Effect of neonatal caloric deprivation on head growth and 1-year developmental status in preterm infants

Association of Growth During Infancy With Neurodevelopment and Obesity in Children Born Very Preterm: The Environmental influences on Child Health Outcomes Cohort

OBJECTIVE

To evaluate associations between change in weight z-score after neonatal intensive care unit (NICU) discharge and neurodevelopmental outcomes and obesity at 12-48 months of age among individuals born very preterm.

STUDY DESIGN

This secondary analysis used data from infants born very preterm participating in the Environmental influences on Child Health Outcomes cohort (n=1400). Growth during infancy was calculated as change in weight z-score between NICU discharge and follow-up at a mean of 27 months of age. Very low weight gain was defined as a change in weight z-score <-1.67; very high weight gain was a change in weight z-score >1.67. Neurodevelopmental outcomes included the Bayley Scales of Infant and Toddler Development, Child Behavior Checklist 1.5-5 years, and Modified Checklist for Autism in Toddlers. Multivariable linear regression was used to estimate associations between increase in weight z-score and neurodevelopmental outcomes.

RESULTS

Very low weight gain between NICU discharge and follow-up (experienced by 6.4% of participants) was associated with lower scores on cognitive (adjusted mean difference: -4.26; 95% confidence interval: -8.55, -0.04) and language (adjusted mean difference: -4.80; 95% confidence interval: -9.70, -0.11) assessments. Very high weight gain (experienced by 13.6% of participants) was associated with an increased obesity risk (adjusted relative risk: 6.20; 95% confidence interval: 3.99, 9.66) but not with neurodevelopmental outcomes.

CONCLUSIONS

Very high weight gain in the first 12-48 months after NICU discharge was associated with a higher risk of obesity at follow-up; very low weight gain was associated with lower scores on cognitive and language assessments.

Extrauterine Growth Restriction: Need for an Accurate Definition

Neonates show considerable variation in growth that can be recognized through serial measurements of basic variables such as weight, length, and head circumference. If possible, measurement of subcutaneous and total body fat mass can also be useful. These biometric measurements at birth may be influenced by demographics, maternal and paternal anthropometrics, maternal metabolism, preconceptional nutritional status, and placental health. Subsequent growth may depend on optimal feeding, total caloric intake, total metabolic activity, genetic makeup, postnatal morbidities, medications, and environmental conditions. For premature infants, these factors become even more important; poor in utero growth can be an important reason for spontaneous or induced preterm delivery. Later, many infants who have had intrauterine growth restriction (IUGR) and are born small for gestational age (SGA) continue to show suboptimal growth below the 10th percentile, a condition that has been defined as extrauterine growth restriction (EUGR) or postnatal growth restriction (PNGR). More importantly, a subset of these growth-restricted infants may also be at high risk of abnormal neurodevelopmental outcomes. There is a need for well-defined criteria to recognize EUGR/PNGR, so that correctional steps can be instituted in a timely fashion.

Weight, length, and head circumference at 36 weeks are not predictive of later cognitive impairment in very preterm infants

OBJECTIVE

To assess diagnostic accuracy of 36-week anthropometric weight, length, and head circumference <10th and <3rd percentiles to predict preterm infant cognitive impairment.

STUDY DESIGN

Cohort study of 898 preterm <30-week very-low-birth weight (<1500 g) infants. Anthropometric measures' accuracy to predict cognitive impairment (Bayley-III Cognitive Composite score) <80, 21-months corrected age (CA) and Wechsler Preschool and Primary Scale of Intelligence Quotient (intellectual outcomes) <70, 36-months CA, were determined using receiver operating characteristic (ROC) curves.

RESULT

Thirty-six-week weight, length or head circumference <10th or <3rd percentile did not predict cognitive impairment; areas under ROC curves were <0.6. Sensitivities and specificities for 10th and 3rd percentile cut points were all poor, with most not exceeding 70%, whether the Fenton 2013 or INTERGROWTH 2015 growth charts were used. Brain injury and low maternal education were better predictors of cognitive impairment.

CONCLUSION

Preterm infant 36-week anthropometric measurements are not accurate predictors of cognitive impairment.

High Early Parenteral Lipid in Very Preterm Infants: A Randomized-Controlled Trial

OBJECTIVE

To determine whether high early parenteral soybean oil lipid intake in very low birth weight (VLBW) infants in the first week after birth decreases the proportion of weight loss and subsequently the incidence of extrauterine growth restriction (EUGR).

STUDY DESIGN

This was a randomized controlled trial of appropriate for gestational- ge VLBW infants. Lipid intake in the control group started at 0.5-1 g/kg per day and increased daily by 0.5-1 g/kg per day till reaching 3 g/kg per day. The intervention group was started on 2 g/kg per day that increased to 3 g/kg per day the following day.

RESULTS

Of the 176 infants assessed for eligibility, 83 were included in the trial. Infants in the intervention group were started on lipid sooner (13.8 ± 7.8 vs 17.5 ± 7.8 hour; P = .03) and had higher cumulative lipid intake in the first 7 days of age (13.5 ± 4.2 vs 10.9 ± 3.5 g/kg per day; P = .03). Infants in the intervention group had a lower percentage of weight loss (10.4 vs 12.7%; P = .02). The mean triglyceride level was higher in the intervention group (1.91 ± 0.79 vs 1.49 ± 0.54 mmol/L; P = .01), however, hypertriglyceridemia was similar between the 2 groups. The incidence of EUGR was lower in the intervention group (38.6% vs 67.6%; P = .01). Head circumference z score was higher in the intervention group (-1.09 ± 0.96 vs -1.59 ± 0.98; P = .04).

CONCLUSIONS

In VLBW infants, provision of a high early dose of parenteral lipid in the first week of age results in less weight loss and lower incidence of EUGR.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT03594474.

Head Circumference Growth Is Enhanced by SMOFlipid in Preterm Neonates

BACKGROUND

Suboptimal fat intake during the early postnatal weeks significantly affects brain growth and maturation. Studies to date have focused on the quantity rather than the quality of fat intake.

OBJECTIVE

We hypothesized that early nutrition of premature neonates should also include optimization of the type of fat intake, and thus those receiving SMOFlipid, a balanced multicomponent lipid emulsion, would have improved head growth as measured by head circumference (HC) at discharge.

STUDY DESIGN

We retrospectively reviewed HC in infants weighing <1,500 g who were hospitalized for two or more weeks during a 20-month period, in which all preterm infants received fat as Lipofundin, and the following 20-month period, in which all such infants received SMOFlipid.Lipids were dosed up to 3 g/kg/day and reduced as enteral nutrition progressed. Parenteral fish oil (Omegaven) was permitted as rescue therapy during both periods.

RESULTS

Period 2 infants had better head growth (0.79 [0.69,0.90] vs. 0.75 [0.64,0.86] cm/week; p = 0.0158). More infants reached discharge with an HC of ≥50 percentile (51 vs. 31%; p = 0.0007), and fewer infants had an HC of ≤3 percentile (11 vs. 14%; p = 0.023). Median length of stay was reduced by more than 1 week.A multivariable regression was performed using the weekly increase in HC as the dependent variable, and the time epoch, birth weight, gestational age, hospitalization days, and gender as independent variables. Only the time epoch and days of hospitalization were significant (both p < 0.0001).

CONCLUSION

Our data offer preliminary evidence of improved brain growth in those receiving a balanced lipid emulsion as compared with a soybean oil emulsion.

"Extrauterine growth restriction" and "postnatal growth failure" are misnomers for preterm infants

Preterm infants are increasingly diagnosed as having "extrauterine growth restriction" (EUGR) or "postnatal growth failure" (PGF). Usually EUGR/PGF is diagnosed when weight is <10th percentile at either discharge or 36-40 weeks postmenstrual age. The reasons why the phrases EUGR/PGF are unhelpful include, they: (i) are not predictive of adverse outcome; (ii) are based only on weight without any consideration of head or length growth, proportionality, body composition, or genetic potential; (iii) ignore normal postnatal weight loss; (iv) are usually assessed prior to growth slowing of the reference fetus, around 36-40 weeks, and (v) are usually based on an arbitrary statistical growth percentile cut-off. Focus on EUGR/PGF prevalence may benefit with better attention to nutrition but may also harm with nutrition delivery above infants' actual needs. In this paper, we highlight challenges associated with such arbitrary cut-offs and opportunities for further refinement of understanding growth and nutritional needs of preterm neonates.

Early caloric deprivation in preterm infants affects Bayley-III scales performance at 18-24 months of corrected age

BACKGROUND

Adequate nutrition is essential for optimal neurodevelopment to preterm infants. Our aim was to evaluate the impact of caloric deprivation on Bayley-III scales performance at 18-24 months of corrected age, in a cohort of preterm infants.

METHODS

We prospectively enrolled infants with gestational age <30 weeks and birth weight <1500 g. Apart from a whole cohort analysis, we performed a subgroup analysis between infants received inadequate calories (<85 Kcal/kg/day) during the first two weeks of age, compared to a standard nutrition group. All infants underwent a Bayley-III assessment at 18-24 months of corrected age.

RESULTS

From the 63 preterm infants analysed, 25% had caloric deprivation compared to 75% with adequate nutrition. Caloric deprived infants were of lower gestational age and birth weight, and received a lower amount of enteral feeding during the first 14 days of age. There were no differences between the two groups regarding the common neonatal co-morbidities. Caloric deprived infants had significantly lower composite index scores at 18-24 months of corrected age. Caloric deprivation, late onset sepsis, necrotizing enterocolitis, and bronchopulmonary dysplasia were significant risk factors of neurodevelopmental impairment.

CONCLUSIONS

Several neonatal factors affect the neurodevelopmental outcome of preterm infants, and nutrition may pose an important role.

Optimizing nutrition of the preterm infant

The goal of nutrition of the preterm infant is to meet the growth rate of the healthy fetus of the same gestational age and to produce the same body composition of the healthy fetus in terms of organ growth, tissue components, and cell number and structure. Nutritional quantity and quality are fundamental for normal growth and development of preterm infants, including neurodevelopmental outcomes. Failure to provide the necessary amounts of all of the essential nutrients has produced not only growth failure, but also increased morbidity and less than optimal neurodevelopment. Growth velocities during the NICU hospitalization period for preterm infants exert a significant effect on neurodevelopmental and anthropometric outcomes. Despite the obvious need for optimal nutrition, growth failure is almost universal among preterm infants. There is every reason, therefore, to optimize nutrition of the preterm infant, in terms of total energy and protein, but also in terms of individual components such as amino acids, specific carbohydrates and lipids, and even oxygen. This review presents scientific rationale for nutrient requirements and practical guidelines and approaches to intravenous and enteral feeding for preterm infants. Intravenous feeding, including amino acids, should be started right after birth at rates that are appropriate for the gestational age of the infant. Enteral feeding should be started as soon as possible after birth, using mother's colostrum and milk as first choices. Enteral feeding should begin with trophic amounts and advanced as rapidly as tolerated, decreasing IV nutrition accordingly, while maintaining nutrient intakes at recommended rates. Feeding protocols are valuable for improving nutrition and related outcomes. Further research is needed to determine the optimal nutrition and rate of growth in preterm infants that will achieve optimal neurocognitive benefits while minimizing the longer-term risk of chronic diseases.

How Close Are We to Achieving Energy and Nutrient Goals for Very Low Birth Weight Infants in the First Week?

BACKGROUND

Emerging evidence suggests intakes of protein and energy as early as the first week of life in preterm very low birth weight (VLBW) infants are associated with improved neurodevelopment. In response, many neonatal intensive care units (NICUs) have launched new, more aggressive early feeding guidelines. The aim of this study was to evaluate enteral and parenteral energy and macronutrient intakes during the first postnatal week in VLBW infants admitted to NICUs that have introduced more aggressive early feeding guidelines.

MATERIALS AND METHODS

Estimated energy and macronutrient intakes were prospectively collected from VLBW infants fed exclusively mother's own milk and/or parenteral nutrition and compared with expert recommendations. Days to reach full enteral feeds (150 mL/kg/d) and discharge anthropometrics were examined.

RESULTS

By days 6 and 7, median protein and lipid intakes, respectively, reached recommended values (3.5 and 3.0 g/kg/d). However, by day 8, many infants remained below recommended intakes for protein (34%), lipid (34%), carbohydrate (68%), and energy (71%). Late-onset sepsis was associated with a decreased likelihood of reaching full enteral feeds on any given day (hazard ratio, 0.2; 95% confidence interval, 0.1-0.5; P ≤ .0009). There was no significant relationship between week 1 nutrient intakes and anthropometrics at discharge.

CONCLUSION

Despite the introduction of more aggressive early feeding guidelines and improved energy and nutrient intakes compared with literature values, many VLBW infants remain below recommended nutrition goals in the first week.

Head growth of undernourished children in rural Nepal: association with demographics, health and diet

BACKGROUND

Brain development in early childhood is a key determinant of later cognition, social achievement and educational success. Head circumference (HC) measurements are a simple method to assess brain growth, yet reports of these measurements are uncommon in nutritional surveys of undernourished children.

OBJECTIVE

To evaluate HC measurements in a population of rural Nepali children and relate these measurements to demographics, health and diet.

METHODS

An observational study of head growth was nested within a longitudinal evaluation of a livestock-based agricultural intervention in rural Nepal. Between 538 and 689 children (aged 6 months to 8 years) were measured (height, weight, HC) at each of six survey visits. A total of 3652 HC measurements were obtained. Results were converted to Z-scores (WHO Anthro).

RESULTS

Mean head circumference Z-scores (HCZ) diminished progressively over the first 4 years of life; a decline of 30% occurred between 3 and 4 years of age (-1.73 to -2.45, P < 0.0001). Overall, 56% of HCZ were <-2. Gender-adjusted HCZ (but not other measurements) were significantly lower for girls than boys [mean (SD) -2.31 (1.0) vs -1.99 (0.094), P < 0.0001]; girls more often had microcephaly (61% vs 50%, P < 0.0001). For children <3 years of age, HCZ were better in those who had eaten two or more animal-source foods (ASFs) within the previous 24 h [-1.69 (.05) vs -2.08 (0.10), P = 0.001] than in those who had eaten none or only one; HCZ correlated with the number of ASFs consumed (P < 0.001). Regression analyses demonstrated that the main determinants of HCZ were age, weight-for-age Z-scores (WAZ) and gender; 43% of the variance in HCZ in younger children was explained by WAZ and ASF consumption.

CONCLUSION

HCs reflect brain size in young children; brain size is linked to cognitive function. Poor head growth represents another facet of the 'silent emergency' of child undernutrition. Routine HCZ assessments may contribute to better understanding of the links between poverty and cognitive development.

The Impact of Neonatal Illness on Nutritional Requirements-One Size Does Not Fit All

Sick neonates are at high risk for growth failure and poorer neurodevelopment than their healthy counterparts. The etiology of postnatal growth failure in sick infants is likely multi-factorial and includes undernutrition due to the difficulty of feeding them during their illness and instability. Illness also itself induces fundamental changes in cellular metabolism that appear to significantly alter nutritional demand and nutrient handling. Inflammation and physiologic stress play a large role in inducing the catabolic state characteristic of the critically ill newborn infant. Inflammatory and stress responses are critical short-term adaptations to promote survival, but are not conducive to promoting long-term growth and development. Conditions such as sepsis, surgery, necrotizing enterocolitis, chronic lung disease and intrauterine growth restriction and their treatments are characterized by altered energy, protein and micronutrient metabolism that result in nutritional requirements that are different from those of the healthy, growing term or preterm infant.

Protein intake and neurodevelopmental outcomes

There is a compelling body of literature that suggests that the provision of an inadequate amount of protein to preterm infants in the neonatal period has detrimental effects on the developing brain with the potential to result in long-term, neurodevelopmental sequelae. Although a great deal of indirect evidence implies that the provision of adequate amounts of protein may be associated with better neurodevelopmental outcomes, there remains a paucity of direct evidence that would allow us to draw any final conclusions.

Methods to quantify soft tissue-based cranial growth and treatment outcomes in children: a systematic review

Context

Longitudinal assessment of cranial dimensions of growing children provides healthcare professionals with information about normal and deviating growth as well as treatment outcome.

Objective

To give an overview of soft tissue–based methods for quantitative longitudinal assessment of cranial dimensions in children until age 6 years and to assess the reliability of these methods in studies with good methodological quality.

Data source

PubMed, EMBASE, Cochrane Library, Web of Science, Scopus, and CINAHL were searched. A manual search was performed to check for additional relevant studies.

Study selection

Primary publications on facial growth and treatment outcomes in children younger than age 6 years were included.

Data extraction

Independent data extraction was performed by two observers. A quality assessment instrument was used to determine methodological quality. Methods used in studies with good methodological quality were assessed for reliability expressed as the magnitude of the measurement error and the correlation coefficient between repeated measurements.

Results

In total, 165 studies were included, forming three groups of methods: head circumference anthropometry, direct anthropometry, and 2D photography and 3D imaging techniques (surface laser scanning and stereophotogrammetry). In general, the measurement error was below 2 mm, and correlation coefficients were very good.

Conclusion

Various methods for measuring cranial dimensions have shown to be reliable. Stereophotogrammetry is the most versatile method for quantitative longitudinal assessment of cranial dimensions and shapes in children. However, direct anthropometry continues to be the best method for routine clinical assessments of linear cranial dimensions in growing children until age 6 years.

Early amino acid administration in very preterm infants: Too little, too late or too much, too soon?

Early postnatal growth failure is well described in very preterm infants. It reflects the nutritional deficits in protein and energy intake that accumulate in the first few weeks after birth. This coincides with the period of maximum parenteral nutrition (PN) dependency, so that protein intake is largely determined by intravenous amino acid (AA) administration. The contribution of PN manufacture, supply, formulation, prescribing and administration to the early postnatal nutritional deficit is discussed, focusing on total AA intake. The implications of postnatal deficits in AA and energy intake for growth are reviewed, with particular emphasis on early head/brain growth and long-term neurodevelopmental outcome. The rationale for maximising AA acid intake as soon as possible after birth is explained. This includes the benefits for very early postnatal nutritional intake and metabolic adaptation after birth. These benefits relate to total AA intake and so have to be interpreted with some caution, given the very limited evidence base surrounding the balance of individual AAs in neonatal PN formulations. This work mostly predates current nutritional recommendations and therefore may not provide a true reflection of individual AA utilisation in current clinical practice.

From parenteral to enteral nutrition: a nutrition-based approach for evaluating postnatal growth failure in preterm infants

BACKGROUND

Nutrition practices for preterm infants include phases of parenteral nutrition (PN), full enteral nutrition (EN), and the transitional phase in between. Our aim was to identify the nutrition phases during which infants are most likely to exhibit poor growth that would affect risk for growth failure (GF) at discharge and to examine factors associated with GF.

METHODS

A retrospective chart review was conducted on infants born <32 weeks' gestation. The neonatal intensive care unit stay was divided into 3 nutrition phases: (1) full PN, (2) transitional PN + EN, and (3) full EN. Weekly growth rates were calculated, and for each growth velocity <10 g/kg/d, the coinciding phase was recorded. GF was defined as a discharge weight below the 10th percentile. The nutrition phases during which growth inadequacy predicted GF at discharge were determined, correcting for other clinical factors associated with GF.

RESULTS

In total, 156 eligible infants were identified. Seventy-six infants (49%) were discharged with weights <10%. Incidence of poor growth was highest during the transitional phase (46%) and was predictive of GF when adjusted for gestational age, birth weight, and severity of illness. Although energy intakes during the transitional phase were comparable to baseline parenteral provision, protein intakes progressively decreased ( P < .0001), consistently providing 3 g/kg/d as PN was weaned. Serum urea nitrogen also declined and was correlated with protein intake (r = -0.32, P < .001).

CONCLUSION

Growth was compromised during the transitional phase, likely related to decreased protein intake. Optimizing protein provision while PN is weaned is an important strategy to prevent postnatal growth failure.

Three-dimensional digital capture of head size in neonates - a method evaluation

Introduction

The quality of neonatal care is mainly determined by long-term neurodevelopmental outcome. The neurodevelopment of preterm infants is related to postnatal head growth and depends on medical interventions such as nutritional support. Head circumference (HC) is currently used as a two-dimensional measure of head growth. Since head deformities are frequently found in preterm infants, HC may not always adequately reflect head growth. Laser aided head shape digitizers offer semiautomatic acquisition of HC and cranial volume (CrV) and could thus be useful in describing head size more precisely.

Aims

1) To evaluate reproducibility of a 3D digital capture system in newborns. 2) To compare manual and digital HC measurements in a neonatal cohort. 3) To determine correlation of HC and CrV and predictive value of HC.

Methods

Within a twelve-month period data of head scans with a laser shape digitizer were analysed. Repeated measures were used for method evaluation. Manually and digitally acquired HC was compared. Regression analysis of HC and CrV was performed.

Results

Interobserver reliability was excellent for HC (bias-0.005%, 95% Limits of Agreement (LoA) −0.39–0.39%) and CrV (bias1.5%, 95%LoA-0.8–3.6%). Method comparison data was acquired from 282 infants. It revealed interchangeability of the methods (bias-0.45%; 95%LoA-4.55–3.65%) and no significant systematic or proportional differences. HC and CrV correlated (r² = 0.859, p<0.001), performance of HC predicting CrV was poor (RSD ±24 ml). Correlation was worse in infants with lower postmenstrual age (r² = 0.745) compared to older infants (r² = 0.843).

Discussion

The current practice of measuring HC for describing head growth in preterm infants could be misleading since it does not represent a 3D approach. CrV can vary substantially in infants of equal HC. The 3D laser scanner represents a new and promising method to provide reproducible data of CrV and HC. Since it does not provide data on cerebral structures, additional imaging is required.

Enterale Ernährung von Frühgeborenen

Unmittelbar postnatal ist bei Frühgeborenen der rasche Beginn einer vollständigen parenteralen Ernährung zur Fortsetzung des physiologischen intrauterinen umbilikalen Nährstofftransports notwendig, da die Energiereserven gering sind, Katabolismus verhindert werden soll und die Entwicklung des Gehirns nicht beeinträchtigt werden darf (Huppi 2008). Bei einem 1000 g schweren Frühgeborenen beträgt die zirkulierende Glukosemenge ca. 0,15 g und ist nach ca. 8 min verbraucht; der Glykogenspeicher beträgt 5 g und reicht etwa 5 h.

Early lipid supply and neurological development at one year in very low birth weight (VLBW) preterm infants

BACKGROUND

The rapid growth of the developing brain during early post-natal life makes it particularly vulnerable to a nutritional deficit. The neurological development of the very low birth weight preterm infant could be related to early lipid supply.

AIMS

To evaluate in preterm infants of gestational age ≤ 28 weeks of amenorrhea (WA) the relations between the neurological development determined at a corrected age of one year using the test of Brunet-Lézine and 1) the cumulative intakes of proteins, carbohydrates, lipids and energy during the first 28 days of life and 2) the weight gain in the first 28 days of life.

MATERIALS AND METHODS

Study of a mono-centric cohort of 48 premature infants of gestational age ≤ 28 WA consecutively hospitalized and followed longitudinally up to a corrected age of one year.

RESULTS

In simple univariate analysis, there was a significant correlation between the developmental quotient (DQ) at a corrected age of one year and the cumulative intake of energy and lipids at 14 days of life (p=0.02, p=0.01, respectively), the number of days to reach the minimum weight (p=0.02) and the weight gain from birth to D28 of life (p=0.04). There was no correlation between the DQ and early intake of proteins or carbohydrates. In multivariate analysis, only the association between the DQ at one year of corrected age and the cumulative lipid intake at 14 days of life remained statistically significant (p=0.04).

CONCLUSION

Our study demonstrates the importance of early lipid supply during the first two weeks of life for the neurological development at a corrected age of one year of very low birth weight preterm infants.

Early nutrition mediates the influence of severity of illness on extremely LBW infants

To evaluate whether differences in early nutritional support provided to extremely premature infants mediate the effect of critical illness on later outcomes, we examined whether nutritional support provided to "more critically ill" infants differs from that provided to "less critically ill" infants during the initial weeks of life, and if, after controlling for critical illness, that difference is associated with growth and rates of adverse outcomes. One thousand three hundred sixty-six participants in the NICHD Neonatal Research Network parenteral glutamine supplementation randomized controlled trial who were alive on day of life 7 were stratified by whether they received mechanical ventilation for the first 7 d of life. Compared with more critically ill infants, less critically ill infants received significantly more total nutritional support during each of the first 3 wk of life, had significantly faster growth velocities, less moderate/severe bronchopulmonary dysplasia, less late-onset sepsis, less death, shorter hospital stays, and better neurodevelopmental outcomes at 18-22 mo corrected age. Rates of necrotizing enterocolitis were similar. Adjusted analyses using general linear and logistic regression modeling and a formal mediation framework demonstrated that the influence of critical illness on the risk of adverse outcomes was mediated by total daily energy intake during the first week of life.

Brains versus brawn: an empirical test of Barker's brain sparing model

The Barker model of the in utero origins of diminished muscle mass in those born small invokes the adaptive "sparing" of brain tissue development at the expense of muscle. Though compelling, to date this model has not been directly tested. This article develops an allometric framework for testing the principal prediction of the Barker model-that among those born small muscle mass is sacrificed to spare brain growth-then evaluates this hypothesis using data from the third National Health and Nutrition Examination Survey (NHANES III). The results indicate clear support for a negative relationship between the allometric development of the two tissues; however, a further consideration of conserved mammalian fetal circulatory patterns suggests the possibility that system-constrained patterns of developmental damage and "bet-hedging" responses in affected tissues may provide a more adequate explanation of the results. Far from signaling the end of studies of adaptive developmental programming, this perspective may open a promising new avenue of inquiry within the fields of human biology and the developmental origins of health and disease.

Early head growth: relation with IQ at 8 years and determinants in term infants of low and appropriate birthweight

AIM

To investigate the relation between head growth at different periods and IQ at 8 years, and to identify factors associated with more rapid head growth.

METHOD

Two parallel cohorts of term low birthweight (LBW) and appropriate birthweight (ABW) infants were enrolled at birth in northeast Brazil. Anthropometric measurements were made at birth, 2 months, 6 months, 12 months, 24 months, and 8 years. Cognition was assessed at 8 years (n=164) with the Wechsler Intelligence Scale for Children. Multivariable analysis with a two-stage residual model was used to relate head growth between successive time points with IQ.

RESULTS

Mean birthweight was 2.35kg (SD 0.15) in the LBW group (33 males, 50 females), and 3.21kg (SD 0.15) in the ABW group (28 males, 53 females). Mean gestational age was 38.8 weeks (SD 1.4) and 40.0 weeks (SD 1.3) respectively. In the LBW group, head growth from birth to 2 months and from 2 to 6 months, conditional on previous size, were significant independent predictors of IQ at 8 years. Conditional head growth from 6 months to 8 years and head size at birth were unrelated to IQ. In the ABW group there was no significant relation between conditional head growth and IQ for any period. Determinants of more rapid head growth from birth to 6 months in LBW infants were maternal height and rate of infant weight gain.

INTERPRETATION

Head growth from birth to 6 months in term LBW infants is more important than prenatal or later postnatal head growth in predicting IQ at 8 years.

Indices of body and brain size at birth and at the age of 2 years: relations to cognitive outcome at the age of 16 years in low birth weight infants

OBJECTIVE

To determine in low birth weight infants the relations of being small for gestational age at birth, microcephalic at birth, low weight for age at 2 years, and microcephalic at 2 years to full scale intelligence quotient (FSIQ) at the age of 16 years.

METHODS

A prospective observational study of 422 of 837 eligible nondisabled low birth weight (<2000 g) adolescents from the newborn brain hemorrhage cohort with weight and head circumference at birth and at the age of 2 years in whom FSIQ was assessed with the Wechsler Abbreviated Scales of Intelligence at the age of 16 years.

RESULTS

In a multiple regression analysis, being small for gestational age (beta = -0.14, p = .02) and microcephalic at 2 years (beta = -0.18, p < .001), but not low weight for age at 2 years or microcephaly at birth, had significant independent effects on 16-year FSIQ. After adjusting for pre-, peri-, and postnatal risk factors for poor cognitive performance, the independent effects of being small for gestational age (beta = -0.13, p = .004) and microcephalic at 2 years (beta = -0.13, p = .01) persisted. In this analysis, birth social risk had the largest significant independent effect on 16-year FSIQ (beta = -0.28, p < .001).

CONCLUSIONS

Being small for gestational age at birth, but not low weight for age at 2 years, and microcephaly at 2 years, but not at birth, were independently related to FSIQ of nondisabled low birth weight adolescents, both with and without control for pre-, peri-, and postnatal risk factors.

Hindmilk: a head start in preterm nutrition

BACKGROUND

During the neonatal period, nutrition has a crucial impact on preterm infants' survival, growth and development. Current nutritional practices for preterm infants often fail to meet their nutritional needs and thus have potential adverse consequences for their growth and development. Hindmilk represents a promising avenue to manage this nutritional challenge.

METHOD

The scientific literature was reviewed to determine the current state of knowledge about hindmilk and its effects on the growth and development of preterm infants.

RESULTS

Four studies evaluating the effects of hindmilk on the growth of preterm infants were found and included in this review. These studies report contradictory findings and present serious methodological shortcomings, limiting the evidence on the potential benefits of hindmilk in preterm infants.

CONCLUSIONS

A body of knowledge on the effects of hindmilk on the growth and development of preterm infants is accumulating but there is still a striking need for further investigation.

First-week protein and energy intakes are associated with 18-month developmental outcomes in extremely low birth weight infants

OBJECTIVE

We sought to evaluate the association between early protein and energy intake and neurodevelopment and growth of extremely low birth weight (<1000 g) infants.

STUDY DESIGN

Daily protein and energy intakes were collected by chart review for the first 4 weeks of life on 148 extremely low birth weight survivors. A total of 124 infants (84%) returned for evaluation at 18 months' corrected age. Bivariate analysis tested correlations between weekly protein or energy intakes and Bayley Mental Development Index, Psychomotor Development Index, or growth at 18 months. Separate regression models evaluated contributions of protein (grams per kilogram per day) and energy intake (kilojoules per kilogram per day) to the Mental Development Index, Psychomotor Development Index, and growth, while controlling for known confounders.

RESULTS

After adjusting for confounding variables, week 1 energy and protein intakes were each independently associated with the Mental Development Index. During week 1, every 42 kJ (10 kcal)/kg per day were associated with a 4.6-point increase in the Mental Development Index and each gram per kilogram per day in protein intake with an 8.2-point increase in the Mental Development Index; higher protein intake was also associated with lower likelihood of length <10th percentile.

CONCLUSIONS

Increased first-week protein and energy intakes are associated with higher Mental Development Index scores and lower likelihood of length growth restrictions at 18 months in extremely low birth weight infants. Emphasis should be placed on providing more optimal protein and energy during this first week.

High-energy and -protein diet increases brain and corticospinal tract growth in term and preterm infants after perinatal brain injury

OBJECTIVE

Our hypothesis was that infants with perinatal brain injury fail to thrive in the first postnatal year because of increased energy and protein requirements from deficits that accumulated during neonatal intensive care. Our aim was to assess whether dietary energy and protein input was a rate-limiting factor in brain and body growth in the first year after birth.

METHODS

We conducted a prospective, double-blind and randomized, 2-stage group sequential study and controlled for gestation, gender, and brain lesion. Neonates with perinatal brain damage were randomly allocated to receive either a high- (120% recommended average intake) or average (100% recommended average intake) energy and protein diet. The study began at term and continued for 12 months. Three-day dietary diaries estimated energy and protein intake. The primary outcome measure was growth of occipitofrontal circumference. Other measures were growth of axonal diameters in the corticospinal tract, which were estimated by using transcranial magnetic stimulation, weight gain, and length.

RESULTS

The study was terminated at the first analysis when the 16 subjects had completed the protocol, because the predetermined stopping criterion of >1 SD difference in occipitofrontal circumference at 12 months' corrected age in those receiving the higher-energy and -protein diet had been demonstrated. Axonal diameters in the corticospinal tract, length, and weight were also significantly increased.

CONCLUSIONS

These data support our hypothesis that infants with significant perinatal brain damage have increased nutritional requirements in the first postnatal year and suggest that decreased postnatal brain growth may exacerbate their impairment. There are no measures of cognitive ability at 12 months of age, and whether there will be any improvement in the status of these children, therefore, remains to be shown.

The corrected blood urea nitrogen predicts the developmental quotient of extremely low-birth-weight infants at the corrected age of 36 months

BACKGROUND

Currently, there are no nutritional indices to predict cognitive function in extremely low-birth-weight (ELBW) infants.

OBJECTIVE

To assess the neonatal blood urea nitrogen (BUN) values in ELBW infants according to their cognitive function at the corrected age of 36 months.

METHODS

This was a retrospective study that assessed the neonatal factors affecting the developmental outcome in two groups "developmental quotient (DQ)> or =80" and "DQ<80", the groups were divided based on the DQ at the corrected age of 36 months. Between 1996 and 1999, 178 ELBW infants born at <28 weeks of gestation were admitted to our neonatal intensive care unit (NICU), of these, 32 died. Of the surviving 146 infants, 37 infants without any exclusion criteria (that would affect the cognitive function and BUN) except the nutritional factor, were assessed. Area under the curve (AUC) of corrected BUN (CBUN: BUN x 0.5/serum creatinine) from 28 to 84 days of life was used as an index of protein intake.

RESULTS

No significant differences were observed between the two groups with regard to the gestational age, birth weight, Z score of birth weight, and sex. However, compared to 15 infants with DQ<80, 22 infants with DQ> or =80 had significantly shorter duration of artificial ventilation and O(2) supplementation, a higher Apgar score at 5 min, and a higher AUC of CBUN. On multiple regression analysis, DQ> or =80 was observed to be significantly correlated with the AUC of CBUN (Odd's ratio 1.03, 95% confidence interval: 1.002-1.06).

CONCLUSION

The CBUN level would provide an estimate of adequate protein intake and the subsequent development of an ELBW infant.

Using the LMS method to calculate z-scores for the Fenton preterm infant growth chart

OBJECTIVES

The use of exact percentiles and z-scores permit optimal assessment of infants' growth. In addition, z-scores allow the precise description of size outside of the 3rd and 97th percentiles of a growth reference. To calculate percentiles and z-scores, health professionals require the LMS parameters (Lambda for the skew, Mu for the median, and Sigma for the generalized coefficient of variation; Cole, 1990). The objective of this study was to calculate the LMS parameters for the Fenton preterm growth chart (2003).

DESIGN

Secondary data analysis of the Fenton preterm growth chart data.

METHODS

The Cole methods were used to produce the LMS parameters and to smooth the L parameter. New percentiles were generated from the smooth LMS parameters, which were then compared with the original growth chart percentiles.

RESULTS

The maximum differences between the original percentile curves and the percentile curves generated from the LMS parameters were: for weight; a difference of 66 g (2.9%) at 32 weeks along the 90th percentile; for head circumference; some differences of 0.3 cm (0.6-1.0%); and for length; a difference of 0.5 cm (1.6%) at 22 weeks on the 97th percentile.

CONCLUSION

The percentile curves generated from the smoothed LMS parameters for the Fenton growth chart are similar to the original curves. These LMS parameters for the Fenton preterm growth chart facilitate the calculation of z-scores, which will permit the more precise assessment of growth of infants who are born preterm.

Energy requirements

The determination of the appropriate energy and nutritional requirements of a newborn infant requires a clear goal of the energy and other compounds to be administered, valid methods to measure energy balance and body composition, and knowledge of the neonatal metabolic capacities. Providing an appropriate amount of energy to newborn infants remains a challenge considering the great number of newborn infants who suffer in-hospital growth retardation. The energy requirements of a newborn infant are influenced by several factors - basal metabolism, growth, energy expenditure, and energy losses - which change continuously during development. Calculating the energy requirements of preterm infants is subject to error if general recommendations are applied without recognition of the large variation in factors that influence, for example, energy expenditure. Therefore, energy recommendations should be individualized and preferably based on measurements of energy expenditure. In particular, extremely low birth-weight and very low birth-weight infants are prone to develop negative energy and nutrient balances, due to low energy intake, low energy reserves and high energy demands. Early energy accretion is not only essential for growth but also influences neurodevelopmental outcome and physical health in the long term, thereby underlining the importance of adequate neonatal nutrition.

Nutritional support in the premature newborn

The theory and practice of nutritional support in the premature newborn has assumed increasing importance with survival of greater numbers of very immature infants. After birth, many do not tolerate full enteral feeding until gastrointestinal motor function has matured. During this process some will develop necrotising enterocolitis (NEC), a devastating failure of adaptation to postnatal life that may result in death, or severe complications. The feeding strategy that minimises the risk of NEC remains to be defined. In addition, promoting growth rates and nutrient accretion equivalent to those achieved during fetal development while optimising neurodevelopmental and long term health outcomes represents an important challenge for neonatologists. This review will focus on the problems associated with enteral nutrition, the requirement for parenteral nutrition, and the long term consequences of early nutritional interventions, underlining the need for prolonged follow up in assessing the potential benefits of different approaches to feeding.

Subnormal head circumference in very low birth weight children: neonatal correlates and school-age consequences

BACKGROUND

Subnormal head circumference (HC) has been associated with poor neurologic and developmental outcomes.

AIM

To examine the correlates and consequences of subnormal HC in a cohort of school age, very low birth weight (VLBW, <1,500 g) children. STUDY DESIGN AND OUTCOME MEASURES: We examined developmental outcomes at a mean age of 6.8 years in a cohort of 128 VLBW children born from 1982-1986 and 58 normal birth weight controls. The VLBW cohort included a regional sample of <750 g birth weight children and matched children with 750-1,499 g birth weight. Outcomes included an IQ equivalent, neuropsychological skills, academic achievement, adaptive behavior, and attention problems. HC was defined along a continuum and as subnormal vs. normal. Linear and logistic regressions were employed to determine the effects of HC on the outcomes after controlling for confounding variables.

RESULTS

Thirty one VLBW children (24%) had subnormal HC vs. none of the controls. The VLBW children with subnormal HC differed significantly from the normal HC group in birth weight (748 g vs. 977 g, p<.001), SGA status (52% vs. 27%, p<.05), high neonatal risk (57% vs. 29%, p<.05), and neurosensory impairment (23% vs. 8%, p<.05). Even after taking these risk factors into account, subnormal HC was associated with poorer IQ equivalent, perceptual motor skills, academic achievement, and adaptive behavior. Results were similar after excluding the children with neurosensory impairment.

CONCLUSIONS

Subnormal HC is associated with adverse developmental outcomes in VLBW children, independent of other risk factors. Interventions to improve antenatal and postnatal growth may contribute to better school-age outcomes.

Feeding preterm infants after hospital discharge: a commentary by the ESPGHAN Committee on Nutrition

Survival of small premature infants has markedly improved during the last few decades. These infants are discharged from hospital care with body weight below the usual birth weight of healthy term infants. Early nutrition support of preterm infants influences long-term health outcomes. Therefore, the ESPGHAN Committee on Nutrition has reviewed available evidence on feeding preterm infants after hospital discharge. Close monitoring of growth during hospital stay and after discharge is recommended to enable the provision of adequate nutrition support. Measurements of length and head circumference, in addition to weight, must be used to identify those preterm infants with poor growth that may need additional nutrition support. Infants with an appropriate weight for postconceptional age at discharge should be breast-fed when possible. When formula-fed, such infants should be fed regular infant formula with provision of long-chain polyunsaturated fatty acids. Infants discharged with a subnormal weight for postconceptional age are at increased risk of long-term growth failure, and the human milk they consume should be supplemented, for example, with a human milk fortifier to provide an adequate nutrient supply. If formula-fed, such infants should receive special postdischarge formula with high contents of protein, minerals and trace elements as well as an long-chain polyunsaturated fatty acid supply, at least until a postconceptional age of 40 weeks, but possibly until about 52 weeks postconceptional age. Continued growth monitoring is required to adapt feeding choices to the needs of individual infants and to avoid underfeeding or overfeeding.

Growth in the neonatal intensive care unit influences neurodevelopmental and growth outcomes of extremely low birth weight infants

OBJECTIVES

The objectives of this study were to assess whether (1) in-hospital growth velocity is predictive of neurodevelopmental and growth outcomes at 18 to 22 months' corrected age among extremely low birth weight (ELBW) infants and (2) in-hospital growth velocity contributes to these outcomes after controlling for confounding demographic and clinical variables.

METHODS

Infants 501 to 1000 g birth weight from a multicenter cohort study were divided into quartiles of in-hospital growth velocity rates. Variables considered for the logistic-regression models included gender, race, gestational age, small for gestational age, mother's education, severe intraventricular hemorrhage, periventricular leukomalacia, age at regaining birth weight, necrotizing enterocolitis, late-onset infection, bronchopulmonary dysplasia, postnatal steroid therapy for pulmonary disease, and center.

RESULTS

Of the 600 discharged infants, 495 (83%) were evaluated at 18 to 22 months' corrected age. As the rate of weight gain increased between quartile 1 and quartile 4, from 12.0 to 21.2 g/kg per day, the incidence of cerebral palsy, Bayley II Mental Developmental Index (MDI) <70 and Psychomotor Developmental Index (PDI) <70, abnormal neurologic examination, neurodevelopmental impairment, and need for rehospitalization fell significantly. Similar findings were observed as the rate of head circumference growth increased. The in-hospital rate of growth was associated with the likelihood of anthropometric measurements at 18 months' corrected age below the 10th percentile values of the Centers for Disease Control and Prevention 2000 growth curve. Logistic-regression analyses, controlling for potential demographic or clinical cofounders, and adjusted for center, identified a significant relationship between growth velocity and the likelihood of cerebral palsy, MDI and PDI scores of <70, and neurodevelopmental impairment.

CONCLUSIONS

These analyses suggest that growth velocity during an ELBW infant's NICU hospitalization exerts a significant, and possibly independent, effect on neurodevelopmental and growth outcomes at 18 to 22 months' corrected age.

Interneonatal intensive care unit variation in growth rates and feeding practices in healthy moderately premature infants

BACKGROUND

Variation in care and outcomes of very low birth weight infants (VLBW) in neonatal intensive care units (NICU) has been widely reported in the past decade. Less is known about care provided to healthy premature infants born between 30 and 35 weeks gestational age (GA). We have previously reported inter-NICU variation in discharge (D/C) timing and achievement of maturational milestones in this population.

OBJECTIVE

To compare inter-NICU growth outcomes and feeding practices in healthy, moderately premature infants.

METHODS

Records of 450 infants, 30 to 35 weeks gestation, without medical or surgical complications, and consecutively discharged from 15 Massachusetts NICUs (nine Level II and six Level III) were reviewed. Final analyses included 382 infants with hospital length of stay >6 days (d).

RESULTS

GA at birth and birth weight (BW) were 33.2 weeks (SD 1.2) and 2024 g (389). Mean Z-score decreased 0.67z (0.37) from birth to D/C. Weight loss from birth to 7 d averaged 4.0%. Mean growth velocity from 7 d to D/C was 13.3 g/k/d (5.2) with net growth velocity of 5.5 g/k/d (5.6). Mean net growth velocity ranged from 0.1 to 8.4 g/k/d (p<0.001) among study NICUs. Time of initiation, rate of advancement and caloric density of feedings also varied significantly between NICUs.

CONCLUSION

Mean NICU growth velocity of healthy, moderately premature infants did not achieve in utero growth standards. There was significant inter-NICU variation in growth outcomes and feeding practices. Further study is needed to identify practices associated with better growth in this healthy moderately premature infant population.

Adverse neurodevelopmental outcomes among extremely low birth weight infants with a normal head ultrasound: prevalence and antecedents

OBJECTIVE

Severe abnormalities of the head ultrasound (HUS) are important predictors of cerebral palsy (CP) and mental retardation, and a normal HUS usually ensures the absence of major impairments. With the increasing survival of extremely low birth weight (ELBW) infants (birth weight <1000 g), the prognostic significance of a normal HUS may differ. This study examined the prevalence of and risk factors for CP and impaired mental development among ELBW infants with a normal HUS.

METHODS

Study infants were ELBW infants who were cared for in Neonatal Research Network centers in the years 1995-1999, had a normal early and late HUS, survived to discharge, and returned for follow-up assessments at 18 to 22 months' corrected age. The outcomes of interest were a score <70 on the Bayley Scales of Infant Development-II Mental Developmental Index (MDI) and CP. Risk factors included maternal demographics; infant characteristics; and interventions or morbidities related to the lung, infection, and nutrition. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). A time-oriented approach was used to select variables for inclusion in logistic models.

RESULTS

Of 1749 infants with a normal early and late HUS (performed at a mean age of 6 and 47 days, respectively), 1473 (84%) returned for follow-up assessment. Infants had a birth weight of 792 +/- 134 g (mean +/- SD) and gestational age of 26 +/- 2 weeks. Rates of CP and MDI <70 were 9.4% and 25.3%, respectively, and 29.2% of infants had either CP or MDI <70. In multivariate analyses, factors associated with CP were male gender (OR: 1.8; 95% CI: 1.2-2.6), multiple birth, (OR: 1.6; 95% CI: 1.1-2.5), decreasing birth weight (OR: 1.3 for each 100-g decrease; 95% CI: 1.1-1.5), pneumothorax (OR: 2.3; 95% CI: 1.2-4.4), and days of conventional ventilation (OR: 1.2 for each additional 10 days; 95% CI: 1.1-1.3). With the exception of pneumothorax, these same factors were associated with MDI <70, in addition to less maternal education (OR: 1.4; 95% CI: 1.0-1.9) and Medicaid or lack of coverage for maternal insurance (OR: 1.7; 95% CI: 1.2-2.4).

CONCLUSIONS

Nearly 30% of ELBW infants with a normal HUS had either CP or a low MDI. Risk factors that are associated with this high rate of adverse outcomes include pneumothorax, prolonged exposure to mechanical ventilation, and educational and economic disadvantage. Improvements in pulmonary care to reduce duration of ventilation and avoid air leaks might improve neurodevelopmental outcome for ELBW infants.

Nutrition for preterm infants after hospital discharge

Preterm infants accrue significant nutrient deficits during hospitalization, and at the time of discharge most VLBW preterm infants have moderate to severe growth failure. Infants with significant morbidities and infants with ELBW have more severe growth failure since they regain birth weight at a later age, and they gain weight more slowly. Catch-up growth accelerates after hospital discharge. The rates of catch-up growth vary according to many factors including birth weight, gestational age, parental size, adequacy of intrauterine growth, neurologic impairment, clinical course, and nutrition. Most catch-up growth occurs within the first 2 to 3 years of life; however, compensatory catch-up growth may continue into adolescence and adulthood. Despite evidence of ongoing catch-up growth, the mean growth measurements of children and adults who were born preterm and with VLBW are lower than their term-born peers. Accelerated rates of catch-up growth are associated with better neurodevelopmental outcomes. Inadequate head circumference growth, in particular, may have long-term prognostic significance for later neurodevelopment in preterm infants. Nutrient-enriched formulas that provide 22 kcal/oz are often prescribed for VLBW preterm infants after hospital discharge. Several studies have reported that preterm infants fed the enriched versus standard term infant formulas have greater rates of catch-up growth during the first year of life, including greater increases in head circumference. The nutrient-enriched formulas appear to be of particular benefit for male infants. There is less information regarding the nutrient needs of breast-fed infants after hospital discharge. However, several studies have demonstrated that preterm infants fed unfortified human milk after discharge have growth rates and bone mass that are lower than formula-fed infants during infancy. The use of fortified human milk, or alternate feedings with a nutrient-enriched formula may be useful for breast-fed infants who have delays in catch-up growth. Additional studies are needed to determine whether enriched feedings might be of particular benefit for preterm infants who are at greater risk for postnatal growth failure, including infants born SGA, or with extremely low birth weights, intrauterine growth restriction, or chronic conditions such as bronchopulmonary dysplasia. The potential effect of nutritional programming on long-term outcomes of preterm infants also requires further investigation.

A new growth chart for preterm babies: Babson and Benda's chart updated with recent data and a new format

BACKGROUND

The Babson and Benda 1976 "fetal-infant growth graph" for preterm infants is commonly used in neonatal intensive care. Its limits include the small sample size which provides low confidence in the extremes of the data, the 26 weeks start and the 500 gram graph increments. The purpose of this study was to develop an updated growth chart beginning at 22 weeks based on a meta-analysis of published reference studies.

METHODS

The literature was searched from 1980 to 2002 for more recent data to complete the pre and post term sections of the chart. Data were selected from population studies with large sample sizes. Comparisons were made between the new chart and the Babson and Benda graph. To validate the growth chart the growth results from the National Institute of Child Health and Human Development Neonatal Research Network (NICHD) were superimposed on the new chart.

RESULTS

The new data produced curves that generally followed patterns similar to the old growth graph. Mean differences between the curves of the two charts reached statistical significance after term. Babson's 10th percentiles fell between the new data percentiles: the 5th to 17th for weight, the 5th and 15th for head circumference, and the 6th and 16th for length. The growth patterns of the NICHD infants deviated away from the curves of the chart in the first weeks after birth. When the infants reached an average weight of 2 kilograms, those with a birthweight in the range of 700 to 1000 grams had achieved greater than the 10th percentile on average for head growth, but remained below the 3rd percentile for weight and length.

CONCLUSION

The updated growth chart allows a comparison of an infant's growth first with the fetus as early as 22 weeks and then with the term infant to 10 weeks. Comparison of the size of the NICHD infants at a weight of 2 kilograms provides evidence that on average preterm infants are growth retarded with respect to weight and length while their head size has caught up to birth percentiles. As with all meta-analyses, the validity of this growth chart is limited by the heterogeneity of the data sources. Further validation is needed to illustrate the growth patterns of preterm infants to older ages.

Catch-up growth of head circumference of very low birth weight, small for gestational age preterm infants and mental development to adulthood

OBJECTIVE

To examine the influence of postnatal energy quotient (EQ, energy intake/kg body weight per day) on head circumference (HC) growth and mental development of very low birth weight (VLBW), small for gestational age (SGA, <10th percentile) preterm infants.

STUDY DESIGN

SGA VLBW preterm infants (n = 46) with primarily symmetric intrauterine growth restriction were compared with 62 appropriate for gestational age (AGA) VLBW preterm infants and 73 term infants from the Bonn Longitudinal study.

RESULTS

Twenty-seven of 46 (59%) of the SGA preterm infants showed complete HC catch-up growth by the age of 12 months, but mostly before 6 months after term (HC catch-up group). These infants had significantly higher mean EQs from day 2 to 10 than the group of 19 infants without HC catch-up (EQ, 95 vs 78). Mean EQs correlated significantly with developmental and intelligence quotients (DQ/IQ) from 18 months to 6 years. As adults, the HC of the HC catch-up group was not significantly different from that of the AGA preterm infants, the term infants, and their parents. The group without HC catch-up had smaller HC as adults.

CONCLUSIONS

Our data suggest that early postnatal high-energy nutrient intake for SGA preterm infants is needed to promote HC catch-up growth and to prevent negative consequences of undernutrition.

Metabolic effects of infection and postnatal steroids

Optimal development of the newborn depends on rapid accretion of substrate in the neonatal period, particularly in the premature infant. Steroids and infection not only induce catabolism, but associated endogenous responses reprioritize crucial substrate to restore homeostasis. The result is a protein/energy deficit and concomitant delay in growth and development. Innovative feeding strategies and novel therapies are needed to reduce the impact of catabolism in this population.

Feeding preterm infants after hospital discharge: growth and development at 18 months of age

We have shown that preterm infants fed a preterm formula grow better than those fed a standard term infant formula after hospital discharge. The purpose of this follow-up study was to determine whether improved early growth was associated with later growth and development. Preterm infants (< or =1750 g birth weight, < or =34 wk gestation) were randomized to be fed either a preterm infant formula (discharge to 6 mo corrected age), or a term formula (discharge to 6 mo), or the preterm (discharge to term) and the term formula (term to 6 mo). Anthropometry was performed at 12 wk and 6, 12, and 18 mo. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 mo. Differences in growth observed at 12 wk were maintained at 18 mo. At 18 mo, boys fed the preterm formula were 1.0 kg heavier, 2 cm longer, and had a 1.0 cm greater occipitofrontal circumference than boys fed the term formula. Boys fed the preterm formula were also 600 g heavier and 2 cm longer than girls fed the preterm formula. However, no differences were noted in MDI or PDI between boys fed the preterm formula and boys fed the term formula or between the boys fed preterm formula and girls fed the preterm formula. Overall, boys had significantly lower MDI than girls (mean difference, 6.0; p < 0.01), primarily reflecting lower scores in boys fed the term formula. Thus, early diet has long-term effects on growth but not development at 18 mo of age. Sex remains an important confounding variable when assessing growth and developmental outcome in these high-risk infants.

Prone and left lateral positioning reduce gastro-oesophageal reflux in preterm infants

AIM

To examine the effect of body position on clinically significant gastro-oesophageal reflux (GOR) in preterm infants.

METHODS

Eighteen preterm infants with clinically significant GOR were studied prospectively using 24 hour lower oesophageal pH monitoring. Infants were nursed in three positions (prone, left, and right lateral) for 8 hours in each position, with the order randomly assigned. Data were analysed using analysis of covariance.

RESULTS

The median (range) reflux index (RI) for the group was 13.8% (5.8-40. 4). There was no significant difference in the mean time spent in each position. RI (mean % (SEM)) was significantly less in prone (6. 3 (1.7)) and left lateral positions (11.0 (2.2)), when compared with the right lateral position (29.4 (3.2)); p<0.001. The mean (SEM) longest episodes (mins) of GOR were reduced by prone and left positions (8.6 (2.2) and 10.0 (2.4), respectively) compared with the right position (26.0 (3.9)); p<0.001. The mean (SE) number of episodes was reduced by prone (15.4 (2.8)) and left (24.6 (3.5)) positions when compared with right (41.6 (4.6)) (p<0.001).

CONCLUSIONS

Prone and left lateral positions significantly reduce the severity of GOR, by reducing the number of episodes and the duration of the longest episodes. Such positioning offers a useful adjunct to the treatment in hospital of preterm infants with gastro-oesophageal reflux.

How often do parenteral nutrition prescriptions for the newborn need to be individualized?

BACKGROUND

Parenteral nutrition is commonly given in the newborn period to premature infants or those with gastrointestinal disorders. Computer-assisted prescribing is widely used, with prescriptions for each patient being varied on a daily basis. It has previously been suggested that 'individualization' of feeds may have little clinical benefit whilst increasing pharmacy workload and costs. However, the scope for use of standard feed solutions as an alternative remains uncertain.

METHODS

To assess the potential for using standardized pre-mixed feeds we prospectively reviewed 148 computer assisted prescriptions for newborn infants in order to establish how often the prescribing clinician adhered to the computer protocol, and the reason for modification when this occurred.

RESULTS

Only one-fifth of feeds were based strictly on the computer recommendation with no, or minimal, modification. However, many of the deviations in the other four-fifths of feed prescriptions reflected a routine use of higher carbohydrate, sodium and phosphate intakes implying that a higher proportion of feeds could be 'standardized' if the computer regimens were modified to reflect current nutritional practices on the unit.

CONCLUSIONS

This study suggests that the introduction of standard PN feeds could considerably reduce the use of computer assisted individualized PN prescriptions on the neonatal unit. The practical implications of such a system for pharmacy and the potential cost benefits deserve further investigation.

Gastric emptying and gastro-oesophageal reflux in preterm infants

Gastro-oesophageal reflux is common in preterm infants, but the role of gastric emptying as a causal factor has not been studied before. Gastric emptying was therefore measured in 19 healthy preterm infants (median gestational age 32 weeks) while concurrently measuring 24 hour lower oesophageal pH, using an antimony pH electrode, positioned manometrically. Real time ultrasonic images of the gastric antrum were obtained, and measurements of antral cross-sectional area (ACSA) were made immediately before a nasogastric feed and then during subsequent gastric emptying until ACSA returned to its pre-feed value. Half emptying time (50% delta ACSA) was calculated as the time taken for the ACSA to fall to half the maximal postprandial increment. Mean (SEM) reflux index for the group was 11.9 (2.0)%; number of reflux episodes per 24 hours: 15.4 (1.7); and number of reflux episodes longer than five minutes 5.5 (0.8). Average half emptying times for an individual infant were: median (range) 46 (18-105) minutes. There was no association between gastric emptying rates and any of the indices of gastro-oesophageal reflux, either during the entire 24 hour period for which the lower oesophageal pH was recorded, or in the postprandial periods after the feeds which were studied ultrasonically. Gastro-oesophageal reflux was also unrelated to feed volume and feed type. Asymptomatic gastro-oesophageal reflux is common in preterm infants, but gastric emptying time is not a determinant of it. Inappropriate relaxation of the lower oesophageal sphincter or abnormal oesophageal motility offer more plausible explanations.