Determination of nutritional requirements in preterm infants, with special reference to 'catch-up' growth

Early Nutrition during Hospitalization in Relation to Bone Health in Preterm Infants at Term Age and Six Months Corrected Age

Aim: to evaluate the potential association of macronutrient intake in the first postnatal weeks on bone mineral content (BMC) and bone mineral density (BMD) in extremely and very preterm infants. Methods: fifty-eight extremely and very preterm infants were included. Daily macronutrient intake was calculated in g kg⁻¹ day⁻¹ from birth up to 36 weeks postmenstrual age. A dual-energy X-ray absorptiometry whole body scan was used to assess BMC and BMD in preterm infants at term corrected age (TCA) and six months corrected age (CA). Results: fat intake (g kg⁻¹ day⁻¹) in the first four postnatal weeks was positively associated with BMC and BMD at TCA. At six months CA, protein and fat intake (g kg⁻¹ day⁻¹) in the first weeks of life were both individual predictors for BMD. Fat intake (g kg⁻¹ day⁻¹) in the first four postnatal weeks was significantly associated with BMC at six months CA. Conclusion: the association of macronutrient intake in the first postnatal weeks on BMC or BMD, at TCA and six months CA, suggest that early nutritional intervention immediately after birth and during early infancy is important for bone health in the first months of life.

Comparison of Oxidative Status of Human Milk, Human Milk Fortifiers and Preterm Infant Formulas

Preterm and low birth weight infants require specific nutrition to overcome the accumulated growth deficit, and to prevent morbidities related to postnatal growth failure. In order to guarantee an adequate nutrient-intake, mother’s own milk, when available, or donor human milk, are usually fortified with additional nutrients, in particular proteins. Fortification with processed ingredients may result in additional intake in oxidative compounds, deriving from extensive heat treatments, that are applied during processing. The aim of the present work was to compare the in vitro antioxidant activity and oxidative compound content conveyed by different preterm infant foods and fortifiers, namely raw and pasteurized human milk, two different preterm infant formulas, three bovine milk-based fortifiers and two experimental donkey milk-based fortifiers. Univariate and multivariate statistical analyses revealed significant differences between the different products. The use of human milk minimizes the intake of dietary oxidative compound in comparison to infant formulas, irrespective of pasteurization or fortification, especially as far as malondialdehyde content is concerned. The addition of fortifiers to human milk increases its antioxidant capacity, and the choice of the protein source (hydrolysed vs. whole proteins) differently impacted the resulting total antioxidant capacity of the diet.

Post-discharge body weight and neurodevelopmental outcomes among very low birth weight infants in Taiwan: A nationwide cohort study

Background

Premature infants are at high risk for developmental delay and cognitive dysfunction. Besides medical conditions, growth restriction is regarded as an important risk factor for cognitive and neurodevelopmental dysfunction throughout childhood and adolescence and even into adulthood. In this study, we analyzed the relationship between post-discharge body weight and psychomotor development using a nationwide dataset.

Materials and methods

This was a nationwide cohort study conducted in Taiwan. Total of 1791 premature infants born between 2007 and 2011 with a birth weight of less than 1500 g were enrolled into this multi-center study. The data were obtained from the Taiwan Premature Infant Developmental Collaborative Study Group. The growth and neurodevelopmental evaluations were performed at corrected ages of 6, 12 and 24 months. Post-discharge failure to thrive was defined as a body weight below the 3rd percentile of the standard growth curve for Taiwanese children by the corrected age.

Results

The prevalence of failure to thrive was 15.8%, 16.9%, and 12.0% at corrected ages of 6, 12, and 24 months, respectively. At corrected ages of 24 months, 12.9% had low Mental Developmental Index (MDI) scores (MDI<70), 17.8% had low Psychomotor Developmental Index (PDI) scores (PDI<70), 12.7% had cerebral palsy, and 29.5% had neurodevelopmental impairment. Post-discharge failure to thrive was significantly associated with poor neurodevelopmental outcomes. After controlling for potential confounding factors (small for gestational age, extra-uterine growth retardation at discharge, cerebral palsy, gender, mild intraventricular hemorrhage, persistent pulmonary hypertension of newborn, respiratory distress syndrome, chronic lung disease, hemodynamic significant patent ductus arteriosus, necrotizing enterocolitis, surfactant use and indomethacin use), post-discharge failure to thrive remained a risk factor.

Conclusion

This observational study observed the association between lower body weight at corrected age of 6, 12, and 24 months and poor neurodevelopmental outcomes among VLBW premature infants. There are many adverse factors which can influence the neurodevelopment in NICU care. More studies are needed to elucidate the causal relationship.

Nutritional support for low birth weight infants: insights from animal studies

Infants born with low birth weights (<2500 g, LBW), accounting for about 15 % of newborns, have a high risk for postnatal growth failure and developing the metabolic syndromes such as type 2 diabetes, CVD and obesity later in life. Improper nutrition provision during critical stages, such as undernutrition during the fetal period or overnutrition during the neonatal period, has been an important mediator of these metabolic diseases. Considering the specific physiological status of LBW infants, nutritional intervention and optimisation during early life merit further attention. In this review, the physiological and metabolic defects of LBW infants were summarised from a nutritional perspective. Available strategies for nutritional interventions and optimisation of LBW infants, including patterns of nutrition supply, macronutrient proportion, supplementation of amino acids and their derivatives, fatty acids, nucleotides, vitamins, minerals as well as hormone and microbiota manipulators, were reviewed with an aim to provide new insights into the advancements of formulas and human-milk fortifiers.

Early Elevation in Interleukin-6 is Associated with Reduced Growth in Extremely Low Birth Weight Infants

Objective To determine whether reduced growth velocity (GV) in extremely low birth weight infants is preceded by elevated inflammatory cytokines. Study Design GV was determined at 36 weeks' postmenstrual age (PMA) in 768 infants 401 to 1,000 g birth weight (BW). Association between blood cytokines measured through day of life 21 and GV was explored using linear regression models that adjusted for late-onset sepsis (LOS), BW, small for gestational age (SGA), gender, race, energy intake, and center. Results Serum interleukin-6 (IL-6) was increased at days 14 and 21 in LOS infants. LOS was associated with reduced energy intake and GV for weight (weight-GV) at 36 weeks' PMA. Linear regression analysis controlling for LOS and energy intake showed significant relationships between increased IL-6 at days 14 and 21 with reduced weight-GV at 36 weeks' PMA (p < 0.0001). The relationship between day 21 IL-6 and weight-GV was not associated with LOS (p = 0.12) when controlling for BW and energy intake. Both BW (p = 0.02) and energy intake (p = 0.003) influenced the relationship between day 14 IL-6 and weight-GV. Conclusion IL-6 elevation during the first month of life is associated with lower weight-GV at 36 weeks' PMA and may have a direct effect upon energy balance and postnatal growth.

Advances in the nutrition of preterm infants

The greatly improved survival rate of infants born both preterm and low birth weight (LBW) has led to the subsequent growth and development of these infants becoming an important focus for research. Preterm infants begin life with, or acquire as a result of their prematurity, greater morbidity than term born babies, growth deficits, an increased risk of developmental delay and an increased risk of later adult diseases compared with appropriate for gestational age (AGA) term born babies.

Research in recent decades has confirmed that there are marked differences in the nutritional requirements of preterm LBW infants compared with their AGA term born counterparts, both in the neonatal period and probably for all of infancy. In addition to the increased requirement for energy and protein, preterm LBW infants demonstrate a greatly increased requirement for some of the mineral elements, particularly iron, zinc and calcium, when compared with the needs of term AGA infants. In the UK, feeding practices for preterm infants in neonatal units and throughout infancy after hospital discharge are variable and many questions remain as to the optimal nutritional regimen for preterm LBW infants (and for subgroups of these infants) at different stages of infancy. There is some concern that the 2002 World Health Organization recommendations on infant feeding may be applied to all infants, including preterm infants, without consideration of their special nutritional needs, which may further compromise their growth and development.

A brief résumé of the work of prominent researchers in the field of preterm infant nutrition in the UK, notably Lucas, Cooke and Fewtrell, is included in the review, together with information from papers published by the authors of the review. The review concludes with a summary of the generally accepted recommendations on feeding preterm LBW infants after hospital discharge and information on some practical help available to the parents of these children and to health workers in the field.

Effect of Intra- and Extrauterine Growth on Long-Term Neurologic Outcomes of Very Preterm Infants

OBJECTIVE

To determine whether extrauterine growth is associated with neurologic outcomes and if this association varies by prenatal growth profile.

STUDY DESIGN

For 1493 preterms from the EPIPAGE (Étude Épidémiologique sur les Petits Âges Gestationnels [Epidemiological Study on Small Gestational Ages]) cohort, appropriate for gestational-age (AGA) was defined by birth weight >-2 SD and small for gestational-age (SGA) by birth weight ≤-2 SD. Extra-uterine growth was defined by weight gain or loss between birth and 6 months by z-score change. Growth following-the-curve (FTC) was defined as weight change -1 to +1 SD, catch-down-growth (CD) as weight loss ≥1 SD, and catch-up-growth (CU) as weight gain ≥1 SD. At 5 years, a complete medical examination (n = 1305) and cognitive evaluation with the Kauffman Assessment Battery for Children (n = 1130) were performed. Behavioral difficulties at 5 years and school performance at 8 years were assessed (n = 1095).

RESULTS

Overall, 42.5% of preterms were AGA-FTC, 20.2% AGA-CD, 17.1% AGA-CU, 5.6% SGA-FTC, and 14.5% SGA-CU. Outcomes did not differ between CU and FTC preterm AGA infants. Risk of cerebral palsy was greater for AGA-CD compared with AGA-FTC (aOR 2.26 [95% CI 1.37-3.72]). As compared with children with SGA-CU, SGA-FTC children showed no significant increased risk of cognitive deficiency (aOR 1.41[0.94-2.12]) or school difficulties (aOR 1.60 [0.84-3.03]). Compared with AGA-FTC, SGA showed increased risk of cognitive deficiency (SGA-FTC aOR 2.19 [1.25-3.84]) and inattention-hyperactivity (SGA-CU aOR 1.65 [1.05-2.60]).

CONCLUSION

Deficient postnatal growth was associated with poor neurologic outcome for AGA and SGA preterm infants. CU growth does not add additional benefits. Regardless of type of postnatal growth, SGA infants showed behavioral problems and cognitive deficiency.

A new formula for premature infants: effects on growth and nutritional status

OBJECTIVE

Nutritional management influences immediate survival as well as subsequent growth and development of low birth weight and very low birth weight infants. Preterm infant formula (PTF) is used when there is an inadequate supply of mother's milk or when the mother is unable to breastfeed and donor breast milk is unavailable. The purpose of this prospective multicenter study was to evaluate short-term effects on nutritional status (auxological and biochemical parameters) in a population of premature infants who received a preterm infant formula.

METHODS

Ninety-seven preterm infants with a birth weight between 500 g and 2000 g and a gestational age of 25-34 weeks postmenstrual age were randomly assigned to received a new preterm infant formula (Nutribèn Pre), and their nutritional status were compared to 75 fortified human milk (FHM) fed infants.

RESULTS

No significant differences were observed between FHM and Nutribèn Pre fed infants in terms of growth, feeding tolerance and biochemical profiles.

CONCLUSION

Nutribèn Pre is a valid, effective and safe alternative for the nutrition of preterm infants.

Prevention of postnatal growth restriction by the implementation of an evidence-based premature infant feeding bundle

OBJECTIVE

To develop an evidence-based feeding bundle to safely decrease the rate of PNGR in VLBW infants.

STUDY DESIGN

The bundle was developed and implemented in January 2010, followed by 3 years of monitoring bundle compliance and infant outcomes (days to first feed (FD), days to reach full feeds (FF), and birth-discharge growth trajectories (delta z-score)).

RESULTS

Data were collected on 482 infants (119 pre-bundle). PNGR decreased from 35% to 19% (P<0.01) and weight delta z-score improved from -0.82 to -0.45 (P<0.001). Percentage of infants with head circumference (HC) below 10th percentile at discharge decreased from 21% to 9% (P<0.01) and HC delta z-score improved from -0.65 to -0.17 (P<0.001). FD and FF also decreased significantly. Rates of necrotizing enterocolitis, peak alkaline phosphatase and peak direct bilirubin levels all trended downward.

CONCLUSIONS

An evidence-based, standardized feeding bundle was safe and effective in reducing the rate of PNGR and in improving head growth in VLBW infants.

Optimizing nutrition in preterm infants

Extrauterine growth restriction is common in very preterm infants. The incidence in very-low-birth-weight infants ranges between 43% and 97% in various centers, with a wide variability due to the use of different reference growth charts and nonstandard nutritional strategies. Extrauterine growth restriction is associated with an increased risk of poor neurodevelopmental outcome. Inadequate postnatal nutrition is an important factor contributing to growth failure, as most very preterm infants experience major protein and energy deficits during neonatal intensive care unit hospitalization. First-week protein and energy intake are associated with 18-month developmental outcomes in very preterm infants. Early aggressive nutrition, including parenteral and enteral, is well tolerated in the very preterm infant and is effective in improving growth. Continued provision of appropriate nutrition (fortified human milk or premature formula) is important throughout the growing care during the hospitalization. After discharge, exclusively breast-fed infants require additional supplementation. If formula-fed, nutrient-enriched postdischarge formula should be continued for approximately 9 months corrected age. Supplementation of the preterm formulas with protein would increase the protein/energy ratio (3 g/100 kcal), leading to increased lean mass with relatively decreased fat deposition. Further research is required to optimize the nutritional needs of preterm infants and to evaluate the effects of nutritional interventions on long-term growth, neurodevelopment, and other health outcomes.

Creamatocrit analysis of human milk overestimates fat and energy content when compared to a human milk analyzer using mid-infrared spectroscopy

BACKGROUND AND OBJECTIVE

Human milk (HM) is the preferred feeding for human infants but may be inadequate to support the rapid growth of the very-low-birth-weight infant. The creamatocrit (CMCT) has been widely used to guide health care professionals as they analyze HM fortification; however, the CMCT method is based on an equation using assumptions for protein and carbohydrate with fat as the only measured variable. The aim of the present study was to test the hypothesis that a human milk analyzer (HMA) would provide more accurate data for fat and energy content than analysis by CMCT.

METHODS

Fifty-one well-mixed samples of previously frozen expressed HM were obtained after thawing. Previously assayed "control" milk samples were thawed and also run with unknowns. All milk samples were prewarmed at 40°C and then analyzed by both CMCT and HMA. CMCT fat results were substituted in the CMCT equation to reach a value for energy (kcal/oz). Fat results from HMA were entered into a computer model to reach a value for energy (kcal/oz). Fat and energy results were compared by paired t test with statistical significance set at P < 0.05. An additional 10 samples were analyzed locally by both methods and then sent to a certified laboratory for quantitative analysis. Results for fat and energy were analyzed by 1-way analysis of variance with statistical significance set at P < 0.05.

RESULTS

Mean fat content by CMCT (5.8 ± 1.9 g/dL) was significantly higher than by HMA (3.2 ± 1.1 g/dL, P < 0.001). Mean energy by CMCT (21.8 ± 3.4 kcal/oz) was also significantly higher than by HMA (17.1 ± 2.9, P < 0.001). Comparison of biochemical analysis with HMA of the subset of milk samples showed no statistical difference for fat and energy, whereas CMCT was significantly higher than for both fat (P < 0.001) and energy (P = 0.002).

CONCLUSIONS

The CMCT method appears to overestimate fat and energy content of HM samples when compared with HMA and biochemical methods.

The effects of varying protein and energy intakes on the growth and body composition of very low birth weight infants

Objective

To determine the effects of high dietary protein and energy intake on the growth and body composition of very low birth weight (VLBW) infants.

Study design

Thirty-eight VLBW infants whose weights were appropriate for their gestational ages were assessed for when they could tolerate oral intake for all their nutritional needs. Thirty-two infants were included in a longitudinal, randomized clinical trial over an approximate 28-day period. One control diet (standard preterm formula, group A, n = 8, 3.7 g/kg/d of protein and 129 kcal/kg/d) and two high-energy and high-protein diets (group B, n = 12, 4.2 g/kg/d and 150 kcal/kg/d; group C, n = 12, 4.7 g/kg/d and 150 kcal/kg/d) were compared. Differences among groups in anthropometry and body composition (measured with bioelectrical impedance analysis) were determined. An enriched breast milk group (n = 6) served as a descriptive reference group.

Results

Groups B and C displayed greater weight gains and higher increases in fat-free mass than group A.

Conclusion

An intake of 150 kcal/kg/d of energy and 4.2 g/kg/d of protein increases fat-free mass accretion in VLBW infants.

Nutrient enrichment of mother's milk and growth of very preterm infants after hospital discharge

OBJECTIVE

To determine if the addition of a multinutrient human milk fortifier to mother's milk while breastfeeding very preterm infants after hospital discharge is possible and whether it influences first-year growth.

METHODS

Of a cohort of 320 infants (gestational age: 24-32 weeks; birth weight: 535-2255 g), breastfed infants (65% [n = 207]) were randomly assigned shortly before hospital discharge to receive either unfortified (n = 102, group A) or fortified (n = 105, group B) mother's milk until 4 months' corrected age (CA). The remaining infants were bottle-fed with a preterm formula (group C). Follow-up was performed at term and at 2, 4, 6, and 12 months' CA.

RESULTS

Mean duration of breastfeeding after term was not significantly different between groups A and B (11.8 and 10.6 weeks, respectively). Weight, length, and head circumference were not significantly different between groups A and B at 12 months' CA. Compared with groups A and B, infants in group C had a higher increase in weight z score until term and in length z score until 6 months' CA. At 12 months' CA, boys in group C were significantly longer and heavier compared with those in groups A and B, whereas girls in group C were longer and heavier compared with those in group A only. A higher protein intake was related to a higher serum urea nitrogen level and growth.

CONCLUSIONS

Fortification of mother's milk after hospital discharge while breastfeeding very preterm infants was possible without influencing breastfeeding duration but did not significantly influence growth parameters at 1 year of age compared with unfortified mother's milk.

Eating problems at age 6 years in a whole population sample of extremely preterm children

AIM

The aim of this study was to investigate the prevalence of eating problems and their association with neurological and behavioural disabilities and growth among children born extremely preterm (EPC) at age 6 years.

METHOD

A standard questionnaire about eating was completed by parents of 223 children (125 males [56.1%], 98 females [43.9%]) aged 6 years who were born at 25 weeks' gestation or earlier (mean 24.5 wks, SD 0.7 wks; mean birthweight 749.1 g, SD 116.8 g), and parents of 148 classmates born at term (66 males [44.6%], 82 females [55.4%]). All children underwent neurological, cognitive, and anthropometric assessment, and parents and teachers completed a behaviour scale.

RESULTS

Eating problems were more common among the EPC than the comparison group (odds ratio [OR] 3.6, 95% confidence interval [CI] 2.1-6.3), including oral motor (OR 5.2, 95% CI 2.8-9.9), hypersensitivity (OR 3.0, 95% CI 1.6-5.6), and behavioural (OR 3.8, 95% CI 1.9-7.6) problems. Group differences were reduced after adjustment for cognitive impairment, neuromotor disability, and other behaviour problems. EPC with eating problems were shorter, lighter, and had lower mid-arm circumference and lower body mass index (BMI) even after adjusting for disabilities, gestational age, birthweight, and feeding problems at 30 months.

INTERPRETATION

Eating problems are still frequent in EPC at school age. They are only partly related to other disabilities but make an additional contribution to continued growth failure and may require early recognition and intervention.

Early amino-acid administration improves preterm infant weight

OBJECTIVE

Premature infants, especially those born less than 1500 g, often exhibit slow overall growth after birth and lack of early nutritional support may be an important element. We tested the hypothesis that early administration of amino acids (within the first few hours of life) to infants born at less than 1500 g would be associated with fewer infants that were less than the 10th percentile at 36 weeks post-conceptual age than infants that received amino acids after the first 24 h of life.

STUDY DESIGN

A prospective intervention of early amino-acid (EAA) supplementation, began before 24 h of life, in preterm infants, <1500 g, was compared to a retrospective cohort of preterm infants receiving late amino-acid (LAA) supplementation, began after 24 h of life. The primary outcome variable was the proportion of infants at less than the 10th percentile at 36 weeks post-conceptual age.

RESULT

Fewer infants fell below the 10th percentile (P<0.001) in the EAA group. Furthermore, infants in the EAA groups had significantly greater weight gains than did the LAA group (P<0.003) after adjusting for gestational age and time from birth to discharge. In addition, shorter duration of parenteral nutrition was associated with EAA supplementation (P<0.001).

CONCLUSION

A prospective strategy of EAA in preterm infants <1500 g was associated with an improved weight gain, suggesting that nutrition that included amino acids may be critical during the first 24 h of life.

Nutrição parenteral no recém-nascido pré-termo: proposta de protocolo prático

OBJETIVO: Revisar a literatura e os conceitos relacionados à terapia nutricional parenteral de recém-nascidos pré-termo e propor fluxograma prático de indicação, progressão dos parâmetros e monitoramento para utilização em unidades neonatais. FONTES DE DADOS: Artigos publicados em inglês e português nas bases de dados Medline, Embase, Lilacs e SciELO nos últimos dez anos, além de referências clássicas e consensos internacionais. As palavras-chave utilizadas como fonte de busca foram recém-nascido pré-termo, nutrição parenteral, terapia nutricional e emulsões lipídicas. SÍNTESE DOS DADOS: A nutrição parenteral é procedimento essencial no tratamento intra-hospitalar do recém-nascido pré-termo. Além dos avanços no conhecimento e progressos na legislação, vários fatores contribuíram para reduzir a morbimortalidade desses recém-nascidos e elevar a segurança na utilização da nutrição parenteral, tais como qualidade dos cateteres empregados, treinamento e capacitação adequada dos profissionais envolvidos, existência de equipes multiprofissionais e o desenvolvimento de novos insumos. CONCLUSÕES: Esse protocolo prático sobre nutrição parenteral para recém-nascidos prematuros foi desenvolvido com base em recomendações internacionais de sociedades científicas e na análise crítica de estudos científicos.

Improved growth and decreased morbidities in <1000 g neonates after early management changes

OBJECTIVE

To test the hypothesis that three changes in the early management of extremely low birth weight (ELBW) neonates would decrease the incidence of extra-uterine growth restriction (EUGR) by 25%. The three early management practice changes (EMPC) included surfactant at delivery followed by immediate extubation to nasal continuous positive airway pressure (CPAP), decreased oxygen exposure and early parenteral amino acids.

STUDY DESIGN

Historical cohort study of preterm infants<or=1000 g birth weight (BW) born at the University of Texas Medical Branch between January 2001 and June 2002 (pre-EMPC, before changes, n=87) and July 2004 to December 2005 (post-EMPC, after changes, n=76). Outcomes measured included feeding and growth parameters, morbidities and interventions. Statistical analysis included chi2-analysis, Student's t-test, and analysis of variance.

RESULT

Infants in the post-EMPC cohort regained BW more quickly, maintained appropriate size for weight at 36 weeks and had less morbidity associated with poor long-term outcome. Predictors of EUGR included BW<750 g and surgical necrotizing enterocolitis.

CONCLUSION

The introduction of surfactant at delivery followed by immediate extubation to CPAP, decreased oxygen exposure and early parenteral amino acids in ELBW infants is possible, safe and associated with improvements in growth and morbidity.

Feeding outcomes of extremely premature infants after neonatal care

Feeding is a primary concern for families of extremely preterm (EP) infants following discharge from neonatal care. An increasing number of EP children are being referred for treatment of feeding problems, including eating only a few types of food or very small portions, difficulty transitioning to textured foods, and refusing food. These issues have the potential for significant consequences for the children's growth and development as well as their family's well-being. An understanding of the kinds of feeding problems faced by families of EP infants can help nurses guide families to be ready for and respond to these issues. In this article, the evidence for and the nature of feeding problems in EP children after discharge from neonatal care are examined.

Protein metabolism in preterm infants with particular reference to intrauterine growth restriction

There is growing evidence that neonatal and long-term morbidity in preterm infants, particularly those born before 32 weeks' gestation, can be modified by attained growth rate in the neonatal period. Guidelines for optimal growth and the nutritional intakes, particular of protein, required to achieve this are not well defined. Due to delays in postnatal feeding and a lack of energy stores developed in the last trimester of pregnancy, preterm infants often suffer early postnatal catabolism until feeding is established. There are indications that infants born with intrauterine growth restriction have perturbations in protein metabolism. Therefore, they may have different protein requirements than appropriate for gestational age infants. This review summarises what is known about protein requirements and metabolism in the fetus and preterm infant, with particular emphasis on the distinct requirements of the growth-restricted infant.

Crescimento de prematuros de extremo baixo peso nos primeiros dois anos de vida

OBJETIVO: Analisar o padrão de crescimento de prematuros de extremo baixo peso (EBP) até 24 meses de idade corrigida, a influência da displasia broncopulmonar (DBP) e os fatores de risco para falha de crescimento. MÉTODOS: Coorte de prematuros <1.000g de gestação única, nascidos e acompanhados em um centro terciário. O crescimento foi avaliado por meio de escores-z para peso, comprimento e perímetro cefálico ao nascimento, com 40 semanas, aos 3, 6, 12, 18 e 24 meses de idade corrigida. Dentre 81 sobreviventes, 70 foram estudados e estratificados em dois grupos: DBP (n=41) e sem DBP (n=29). Foi realizada análise bivariada com teste t ou Mann-Whitney, qui-quadrado ou Exato de Fisher, e análise multivariada com regressão logística. RESULTADOS: Em ambos os grupos, o escore-z de peso diminuiu significantemente entre o nascimento e 40 semanas. Houve um pico de incremento nos escores-z de peso, comprimento e perímetro cefálico entre 40 semanas e três meses. No grupo sem DBP, os escores-z atingiram a faixa normal a partir dos seis meses e assim permaneceram até 24 meses de idade corrigida. Crianças com DBP tiveram menores escores-z de peso e perímetro cefálico no primeiro ano, mas equipararam-se às sem DBP no segundo ano de vida. A regressão logística mostrou que catch-down no escore-z de peso com 40 semanas foi fator de risco para falha de crescimento. CONCLUSÕES: Prematuros EBP apresentam catch-up precoce do crescimento nos primeiros dois anos. Crianças com DBP têm pior crescimento ponderal. A restrição do crescimento pós-natal prediz a falha de crescimento nos primeiros anos.

Enteral intake for very low birth weight infants: what should the composition be?

Providing optimal nutrition to satisfy the growth needs of very low birth weight infants is critical. The available preterm formulas and fortified human milk diets provide protein intakes of approximately 3.5 to 3.6 g/kg/d when volumes sufficient to provide 120 kcal/kg/d are fed to these infants. These intakes support growth and protein accretion at about or slightly greater than intrauterine rate and lead to relatively increased fat deposition. However, most very low birth infants fed these diets remain below the 10th percentile of the intrauterine growth standards at discharge. There is clear evidence that, with respect to growth, very low birth infants are likely to benefit from a higher protein intake; however, there is no clear evidence that energy intakes greater than 120 kcal/kg/d are needed. Although the upper limit of protein intake and the ideal protein:energy ratio remain controversial, there is enough evidence to support the beneficial and safe use of formulas providing protein:energy ratio of 3.2 to 3.3 g/100 kcal.

Biochemical homeostasis and body growth are reliable end points in clinical nutrition trials

Studies of biochemical homeostasis and/or body growth have been included as outcome variables in most nutrition trials in paediatric patients. Moreover, these outcome variables have provided important insights into the nutrient requirements of infants and children, and continue to do so. Examples of the value of such studies in improving parenteral nutrition, in defining essential fatty acid metabolism and requirements of infants and in defining the protein and energy needs of low-birth-weight infants are discussed. Data from such studies have helped to define the mechanism of metabolic acidosis and hyperammonaemia associated with the use of early crystalline amino acid mixture and, hence, how to prevent these disorders. Such studies have allowed the development of parenteral amino acid mixtures that circumvent grossly abnormal plasma concentrations of most amino acids and appear to be utilized more efficiently. These studies have also helped define micronutrient requirements, including requirements for several such nutrients that had not been previously recognized as essential (e.g. Cr, Se, Mo, α-linolenic acid). Studies of body growth have been particularly valuable in defining the nutritional requirements of low-birth-weight infants. Finally, studies of metabolic homeostasis coupled with more sophisticated metabolic studies have provided considerable insight into the metabolism of the essential fatty acids, linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3). Although such studies have not defined the amount of the longer-chain PUFA synthesized from each of these essential fatty acids, i.e. arachidonic acid (20:4n-6) and DHA (22:6n-3), they have shown that the rates of conversion are extremely variable from infant to infant, suggesting a possible explanation of why some studies show developmental advantages from intake of these fatty acids while others do not.

Posthospital discharge feeding for preterm infants: effects of standard compared with enriched milk formula on growth, bone mass, and body composition

BACKGROUND

Despite the theoretical benefits of nutrient-enriched formula given to preterm infants after hospital discharge, its role in reversing growth deficits after hospital discharge remains poorly defined.

OBJECTIVE

The aim was to determine the effect of different formulas on the growth, bone mass, and body composition of preterm infants after hospital discharge.

DESIGN

This was a randomized, double blind comparison of a nutrient-enriched formula (EF) and a formula for term infants (TF) given for 1 y after hospital discharge. Compared with the TF, the EF had a higher energy density and higher contents of protein, calcium, and phosphorus (by 10%, 21%, 44%, and 11%, respectively) and higher contents of almost all other nutrients (by >or=10%).

RESULTS

Birth weights of the infants were 630-1620 g (median: 1250 g) and gestational ages were 24-34 wk (median: 29 wk). TF resulted in significantly greater weight, length, head circumference measurements, and their respective z scores on the basis of age- and sex-specific norms. At the end of the study, the mean z scores for the corrected age of infants in the TF group were -0.37 for weight, 0.001 for length, and 0.50 for head circumference. The TF group also had significantly greater dual-energy X-ray absorptiometry measured bone and lean and fat mass than did the EF group (P < 0.05 for all comparisons).

CONCLUSIONS

The use of EF for preterm infants after hospital discharge shows no advantage over TF in growth, bone mineralization, and body composition. More studies are needed to determine the optimal postdischarge nutrition support for preterm infants.

Audit of feeding practices in babies<1200 g or 30 weeks gestation during the first month of life

AIM

In 2002, the composition of the breast milk fortifier used in our hospital changed, giving increased protein and energy. We therefore decided to prospectively audit nutritional management in our unit and to compare nutritional intake and growth in our babies with published data.

METHODS

Data were prospectively collected over a 3-month period on infants<1200 g or 30 weeks gestation. Prescribed and delivered volumes of all parenteral and enteral fluids were recorded. Babies were weighed as per unit protocol.

RESULTS

Thirty-four infants met the audit criteria. Data are median (range). After the first week of life, energy and protein intakes were 147 (78-174) kcal/kg/day and 3.9 (2.1-4.8) g/kg/day respectively. Daily weight gain was 17 (-3.2-35.4) g/kg and was significantly associated with both energy and protein intakes (P<0.001). However, standard deviation scores for weight fell from 0.15 (-1.9-2.0) at birth to -1.0 (-2.9-0.8) by 36 weeks corrected age. Time to commencing enteral feeds was 1 (1-3) day and to full enteral feeds was 8 (5-28) days. One infant was diagnosed with necrotising enterocolitis and eight with chronic lung disease. Mean protein intake was significantly lower in babies with chronic lung disease (P=0.005).

CONCLUSION

Overall, nutritional intakes and weight gain in this cohort of babies lie within the recommended ranges, although protein intakes in the smallest babies are at the lower end of the range. Enteral feeds are introduced early and advanced rapidly, but we have a low incidence of necrotising enterocolitis. However, babies still fell across weight centiles, suggesting that actual intakes for these tiny babies may be inadequate.

Postdischarge nutritional therapy

Nutrient-enriched diets for preterm infants after hospital discharge (preterm formula or postdischarge formula (PDF)) results in improved growth and these differences appear to persist beyond the period of nutrient intervention. The PDF diet effect is greatest in males, possibly reflecting their higher growth rates. The critical growth epoch appears to be the first 2 months post-term, suggesting a finite period and therefore opportunity for enhanced growth. Whether the observed growth effects persist further or have consequences for other aspects of health or development requires further investigation.

Extremely low birthweight infants: issues related to growth

While survival rates are increasing in the extremely low birthweight (ELBW) group of preterm infants, the most common morbidity among these infants is inadequate growth. By the time of discharge from the neonatal intensive care unit, many ELBW infants develop extrauterine growth restriction. Several issues related to improving the growth of ELBW infants, including defining adequate growth and developing evidence-based nutritional strategies, are discussed in this article. Suggestions for future research are also presented.

Nutrient-enriched Diet in the Early Neonatal Period Influences the 3-year-old Height in Very Low Birth Weight Infants

Nutrient-enriched milk has been advocated to enhance premature infants’growth and early nutritional intervention is effective for growth failure in very low birth weight infants (VLBWI). We studied the 3-yr-old physical growth of VLBWI who received nutrient enriched diets in the early neonatal period. VLBWI, who were born in 1996, received nutrient enriched milk around 1 mo of age. By contrast, in VLBWI born in 1998, nutrient enriched milk was started at 1–2 wk after birth. The daily calorie intake of VLBWI in 1998 had a tendency to be high compared to that of VLBWI in 1996. Height and body weight SD of 3-yr-old children who were born in 1998 tended to be greater than those of children who were born in 1996 (mean ± SD, –0.27 ± 0.54 vs. –1.01 ± 0.67; p=0.043, –0.47 ± 0.61 vs. –0.97 ± 1.10; p=0.31). Our study suggests that early feeding of nutrient-enriched milk for VLBWI in the neonatal period may affect their growth.

Bone mineralization and growth are enhanced in preterm infants fed an isocaloric, nutrient-enriched preterm formula through term

BACKGROUND

Because recent data on the effects of mineral concentrations in preterm infant formula on bone mineralization are lacking, recommendations for the mineral content of preterm infant formula differ greatly between committees.

OBJECTIVE

The goal of the study was to assess the effects of an isocaloric, nutrient-enriched preterm formula, which was fed from the age when full enteral feedings were tolerated through expected term, on bone mineralization in preterm infants.

DESIGN

We conducted a prospective, randomized, double-blind study in healthy, preterm infants (gestational age of 28-32 wk) who were fed either a control preterm formula (n=20) or an isocaloric, nutrient-enriched preterm formula (n=21) until 3 mo of age (ie, approximate expected term). Serum calcium indexes were taken throughout the study, and bone mass was determined by using dual-energy X-ray absorptiometry at hospital discharge and expected term.

RESULTS

A total of 37 infants (experimental formula, n=19; control formula, n=18) completed the study. Compared with control subjects, infants fed the experimental formula had 25% and 40% higher intakes of calcium and phosphorus, respectively. Serum calcium, phosphorus, osteocalcin, and alkaline phosphatase concentrations and urinary collagen type I cross-linked N-telopetide concentrations were not significantly different between the groups at any time point. The bone mineral content of infants fed the experimental formula was 23% (P=0.039) and 35% (P=0.002) higher at hospital discharge and expected term, respectively.

CONCLUSIONS

Bone mineralization at hospital discharge and expected term was significantly higher in preterm infants fed the isocaloric, nutrient-enriched formula than in those fed control formula. Continuation of the experimental formula beyond hospital discharge, through expected term, further improved bone mineralization.

Growth, efficacy, and safety of feeding an iron-fortified human milk fortifier

OBJECTIVE

Survival rates for preterm infants who weigh between 501 and 1500 g at birth have continued to improve over time. In response to this continuing decrease in birth weight of surviving preterm infants, Enfamil Human Milk Fortifier has recently been reformulated to meet the nutritional requirements of these smaller, more rapidly growing infants. It now provides an increased protein level of 1.1 g/58 kJ, a decreased carbohydrate level of 0.2 g/58 kJ, and a combined linoleic and alpha-linolenic fatty acid content of 157 mg/58 kJ. As these very small preterm infants have an increased requirement for dietary iron, the fortifier has been supplemented with 1.44 mg/58 kJ of iron, an amount of iron similar to that provided in a typical iron-fortified term infant formula. An iron-fortified product obviates the need for administration of an iron supplement, a hyperosmolar-inducing intervention. The purpose of this prospective, double-blind, randomized, controlled study was to evaluate growth, safety, and efficacy in a population of very low birth weight (VLBW) preterm infants who received human milk fortified with either the reformulated iron-fortified powdered human milk fortifier test product (HMF-T) or a powdered commercially available human milk fortifier control product (HMF-C).

METHODS

Infants who weighed < or =1500 g, had a gestational age < or =33 weeks postmenstrual age, and had an enteral intake of at least 100 mL/kg per day of unfortified human milk were stratified by gender and birth weight and randomized to receive HMF-T or HMF-C product from study day 1 to study day 28, hospital discharge, or the termination of human milk feedings, whichever came first. Unless medically indicated, investigators were not to administer iron supplements from study days 1 to 14. Infants were assessed serially for growth; enteral and parenteral intake; serum chemistry and hematologic values; clinical histories, including the administration of blood transfusions; feeding tolerance; respiratory outcomes; and morbidities, including adverse events.

RESULTS

Of the 181 participating infants in this study, 96 received HMF-T and 85 received HMF-C. At randomization, there were no significant differences in infant characteristics between the fortifier groups. The percentage of participants who remained in the study for 28 days was similar between fortifier groups (57% HMF-T, 46% HMF-C). For both fortifier groups, the most frequent reasons for discontinuing the study before study day 28 were unavailability of human milk and hospital discharge. Rate of weight gain was similar between the fortifier groups (17.5 +/- 0.53 g/kg per day for HMF-T and 17.3 +/- 0.59 g/kg per day for HMF-C). Mean achieved weight, length, and head circumference were comparable between groups across the 28-day study period. Total protein intake from enteral and parenteral nutrition was significantly greater for the HMF-T fortifier group; however, this difference did not result in any difference in growth between the 2 fortifier groups. An analysis of the growth and energy intake data of a subset of the intent-to-treat population who adhered more strictly to the study feeding protocol yielded results similar to those seen for the intent-to-treat population. There were no clinically significant differences in the results of laboratory studies between the groups at study days 0, 14, and 28. Anemia of prematurity was prevalent in both study groups; by study day 28, median hematocrit levels were 27.0% (interquartile range [IQR]: 24.0%-29.6%) for the HMF-T group and 26.0% (IQR: 24.0%-31.0%) for the HMF-C group. Median ferritin levels were 77.0 ng/mL (IQR: 37-155 ng/ml) for HMF-T and 92.0 ng/mL (IQR: 33-110 ng/mL) for HMF-C. There were no significant differences between the study fortifier groups in regard to the receipt of medically indicated iron supplements on or before study day 14 or in the administration of blood transfusions before study day 0 or from study days 0 through 14. However, from study day 15 to study day 28, fewer HMF-T infants (n = 12) required a blood transfusion than did HMF-C infants (n = 20). Although the higher levels of iron in the HMF-T fortifier (1.44 mg vs 0.35 mg for HMF-C per 4 packets of powdered fortifier) did not prevent anemia per se, it did reduce the frequency of one of the most serious outcomes of anemia: the need for a blood transfusion. There was no statistically significant difference between fortifier groups in regard to feeding tolerance. Rates of suspected sepsis (26% HMF-T vs 31% HMF-C) and confirmed sepsis (5% HMF-T, 7% HMF-C) were low as were the rates of suspected necrotizing enterocolitis (NEC; 6% HMF-T and 5% HMF-C) and confirmed Bell's stage 2 or more NEC (1% HMF-T and 1% HMF-C). There were no statistically significant differences between the study fortifier groups in regard to the incidence of confirmed and suspected sepsis and NEC.

CONCLUSION

Both human milk fortifiers studied are safe, are well tolerated, and facilitate comparable good growth; however, using the iron-fortified product may reduce the need for blood transfusions in VLBW infants. The similar low rates of suspected and confirmed NEC and sepsis seen in both fortifier groups in this study refutes the premise that the inclusion of iron in fortifiers will increase the incidence of sepsis and NEC. Indeed, the incidence for NEC and sepsis for both groups in this study was lower than is reported for VLBW infants and similar to that seen for infants who are fed human milk.

New perspectives on nutrition enhance outcomes for premature infants

Significant advances have occurred during the past 20 years in the understanding of the complex relationships of the environment, the developing gut-associated immune system, the bacterial flora, the barrier functions of the gut, and the effects of nutrient intake. These advances have produced a profoundly different way of interpreting the nutritional requirements for normal growth and development of premature infants throughout their entire life.