterm infants at 32 and 36 weeks postmenstrual age show consistent increments in % body fat up to 3 months of corrected age. However, providing this information to the clinician did not influence nutritional practices or growth.