Glucocorticoids and lung development in the fetus and preterm infant

During the final prenatal period of fetal lung development in humans, important maturational processes occur, including the production of surfactant necessary to decrease surface tension at the air-liquid interface of the alveoli. During early gestation, the glucocorticoid receptor is expressed in the fetal lung, and glucocorticoids stimulate the production of surfactant-associated proteins and increase phospholipid synthesis by enhancing the activity of phosphatidylcholine. Other glucocorticoid-induced effects may include stimulation of cell maturation and differentiation, inhibition of DNA synthesis, changes in interstitial tissue components, stimulation of antioxidant enzymes, and regulation of pulmonary fluid metabolism. Recently, it was suggested that glucocorticoids are also important in postnatal pulmonary development, and may be related to the development of neonatal lung disease in preterm infants. Surfactant deficiency that can be prevented by antenatal corticosteroid treatment causes infant respiratory distress syndrome and requires mechanical ventilation. Ventilation by itself or in combination with high levels of oxygen, fluid overload, pulmonary infections, sepsis, and air leak syndrome causes an acute pulmonary inflammatory reaction that may result in chronic lung disease or bronchopulmonary dysplasia. Glucocorticoids are effective in the treatment of chronic lung disease of prematurity and regulate the inflammatory response by the interaction with transcription factors such as nuclear factor kappaB and activated protein 1. Indeed, inflammatory cells and the levels of chemokines and cytokines in bronchoalveolar fluid decrease after dexamethasone treatment. However, treatment of fetuses and preterm infants with repeated and/or high doses of corticosteroids may have considerable long-term side effects on somatic, brain, and lung growth. The difficult balance between short-term gain and the possible long-term side effects of glucocorticoids in preterms remains a difficult issue.

The intestinal bacterial colonisation in preterm infants: a review of the literature

The aim of this study is to review the normal development of the intestinal microflora of preterm infants and the factors influencing its development. Preterm infants have an increased intestinal permeability, which may lead to bacterial translocation to systemic organs and tissues. In combination with immaturity of the immune system the risk to systemic infections might be increased. Especially potential pathogenic bacteria are able to translocate. The intestinal microflora of breast-fed term infants, dominated by bifidobacteria and lactobacilli, is thought to suppress the growth of potentially pathogenic bacteria. Many attemps have been made to stimulate the presence of bifidobacteria and lactobacilli with changes in the diet and ingredients-like prebiotics and probiotics. After selection, six studies were included reviewing the intestinal bacterial colonisation of preterm infants. In general, these studies show that the intestinal bacterial colonisation with beneficial bacteria is delayed in preterm infants. The number of potentially pathogenic bacteria is high. Antibiotics influence the intestinal colonisation. Many preterm infants receive prophylactic antibiotics at birth. As antibiotics delay the normal intestinal colonisation, caution should be given to the treatment with broadspectrum antibiotics in preterm infants at birth and every attempt has to be made to restrict the period of treatment.

MR patterns of hypoxic-ischemic brain damage after prenatal, perinatal or postnatal asphyxia

The relationship between MR patterns of brain damage and type or timing of perinatal hypoxia-ischemia was studied. MR images of 104 children with evidence of bilateral posthypoxic-ischemic brain damage and neonatal records were reviewed. Three different MR patterns were found. Periventricular leukomalacia occurred in 73 children, in 82% after a history of subacute or chronic hypoxia-ischemia, in 71% after preterm birth. Predominant lesions of basal ganglia and thalamus occurred in 21 children, in 95% preceded by acute profound asphyxia, in 85% after term birth. Multicystic encephalopathy occurred in 10 infants, in 70% preceded by mild signs of hypoxia-ischemia, followed by an unexpectedly severe encephalopathy, in 60% after term birth. Statistical analysis showed that the patterns of injury were primarily related to the type of hypoxia-ischemia. We conclude that the type of hypoxia-ischemia, rather than the postconceptional age at occurrence determines the pattern of brain injury.

Attention problems of very preterm children compared with age-matched term controls at school-age

OBJECTIVES

To clarify the severity, specificity, and neurocognitive underpinnings of attention problems in very preterm children.

STUDY DESIGN

A sample of 66 preterm (<32 weeks gestation), mean (SD) age 7.5 (0.4) years, and 66 age-matched term controls participated. Symptoms of inattention were assessed using parent and teacher-rated questionnaires, and neurocognitive measures included speed and consistency in speed of information processing, lapses of attention (tau), alerting, orienting, and executive attention, as well as verbal and visuospatial working memory. Group differences were investigated using ANOVA, and Sobel tests were used to clarify the mediating role of neurocognitive impairments on attention problems.

RESULTS

There was a large decrease in visuospatial working memory abilities (P < .001, d = .87), and medium increases in tau (P = .002, d = 0.55) as well as parent and teacher ratings of inattention (range d = 0.40-0.56) in very preterm children compared with term peers. Tau and visuospatial working memory were significant predictors of parent (R(2) = .161, P < .001 and R(2) = .071, P = .001; respectively) and teacher (R(2) = .152, P < .001 and R(2) = .064, P = .002; respectively) ratings of inattention, and completely explained the effects of very preterm birth on attention problems.

CONCLUSIONS

Increased lapses of attention and poorer visuospatial working memory fully account for the attention problems in very premature children at school-age.

Neutral and acidic oligosaccharides in preterm infants: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Serious infectious morbidity is high in preterm infants. Enteral supplementation of prebiotics may reduce the incidence of serious infections, especially infections related to the gastrointestinal tract.

OBJECTIVE

The objective was to determine the effect of enteral supplementation of a prebiotic mixture consisting of neutral oligosaccharides ((SC)GOS/(LC)FOS) and acidic oligosaccharides (AOS) on serious infectious morbidity in preterm infants.

DESIGN

In a randomized controlled trial, preterm infants (gestational age <32 wk and/or birth weight <1500 g) received enteral supplementation of 80% (SC)GOS/(LC)FOS and 20% AOS (1.5 g . kg(-1) . d(-1)) or placebo (maltodextrin) between days 3 and 30 of life. Serious infectious morbidity was defined as a culture positive for sepsis, meningitis, pyelonephritis, or pneumonia. The analysis was performed by intention-to-treat and per-protocol, defined as > or =50% supplementation dose during the study period.

RESULTS

In total, 113 preterm infants were included. Baseline and nutritional characteristics were not different between groups. In the intention-to-treat analysis, the incidence of > or =1 serious infection, > or =1 serious endogenous infection, or > or =2 serious infectious episodes was not significantly different in the (SC)GOS/(LC)FOS/AOS-supplemented and placebo groups. In the per-protocol analysis, there was a trend toward a lower incidence of > or =1 serious endogenous infection and > or =2 serious infectious episodes in the (SC)GOS/(LC)FOS/AOS-supplemented group than in the placebo group (P = 0.09 and P = 0.07, respectively).

CONCLUSIONS

Enteral supplementation of (SC)GOS/(LC)FOS/AOS does not significantly reduce the risk of serious infectious morbidity in preterm infants. However, there was a trend toward a lower incidence of serious infectious morbidity, especially for infections with endogenous bacteria. This finding suggests a possible beneficial effect that should be evaluated in a larger study. This trial was registered at isrctn.org as ISRCTN16211826.

Predictive value of neonatal MRI with respect to late MRI findings and clinical outcome. A study in infants with periventricular densities on neonatal ultrasound

PURPOSE

The aim of this study was to correlate hypoxic-ischemic white matter damage on neonatal MRI with MRI appearance and neurological outcome at the age of 1 1/2 years.

PATIENTS AND METHODS

A sequential cohort of infants with periventricular densities on neonatal ultrasound was studied with neonatal MRI. Images of 46 infants with a mean gestational age of 31 weeks were obtained at a mean age of 20 days after birth and at 1 1/2 years. To establish agreement between the neonatal and follow-up MRI (general, motor, and visual scores), the weighted Cohen's kappa test was used. To establish the predictive power of neonatal MRI with respect to the neurologic indices at the age of 1 1/2 years, the sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

There was a moderately good to good agreement between the general, motor, and visual neonatal and follow-up MRI scores: weighted kappa = 0.59 (95% CI: 0.44 - 0.74), 0.82 (95% CI: 0.72 - 0.93), and 0.70 (95% CI: 0.56 - 0.84), respectively. Neonatal MRI scores provided a good prediction of the three neurological outcome measures (developmental delay, cerebral palsy, and cerebral visual impairment): sensitivity, specificity, and predictive values were high, with little difference between the three MRI scores. The 32 patients with (nearly) normal neonatal MRI scores were neurologically (nearly) normal at 1 1/2 years on all three outcome measures, whereas 8 patients with seriously abnormal neonatal MRI scores were neurologically abnormal at 1 1/2 years on all three outcome measures.

CONCLUSION

Neonatal MRI is able to predict the precise localization and size of perinatal leukomalacia on follow-up MRI and provides a good prediction of neurological outcome at 1 1/2 years.

Short-term growth and substrate use in very-low-birth-weight infants fed formulas with different energy contents

BACKGROUND

Currently available preterm formulas with energy contents of 3350 kJ (800 kcal)/L promote weight and length gain at rates at or above intrauterine growth rates but disproportionately increase total body fat.

OBJECTIVE

The objective of this study was to determine whether fat accretion in formula-fed, very-low-birth-weight (VLBW) infants could be decreased and net protein gain maintained by reducing energy intakes from 502 kJ (80 kcal)*kg(-)(1)*d(-)(1) [normal-energy (NE) formula] to 419 kJ (100 kcal)*kg(-)(1)*d(-)(1) [low-energy (LE) formula] while providing similar protein intakes (3.3 g*kg(-)(1)*d(-)(1)).

DESIGN

The study was a randomized, controlled trial enrolling 20 appropriate-for-gestational-age (AGA) and 16 small-for-gestational-age (SGA) VLBW infants (mean birth weight: 1.1 kg; mean gestational age: 31 wk); energy expenditure and nutrient balance were measured at 4 wk of age and anthropometric measurements were made when infants weighed 2 kg.

RESULTS

The percentage of fat in newly formed tissue was significantly lower in AGA infants fed the LE formula (n = 9) than in those fed the NE formula (n = 10) (9% compared with 23%; analysis of variance, P = 0.001). Energy expenditure was higher in AGA infants fed the NE formula than in those fed the LE formula. Skinfold thickness was markedly lower in AGA infants fed the LE formula than in those fed the NE formula, resulting in a lower estimated percentage body fat (8.0 +/- 1.9% and 10.8 +/- 3.5%, respectively; P < 0.05). Three of 6 SGA infants fed the LE formula were excluded during the study because of poor weight gain.

CONCLUSIONS

Body composition can easily be altered by changing the energy intakes of formula-fed VLBW infants. Energy intakes in these infants should be >419 kJ (100 kcal)*kg(-)(1)*d(-)(1).

Magnetic resonance imaging of the brain in premature infants during the neonatal period. Normal phenomena and reflection of mild ultrasound abnormalities

An MRI study was performed in 34 preterm infants who were clinically and neurologically normal and whose cranial ultrasound revealed no or only mild abnormalities. The postconceptional age at MRI varied between 30.6 and 37 weeks. The purpose of the study was to evaluate the significance of periventricular changes in signal intensity on MRI, comparing MRI with ultrasound. T1-weighted and T2-weighted images were assessed for changes in signal intensity of the periventricular white matter relative to the remainder of the cerebral hemispheric white matter. Cerebral MRIs of 13 postterm infants were additionally investigated. In all preterm infants small localized areas of high signal intensity on T1-weighted images and low signal intensity on T2-weighted images were seen adjacent to the frontal horns of the lateral ventricles. They faded with increasing age and were no longer seen one month after term in the group of postterm infants. The areas were considered normal before term age and probably represent remnants of the germinal matrix. Periventricular echodensities corresponded with a zone of changed signal intensity within the periventricular white matter on MRI. MRI signal change correlated with the presence and location of echodensities; the MRI signal changes slowly faded away after the echodensities disappeared.

Arginine and mixed amino acids increase protein accretion in the growth-restricted and normal ovine fetus by different mechanisms

Protein metabolism may be perturbed in intrauterine growth restriction (IUGR). Arginine is indispensable for growth and nitrogen balance in young mammals. Fetuses with IUGR therefore may benefit from arginine supplementation. The purpose of this study was to determine 1) the effects of IUGR on protein metabolism in the ovine fetus and 2) the effects of arginine or mixed amino acid (AA) infusion on protein metabolism in these fetuses. Pregnant ewes and their fetuses were catheterized at 110 d gestation and randomly assigned to control or IUGR groups. IUGR was induced by repetitive placental embolization. Parameters of fetal protein metabolism were determined from [ring-(2)H(5)]phenylalanine kinetics at baseline and in response to a 4-h infusion of either arginine or an isonitrogenous AA mixture. There were no differences in protein metabolism between control and IUGR groups either at baseline or in response to arginine or AA treatment. Both arginine and AA infusion increased fetal protein accretion in both groups. Arginine did this by decreasing protein turnover, synthesis, and breakdown. AAs increased protein turnover and synthesis while decreasing protein breakdown. AA infusion resulted in a significantly higher increase in protein accretion than arginine infusion. Thus, in the ovine fetus, placental embolization has no clear effect on protein metabolism. Arginine and AAs both stimulate protein accretion but do so in distinctly different ways. Mixed AA infusion has a greater effect on protein accretion than arginine alone and therefore may be a better strategy for stimulating fetal growth.

Relative kinetics of phenylalanine and leucine in low birth weight infants during nutrient administration

The effect of the route of nutrient administration on the relative rates of leucine and phenylalanine kinetics was examined in 30 low birth weight (LBW) infants using L-[1-(13)C]leucine, L-[2H5]phenylalanine, and L-[2H2]tyrosine tracers. The infants received special premature formula (PF, n = 10, 117 +/- 8 kcal.kg-1.d-1 and 3.2 +/- 0.2 g protein.kg-1.d-1) or fortified human milk (HM, n = 10, 106 +/- 6 kcal.kg-1.d-1 and 3.0 +/- 0.2 g protein.kg-1.d-1), or parenteral nutrition (PN, n = 10, 80 +/- 25 kcal.kg-1.d-1 and 1.8 +/- 0.3 g protein.kg-1.d-1). The rate of appearance (Ra) of leucine (RaLeu), was significantly higher in group PF as compared with groups HM and PN (434 +/- 51 versus 377 +/- 33 and 359 +/- 50 mumol.kg-1.h-1, p < 0.05). The Ra of phenylalanine (RaPhe) was lower in group HM as compared with group PF (94 +/- 18 versus 115 +/- 16, p < 0.05), RaPhe in group PN (108 +/- 24 mumol.kg-1.h-1) was in between group PF and HM. The relative rate of RaPhe and RaLeu expressed as RaPhe/ RaLeu ratio was lower in all groups than that expected from reported whole body protein composition and from that reported in adults. The ratio of phenylalanine hydroxylation to leucine decarboxylation was 0.202 in group PF, 0.212 in group HM, and 0.161 in group PN, suggesting a higher rate of decarboxylation of leucine relative to hydroxylation of phenylalanine. We conclude that: 1) the higher RaLeu compared with the RaPhe may be the result of either a higher turnover of a body protein enriched in leucine or the consequence of higher leucine intake in infant nutrition and 2) whole body protein kinetics calculated from a single amino acid tracer do not adequately represent whole body protein metabolism.

Comparison of short term indirect calorimetry and doubly labeled water method for the assessment of energy expenditure in preterm infants

The accuracy of 8-hour indirect calorimetry (IDC) as an estimate of energy expenditure was investigated in 8 healthy preterm infants (birth weight 1,270 +/- 193 g, gestational age 32 +/- 3 weeks, mean +/- SD) in comparison with an analysis over 5 days using the doubly-labeled water (2H2(18)O) method (DLW). The infants that were fed continuously by nasogastric drip with 120 kcal/kg/day of special infant formula were measured twice under thermoneutral conditions in a closed system indirect calorimeter during 8 h with a 4-day interval; simultaneously isotope decay was measured by isotope ratio mass spectrometry in urine samples collected daily during 5 days from 6 h after an oral dose of 2H2(18)O on the first day of IDC, all during the 4th postnatal week. The mean differences between carbon dioxide production rate (rCO2) measured either by single 8-hour IDC or by duplicate 8-hour IDC and the 5-day DLW method, using the two-point analysis or the multipoint analysis were not significantly different from zero. The rCO2 calculated from the DLW method using the two-point analysis differed -1.4 +/- 1.7% from that measured by the multipoint analysis. The mean differences between the metabolic rate estimated from 8 h of IDC and from the 5-day DLW method based on a measured RQ of 0.90 was -6.7 +/- 6.2% and based on the RQ of the feeding -4.5 +/- 6.0%. These differences were not significantly different from zero. We conclude that IDC over 8 h and two-point DLW measurement over 5 days, both methods that can be applied with relative ease in practice, offer an adequate average estimate of energy expenditure in continuously fed preterm infants under thermoneutral conditions.

Development of Nationwide Recommendations to Support Prenatal Counseling in Extreme Prematurity

OBJECTIVES

To develop a nationwide, evidence-based framework to support prenatal counseling in extreme prematurity, focusing on organization, decision-making, content, and style aspects.

METHODS

A nationwide multicenter RAND-modified Delphi method study was performed between November 2016 and December 2017 in the Netherlands. Firstly, recommendations were extracted from literature and previous studies. Secondly, an expert panel (n = 21) with experienced parents, obstetricians, and neonatologists rated the recommendations on importance for inclusion in the framework. Thirdly, ratings were discussed in a consensus meeting. The final set of recommendations was approved and transformed into a framework.

RESULTS

A total of 101 recommendations on organization, decision-making, content, and style were included in the framework, including tools to support personalization. The most important recommendations regarding organization were to have both parents involved in the counseling with both the neonatologist and obstetrician. The shared decision-making model was recommended for deciding between active support and comfort care. Main recommendations regarding content of conversation were explanation of treatment options, information on survival, risk of permanent consequences, impossibility to predict an individual course, possibility for multiple future decision moments, and a discussion on parental values and standards. It was considered important to avoid jargon, check understanding, and provide a summary. The expert panel, patient organization, and national professional associations (gynecology and pediatrics) approved the framework.

CONCLUSIONS

A nationwide, evidence-based framework for prenatal counseling in extreme prematurity was developed. It contains recommendations and tools for personalization in the domains of organization, decision-making, content, and style of prenatal counseling.

The effect of neutral and acidic oligosaccharides on stool viscosity, stool frequency and stool pH in preterm infants

AIM

To determine the effect of neutral oligosaccharides [small-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides (scGOS/lcFOS)] in combination with acidic oligosaccharides (pAOS) on stool viscosity, stool frequency and stool pH in preterm infants.

METHODS

In this explorative RCT, preterm infants with gestational age <32 weeks and/or birth weight <1500 g received enteral supplementation with scGOS/lcFOS/pAOS or placebo (maltodextrin) between days 3 and 30 of life. Stool samples were collected at day 30 after birth.

RESULTS

In total, 113 infants were included. Baseline and nutritional characteristics were not different between both groups. Stool viscosity at day 30 was lower in the prebiotics group (16.8N) (3.9-67.8) compared with the placebo group (26.3N) (1.3-148.0) (p = 0.03; 95% CI -0.80 to 0.03). There was a trend towards higher stool frequency in the prebiotics group (3.1 ± 0.8) compared with the placebo group (2.8 ± 0.7) (p = 0.15; 95% CI -0.08 to 0.52). Stool pH at day 30 was lower in the in the prebiotics group (5.9 ± 0.6) compared with the placebo group (6.2 ± 0.3) (p = 0.009; 95% CI 0.08 to 0.53).

CONCLUSIONS

Enteral supplementation of a prebiotic mixture consisting of neutral (scGOS/lcFOS) and acidic oligosaccharides (pAOS) decreases stool viscosity and stool pH with a trend towards increased stool frequency in preterm infants. The inclusion of pAOS in a formula containing a mixture of scGOS/lcFOS does not add specific advantages to the formula in terms of stool viscosity, frequency, pH as well as feeding tolerance.

Fetal growth and the function of the adrenal cortex in preterm infants

Small for gestational age preterm infants have a higher risk of neonatal morbidity compared to appropriate for gestational age preterm infants. A diminished adrenal response to stress may be involved in the higher postnatal morbidity. The adrenal cortex response in relation to fetal growth was studied by ACTH stimulation tests in 43 preterm infants (born < or = 32 wk). The cortisol and 17-hydroxyprogesterone (17-OHP) responses to 1 microg/kg ACTH were analyzed in relation to birth weight SD scores (BW-SDS) corrected for gestational age, gender, and parity. BW-SDS was significantly associated with the cortisol and 17-OHP response. Infants with the lowest BW-SDS had the lowest cortisol levels after stimulation. No effect of size at birth was found on the ratio between cortisol and 17-OHP. In addition, basal cortisone levels in a single blood sample were higher in infants with the lowest BW-SDS than in infants with higher BW-SDS, but the ratio between cortisol and cortisone was comparable in the two groups. We conclude that the response of cortisol and 17-OHP to ACTH stimulation in preterm infants is related to fetal growth. The lack of influence of fetal growth on the ratio between cortisol and 17-OHP after ACTH stimulation suggests that the activities of 21- and 11 beta-hydroxylase are not affected. The lower adrenal response to stimulation may be important in neonatal morbidity and possibly the development of disease in later life in growth-restricted preterm infants.

Predictive value of neonatal MRI as compared to ultrasound in premature infants with mild periventricular white matter changes

A follow-up study was performed in 42 premature infants in whom serial neonatal ultrasound and a single neonatal MRI of the brain was normal, or showed mild periventricular white matter changes. The aim of the study was to evaluate the clinical significance of periventricular signal intensity changes on MRI and to compare the predictive value of neonatal MRI with that of ultrasound. The infants underwent repeated standardised motor assessments and developmental tests. MRI was repeated at the corrected age of 12 months. Pronounced periventricular signal intensity changes on neonatal MRI and periventricular echodensities (flaring) on ultrasound were associated with a high incidence of transient motor problems during infancy. The degree of echogenicity carried the highest predictive value, as compared to duration of flaring on ultrasound and degree of periventricular signal intensity change on MRI. It is concluded that signal intensity changes on neonatal MRI represent the same ischaemic change of the periventricular white matter as flaring on ultrasound and that routine neonatal MRI screening is not warranted in premature infants without clinical evidence of neurological problems and with normal or mildly abnormal ultrasound scans. Recording of the degree of echogenicity should become a routine procedure in neonatal cerebral ultrasonography.

Quantitation of oxidation of medium-chain triglycerides in preterm infants

Medium-chain triglycerides, with a chain length of eight and 10 carbon atoms, form up to 50% of the total fat content in some preterm infant formulas. In 20 small preterm infants (birthwt: 1153 +/- 227 g; mean +/- SD) fed a special formula containing 40% MCT, a primed constant oral infusion study of 1-13C-potassium octanoate was conducted to quantify the oxidation of MCT. A plateau in 13C enrichment in breath CO2 was reached in all patients within 1-3 h. Simultaneously, substrate utilization was measured using a closed system indirect calorimeter. No significant difference was found between appropriate for gestational age (n = 8) and small for gestational age (n = 12) infants in the percentage of the administered tracer that was oxidized (44.9 +/- 9.1% versus 48.5 +/- 11.0%). In all patients, the recovery was calculated to be 47.1 +/- 10.2%, which is less than previously estimated and corresponds to a mean MCT oxidation of 1.26 +/- 0.27 g/kg/d. With indirect calorimetry, a total fat oxidation of 1.42 +/- 0.84 g/kg/d in appropriate for gestational age and 2.00 +/- 0.85 g/kg/d in small for gestational age infants was found, indicating that MCT accounted for around 85% of the total fat oxidation in appropriate for gestational age versus 65% in small for gestational age infants.

Attention deficit hyperactivity disorder and autism spectrum disorder symptoms in school-age children born very preterm

BACKGROUND

Very preterm (VP) children face a broad range of neurodevelopmental sequelae, including behavioral problems.

AIM

To investigate prevalence, pervasiveness and co-occurrence of symptoms of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in school-age children born very preterm.

METHODS

Using questionnaire and diagnostic interview data, parent and teacher reported symptoms of ADHD and ASD of 57 VP-children (mean age = 9.2 years) were compared with 57 gender and age matched full-term children using t-tests. Intra-class correlation coefficients quantified parent-teacher agreement. Correlation analysis investigated co-occurrence of ADHD/ASD symptoms. ADHD/ASD measures were aggregated using principal component analysis. Regression analyses investigated the contribution of perinatal risk factors, sex and SES to ADHD/ASD symptoms.

RESULTS

VP-children showed higher levels of parent and teacher reported attention problems, social impairment and compromised communication skills. Fair to strong agreement was found between parent and teacher reported ADHD and ASD symptoms, indicating pervasiveness of observed difficulties. Co-occurrence of ADHD and ASD symptoms in VP-children was found. Lower gestational age was associated with higher ADHD and ASD symptom levels, male sex with higher ADHD symptom levels and lower SES with higher ASD symptom levels.

CONCLUSION

School-age VP-children show higher levels of ADHD and ASD symptoms, and attention, socialization and communication difficulties in particular. Routinely screening for these problems is recommended in follow-up care.

Pharmacokinetics of Meropenem in Preterm Neonates

The objective of this study was to evaluate and compare the pharmacokinetics of meropenem in premature neonates, both after the first dose and during steady state at day 5, after a 1-minute intravenous administration to evaluate the possibility of twice-daily administration. Seven premature neonates received 15 mg/kg meropenem twice daily on clinical grounds as a 1-minute infusion. After the first dose and during steady state at day 5, serum levels of meropenem were measured for 12 hours after intravenous administration. Meropenem pharmacokinetics at the first dose were studied in seven children (mean birth weight 925 g, mean postnatal age 21 days). Serum concentration-time curves could be described with a one-compartment model. Mean total body clearance was 0.157 L/kg per hour, volume of distribution was 0.74 L/kg, and half-life was 3.4 hours. At day 5 at steady state, pharmacokinetic properties did not differ significantly. No side effects were noted. A 1-minute intravenous administration is feasible. Pharmacokinetic properties are comparable at day 5 compared with the first dose, and half-life is such that twice-daily administration of 15 mg/kg produces adequate serum concentrations.

Accuracy of oscillometric blood pressure measurement in critically ill neonates with reference to the arterial pressure wave shape

OBJECTIVE

To perform further evaluation of the oscillometric device for neonatal arterial blood pressure (ABP) measurement, using a catheter-manometer system (CMS) for accurate intraarterial measurement. We aimed to describe the influence of the radial artery wave shape on oscillometric ABP determination, as pressure wave-shape influences the relationships between systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and mean arterial pressure (MAP) in the wave. These relationships are part of the algorithms contributing to the final ABP determination in the oscillometric device.

DESIGN

Intra-patient comparison of two blood pressure measurement systems.

SETTING

Neonatal intensive care unit.

PATIENTS

In 51 critically ill newborn infants, ABP was determined oscillometrically in the brachial artery and, simultaneously, invasively in the radial artery using a high-fidelity CMS. Clinical data of the infants were: gestational age: 29 (25-41) weeks; birthweight: 1200 (500-3675) g, postnatal age: 6 (2-46) h.

METHODS

Statistical analysis was performed with the paired Student's t-test. Multiple regression analysis was used to determine the influence of birthweight and height of the blood pressure on the results.

MEASUREMENTS AND MAIN RESULTS

In 51 infants, 255 paired values of SAP, DAP and MAP were recorded. In all recordings, we determined the relationship between SAP, DAP and MAP, using the equation: MAP = alpha%(SAP - DAP) + DAP. For SAP, DAP, MAP and alpha, we computed mean differences (bias) and the limits of agreement (precision). Biases for SAP, DAP, MAP and alpha were significantly different from zero (P < 0.001) and the limits of agreement for SAP, DAP and MAP were wide: 18.8 mmHg, 17.2 mmHg and 15.2 mmHg respectively. The relationship between invasive and noninvasive values is only partly (7-19%) influenced by the height of the blood pressure; low values of SAP, DAP and MAP tend to give overestimated oscillometric values. In the relationship between SAP, DAP and MAP, alpha was found to be 47% invasively (as generally found in the radial artery in newborns) and 34% noninvasively (as generally found in the brachial/radial artery in adults).

CONCLUSIONS

Inaccuracy of the oscillometric device may be partly explained by the incorporation of an inappropriately fixed algorithm for final ABP determination in newborns. Care should be taken when interpreting the oscillometrically derived values in critically ill newborn infants.

Sensory modulation in preterm children: Theoretical perspective and systematic review

BACKGROUND

Neurodevelopmental sequelae in preterm born children are generally considered to result from cerebral white matter damage and noxious effects of environmental factors in the neonatal intensive care unit (NICU). Cerebral white matter damage is associated with sensory processing problems in terms of registration, integration and modulation. However, research into sensory processing problems and, in particular, sensory modulation problems, is scarce in preterm children.

AIM

This review aims to integrate available evidence on sensory modulation problems in preterm infants and children (<37 weeks of gestation) and their association with neurocognitive and behavioral problems.

METHOD

Relevant studies were extracted from PubMed, EMBASE.com and PsycINFO following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Selection criteria included assessment of sensory modulation in preterm born children (<37 weeks of gestation) or with prematurity as a risk factor.

RESULTS

Eighteen studies were included. Results of this review support the presence of sensory modulation problems in preterm children. Although prematurity may distort various aspects of sensory modulation, the nature and severity of sensory modulation problems differ widely between studies.

CONCLUSIONS

Sensory modulation problems may play a key role in understanding neurocognitive and behavioral sequelae in preterm children. Some support is found for a dose-response relationship between both white matter brain injury and length of NICU stay and sensory modulation problems.

Effects of high carnitine supplementation on substrate utilization in low-birth-weight infants receiving total parenteral nutrition

Parenterally fed preterm neonates are known to be at risk for carnitine deficiency. We studied substrate utilization in low-birth-weight infants receiving total parenteral nutrition (TPN) with (A) and without (B) supplementation of 48 mg carnitine.kg-1.d-1 on days 4-7 (birth weights 1334 +/- 282 vs 1318 +/- 248 g, gestational age 32 +/- 2 vs 32 +/- 2 wk, A vs B, respectively). TPN consisted of 11 g glucose.kg-1.d-1 and 2.4 g.kg-1.d-1 of both protein and fat. Plasma carnitine concentrations at day 7 were for free carnitine 11.8 +/- 5.0 vs 164 +/- 56 mumol/L and for acyl carnitine 3.8 +/- 2.0 vs 33.9 +/- 15.4 mumol/L, respectively. Indirect calorimetry at day 7 showed a higher fat oxidation (0.21, -0.31 to +0.60 vs 1.18, 0.70 to 1.95 g. kg-1.d-1, respectively, P less than 0.02, median and interquartile range) in group B and a higher protein oxidation (0.37, 0.30-0.43 vs 0.63, 0.53-0.88 g.kg-1.d-1, P less than 0.001). The time to regain birth weight was also higher in group B (7, 5.5-9 vs 9, 7-14 d, P less than 0.05). Carnitine supplementation and calorie intake were the best explanatory variables for metabolic rate (R2 = 0.45, P less than 0.002). We conclude that carnitine supplementation of TPN in this dosage does not seem advisable.

Timing of nutritional interventions in very-low-birth-weight infants: optimal neurodevelopment compared with the onset of the metabolic syndrome

Recent nutritional research in very-low-birth-weight (VLBW) infants is focused on the prevention of protein malnutrition during the first postnatal weeks. At this early age, nutritional protein fortification depends on amino acid infusion via a central vein because of the immature gastrointestinal tract. In 2010 new guidelines on nutrition were proposed by the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition nutrition committee. In particular, the relative increase in the protein fraction in the nutrition of these infants aims to prevent early postnatal weight loss, to prevent morbidity, and to stimulate neurodevelopment. On the other hand, an increasing number of follow-up studies in VLBW infants indicate that, in particular, those infants who show rapid growth after preterm birth are at risk of metabolic consequences and cardiovascular disease later in life. In this review, we describe the quest to develop a customized diet that offers optimal nutrition at several time points of growth and development during the first year of life. This diet should prevent early malnutrition, enhance neurodevelopment, and limit the increase in total body fat during the first 6 mo. We question whether one type of early diet suffices for normal neurodevelopment with a normal body composition in later life or whether we need several types of diet at various stages of development.

Design of a randomised controlled trial on immune effects of acidic and neutral oligosaccharides in the nutrition of preterm infants: carrot study

Background

Prevention of serious infections in preterm infants is a challenge, since prematurity and low birth weight often requires many interventions and high utility of devices. Furthermore, the possibility to administer enteral nutrition is limited due to immaturity of the gastrointestinal tract in the presence of a developing immune system. In combination with delayed intestinal bacterial colonisation compared with term infants, this may increase the risk for serious infections. Acidic and neutral oligosaccharides play an important role in the development of the immune system, intestinal bacterial colonisation and functional integrity of the gut. This trial aims to determine the effect of enteral supplementation of acidic and neutral oligosaccharides on infectious morbidity (primary outcome), immune response to immunizations, feeding tolerance and short-term and long-term outcome in preterm infants. In addition, an attempt is made to elucidate the role of acidic and neutral oligosaccharides in postnatal modulation of the immune response and postnatal adaptation of the gut.

Methods/Design

In a double-blind placebo controlled randomised trial, 120 preterm infants (gestational age <32 weeks and/or birth weight <1500 gram) are randomly allocated to receive enteral acidic and neutral oligosaccharides supplementation (20%/80%) or placebo supplementation (maltodextrin) between day 3 and 30 of life. Primary outcome is infectious morbidity (defined as the incidence of serious infections). The role of acidic and neutral oligosaccharides in modulation of the immune response is investigated by determining the immune response to DTaP-IPV-Hib(-HBV)+PCV7 immunizations, plasma cytokine concentrations, faecal Calprotectin and IL-8. The effect of enteral acidic and neutral oligosaccharides supplementation on postnatal adaptation of the gut is investigated by measuring feeding tolerance, intestinal permeability, intestinal viscosity, and determining intestinal microflora. Furthermore, short-term and long-term outcome are evaluated.

Discussion

Especially preterm infants, who are at increased risk for serious infections, may benefit from supplementation of prebiotics. Most studies with prebiotics only focus on the colonisation of the intestinal microflora. However, the pathways how prebiotics may influence the immune system are not yet fully understood. Studying the immune modulatory effects is complex because of the multicausal risk of infections in preterm infants. The combination of neutral oligosaccharides with acidic oligosaccharides may have an increased beneficial effect on the immune system. Increased insight in the effects of prebiotics on the developing immune system may help to decrease the (infectious) morbidity and mortality in preterm infants.

Trial registration

Current Controlled Trials ISRCTN16211826.