Impact of perinatal corticosteroids on neuromotor development and outcome: review of the literature and new meta-analysis

Comparison of neonatal outcomes between multiples and singletons among very low birth weight infants: the Korean Neonatal Network cohort study

OBJECTIVE

To compare neonatal outcomes between multiples and singletons among very low birth weight infants, this was a prospective cohort study that was conducted by collecting data registered in the Korean Neonatal Network database.

METHODS

From January 2013 to December 2016, there were 8265 infants in the Korean Neonatal Network database, and 2958 of them were from multiples. Among them, 2636 infants were twins, 308 infants were triplets, and 14 infants were quadruplets. Maternal and neonatal variables including and mortality major morbidity were compared. Finally, the predicted rates of major morbidity between singletons and multiples.

RESULTS

Multiples had higher gestational age, birth weight, Apgar score at 5 min, rates of cesarean section and artificial reproductive technology but lower maternal hypertension, oligohydramnios, chorioamnionitis rates and Clinical Risk Index for Babies scores II without base excess than the singletons. In univariate analysis, multiples had a lower incidence of respiratory distress syndrome, bronchopulmonary dysplasia, and sepsis. The mortality rate was not significantly different for overall gestational ages except for those born at ≤26 weeks of gestation. In multivariate logistic analysis, the incidences of intraventricular hemorrhage (grade ≥3), and retinopathy of prematurity requiring treatment were significantly higher than the singletons.

CONCLUSIONS

Mortality was not significantly different between multiples and singletons according to overall gestational age, except for multiples born at ≤26 weeks. A significant higher risk of intraventricular hemorrhage and retinopathy of prematurity requiring treatment was found in multiples. A new strategy to improve the mortality of immature multiples born at ≤26 weeks of gestation should be developed.

Infantile Cocktail of Erythropoietin and Melatonin Restores Gait in Adult Rats with Preterm Brain Injury

Cerebral palsy (CP) is the most common cause of physical disability for children worldwide. Many infants and toddlers are not diagnosed with CP until they fail to achieve obvious motor milestones. Currently, there are no effective pharmacologic interventions available for infants and toddlers to substantially improve their trajectory of neurodevelopment. Because children with CP from preterm birth also exhibit a sustained immune system hyper-reactivity, we hypothesized that neuro-immunomodulation with a regimen of repurposed endogenous neurorestorative medications, erythropoietin (EPO) and melatonin (MLT), could improve this trajectory. Thus, we administered EPO + MLT to rats with CP during human infant-toddler equivalency to determine whether we could influence gait patterns in mature animals. After a prenatal injury on embryonic day 18 (E18) that mimics chorioamnionitis at ∼25 weeks human gestation, rat pups were born and raised with their dam. Beginning on postnatal day 15 (P15), equivalent to human infant ∼1 year, rats were randomized to receive either a regimen of EPO + MLT or vehicle (sterile saline) through P20. Gait was assessed in young adult rats at P30 using computerized digital gait analyses including videography on a treadmill. Results indicate that gait metrics of young adult rats treated with an infantile cocktail of EPO + MLT were restored compared to vehicle-treated rats (p < 0.05) and similar to sham controls. These results provide reassuring evidence that pharmacological interventions may be beneficial to infants and toddlers who are diagnosed with CP well after the traditional neonatal window of intervention.

Hydrocortisone to treat early bronchopulmonary dysplasia in very preterm infants: study protocol for a randomized controlled trial

Background

Bronchopulmonary dysplasia (BPD) is still a common complication in very premature infants. At present, there is no effective treatment for BPD. Glucocorticoids are drugs commonly used to prevent or treat BPD before and after birth. In very premature infants with high risk factors for BPD, early use of dexamethasone can reduce the rate of death and/or BPD but may cause long-term adverse neurodevelopmental outcomes. Hydrocortisone (HC), as an alternative drug to dexamethasone, has been increasingly used to prevent BPD. However, no study has reported the efficacy and safety of HC to treat early BPD diagnosed at postnatal day (PND) 28.

Methods

This study protocol is for a multicenter double-blind randomized controlled trial of low-dose HC in the treatment of early BPD. Early BPD infants will be randomly assigned to the HC treatment group or control group. Infants in the HC group will receive 0.5 mg/kg HC twice a day for 7 days and then 0.5 mg/kg HC once a day for 3 days. The control group will be given the same volume of placebo and no intervention on the basis of routine treatment. The primary outcome is survival without moderate or severe BPD at 36 weeks postmenstrual age. Secondary outcomes are the short- and long-term effects on growth, metabolism, neurodevelopment, and other possible complications.

Discussion

This trial will determine the efficacy and safety of low-dose HC administration compared to placebo for the reduction of moderate or severe BPD at 36 weeks postmenstrual age in very preterm infants with early BPD.

Trial registration

China Clinical Trial Registration Center ChiCTR1900021854. Registered on 13 March 2019.

Efficiency of budesonide delivery via a mesh nebulizer in an in-vitro neonatal ventilator model

OBJECTIVE

To determine the delivery efficiency of budesonide aerosol via a mesh nebulizer in a neonatal ventilator model.

DESIGN/METHOD

In an in-vitro ventilated neonatal model, budesonide suspension was administered using a mesh nebulizer. A collection filter was placed distal to the endotracheal tube and budesonide captured by the filter was measured using UV spectroscopy. The ventilator was, in turn, either on high frequency or conventional ventilation mode and the nebulizer was placed either proximal (close to the endotracheal tube) or distal (between the wet side of humidifier and the inspiratory circuit). Each combination (nebulizer position and ventilation mode) to assess budesonide delivery was tested five times.

RESULTS

Overall delivery of budesonide to the distal end of the endotracheal tube a small percentage of the total dose administered. The deposition with conventional ventilation was 2.12% (±1.06) and 1.26% (±0.27), with proximal and distal placement of the nebulizer, respectively. With high-frequency ventilation, the deposition percentages were 1.82% (±0.82) and 1.69% (±0.23), with proximal and distal nebulizer placement, respectively.

CONCLUSION

Only a small percentage of administered budesonide is delivered to the distal endotracheal tube, irrespective of ventilation mode, and nebulizer placement.

Functional outcome at school age of preterm-born children treated with low-dose dexamethasone in infancy

BACKGROUND

Surviving preterm born children, postnatally exposed to high doses of dexamethasone, show an increased risk of neurodevelopmental impairments. Regarding treatment with low doses of dexamethasone, no data exist on outcomes at school age.

AIM

To assess the functional outcome at school age of preterm-born children treated with low-dose dexamethasone.

STUDY DESIGN

In this cohort study, twenty-seven very preterm-born infants treated with dexamethasone from eight days after birth, underwent neuropsychological assessments at age 6-13 years. Their scores were compared with those of the norm population, and scores on total IQ and motor functioning also with those of a preterm reference group, using one-sample-chi-square and student's t-tests.

RESULTS

Compared with the norm population, performance of dexamethasone-treated children was poorer, particularly in the motor domain (mean z-score - 1.81). Dexamethasone-treated children also had lower scores on IQ (-0.29 to -1.12), verbal memory (-0.41 to -0.56), attention (-0.90 to -1.28), and word generation (-0.75). Their parents reported behavioral problems more often. Compared with preterm peers, motor skills remained poor, but total IQs were similar. Adjustment for bronchopulmonary dysplasia did not change our results, because all surviving children had bronchopulmonary dysplasia.

CONCLUSIONS

At school age, the prevalence of adverse motor, cognitive, and behavioral outcomes of preterm-born children treated with low-dose dexamethasone is increased. This could be the consequence of either dexamethasone or BPD.

Neurodevelopmental Outcomes in Children With Liver Diseases: a Systematic Review

OBJECTIVE

The aim of the study was to determine the neurodevelopmental outcomes of children with liver diseases based on a systematical review of the literature.

METHOD

A literature search according to the PRISMA statement was conducted using predefined search terms in PubMed, Cochrane Library, and PsycINFO. The inclusion criterion was studies published from 2000 onwards that reported on the neurodevelopmental outcomes of term-born children with liver diseases. A narrative synthesis was done to appraise the studies.

RESULTS

Twenty-five studies were included (1913 children), 19 of which described children after liver transplantation (LTx; 1372 children). Sixty-seven percentage of the studies on children with liver diseases who survived with their native livers showed low-average or abnormal scores on specific subscales of cognitive and behavioral measures. In studies on children after LTx, this was 82%. After LTx, 83% of studies demonstrated impaired outcomes on behavior, whereas 42% of children received special education. Motor development was impaired in 82% of studies in children with native liver and after LTx.

LIMITATIONS

Studies were heterogenic because of sample sizes, etiology of liver disease and type of assessment tools used.

CONCLUSIONS

More than two-third of included studies showed neurodevelopmental deficits in children with liver diseases, affecting all neurodevelopmental areas. Knowledge on risk factors for impaired neurodevelopment is limited and lack of long-term follow-up is worrying, especially considering the increasing survival rates, resulting in more at-risk patients. Studying early predictors and risk factors of abnormal developmental trajectories of children with liver diseases is indicated to assess strategies to improve their long-term neurodevelopmental outcomes.

Inhaled corticosteroids in ventilated preterm neonates: a non-randomized dose-ranging study

Background

Inhaled corticosteroids (ICS) offer targeted treatment for bronchopulmonary dysplasia (BPD) with minimal systemic effects compared to systemic steroids. However, dosing of ICS in the management of infants at high-risk of developing BPD is not well established. The objective of this study was to determine an effective dose of ICS for the treatment of ventilator-dependent infants to facilitate extubation or reduce fractional inspired oxygen concentration.

Methods

Forty-one infants born at < 32 weeks gestational age (GA) or < 1250 g who were ventilator-dependent at 10–28 days postnatal age were included. A non-randomized dose-ranging trial was performed using aerosolized inhaled beclomethasone with hydrofluoralkane propellant (HFA-BDP). Four dosing groups (200, 400, 600 and 800 μg twice daily for 1 week) with 11, 11, 10 and 9 infants in each group, respectively, were studied. The primary outcome was therapeutic efficacy (successful extubation or reduction in FiO₂ of > 75% from baseline) in ≥60% of infants in the group. Oxygen requirements, complications and long-term neurodevelopmental outcomes were also assessed.

Results

The median age at enrollment was 22 (10–28) postnatal days. The primary outcome, therapeutic efficacy as defined above, was not achieved in any group. However, there was a significant reduction in post-treatment FiO₂ at a dose of 800 μg bid. No obvious trends were seen in long-term neurodevelopmental outcomes.

Conclusions

Therapeutic efficacy was not achieved with all studied doses of ICS. A significant reduction in oxygen requirements was noted in ventilator-dependent preterm infants at 10–28 days of age when given 800 μg of HFA-BDP bid. Larger randomized trials of ICS are required to determine efficacy for the management of infants at high-risk for development of BPD.

Trial registration

This clinical trial was registered retrospectively on clinicaltrials.gov. The registration number is NCT03503994.

Dietary 2-oxoglutarate prevents bone loss caused by neonatal treatment with maximal dexamethasone dose

Synthetic glucocorticoids (GCs) are widely used in the variety of dosages for treatment of premature infants with chronic lung disease, respiratory distress syndrome, allergies, asthma, and other inflammatory and autoimmune conditions. Yet, adverse effects such as glucocorticoid-induced osteoporosis and growth retardation are recognized. Conversely, 2-oxoglutarate (2-Ox), a precursor of glutamine, glutamate, and collagen amino acids, exerts protective effects on bone development. Our aim was to elucidate the effect of dietary administered 2-Ox on bone loss caused by neonatal treatment with clinically relevant maximal therapeutic dexamethasone (Dex) dose. Long bones of neonatal female piglets receiving Dex, Dex+2-Ox, or untreated were examined through measurements of mechanical properties, density, mineralization, geometry, histomorphometry, and histology. Selected hormones, bone turnover, and growth markers were also analyzed. Neonatal administration of clinically relevant maximal dose of Dex alone led to over 30% decrease in bone mass and the ultimate strength ( P < 0.001 for all). The length (13 and 7% for femur and humerus, respectively) and other geometrical parameters (13-45%) decreased compared to the control ( P < 0.001 for all). Dex impaired bone growth and caused hormonal imbalance. Dietary 2-Ox prevented Dex influence and vast majority of assessed bone parameters were restored almost to the control level. Piglets receiving 2-Ox had heavier, denser, and stronger bones; higher levels of growth hormone and osteocalcin concentration; and preserved microarchitecture of trabecular bone compared to the Dex group. 2-Ox administered postnatally had a potential to maintain bone structure of animals simultaneously treated with maximal therapeutic doses of Dex, which, in our opinion, may open up a new opportunity in developing combined treatment for children treated with GCs. Impact statement The present study has showed, for the first time, that dietary 2-oxoglutarate (2-Ox) administered postnatally has a potential to improve/maintain bone structure of animals simultaneously treated with maximal therapeutic doses of dexamethasone (Dex). It may open the new direction in searching and developing combined treatment for children treated with glucocorticoids (GCs) since growing group of children is exposed to synthetic GCs and adverse effects such as glucocorticoid-induced osteoporosis and growth retardation are recognized. Currently proposed combined therapies have numerous side effects. Thus, this study proposed a new direction in combined therapies utilizing dietary supplementation with glutamine derivative. Impairment caused by Dex in presented long bones animal model was prevented by dietary supplementation with 2-Ox and vast majority of assessed bone parameters were restored almost to the control level. These results support previous thesis on the regulatory mechanism of nutrient utilization regulated by glutamine derivatives and enrich the nutritional science.

RETRACTED: Evaluation of behavioral problems after prenatal dexamethasone treatment in Swedish adolescents at risk of CAH

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the authors due to technical errors that have called into question the reliability of the data used to inform the author's conclusions. All data on cognitive and behavioral outcomes in CAH and non–CAH cases, treated or not treated with DEX prenatally, were put into a single Excel database. The authors had in total four different patient groups for each age group (5–6 y, 7–17 y and 18-35 y). The database consisted of 237 cases in total and there were multiple columns for the different outcome measures. When the behavioral data for the sub-cohort described in this paper (first trimester treated non-CAH cases and healthy population controls, age 7–17 y) were copied to another sheet and compressed/modified in preparation for statistical analysis in SPSS, an error occurred. This technological issue caused rows to shift and the data from the different groups got mixed up. In particular, the non–CAH group versus the control group were "contaminated" with cases from the wrong patient group. The authors discovered this mistake when they started to analyse the data from the other sub–groups of patients, the CAH cases and the adult cohort, which was after their original results had already been published in Hormones and Behavior in this manuscript "Evaluation of behavioral problems after prenatal dexamethasone treatment in Swedish adolescents at risk of CAH". It then became apparent that the entire data set was unreliable and needed to be re–analysed which is what has motivated the retraction of this article. The authors have recently completed this re–analysis and the results have been published here: https://www.sciencedirect.com/science/article/pii/S0018506X17300752

Bronchopulmonary Dysplasia Within and Beyond the Neonatal Unit

BACKGROUND

Bronchopulmonary dysplasia (BPD), also known as chronic lung disease of prematurity or chronic neonatal lung disease, is a major cause of respiratory illness in premature babies. Newborn babies survive at gestational ages of 23 to 26 weeks, earlier than when BPD was first described. New mechanisms of lung injury have therefore emerged and the clinical and pathological characteristics of pulmonary involvement have changed.

PURPOSE

Improved neonatal intensive care unit modalities have increased survival rates; the overall prevalence of the condition, however, has not changed. Management of evolving BPD aims at minimizing lung injury. Management of established, especially severe BPD, still poses significant clinical challenge as these babies need long-term oxygen therapy (LTOT) for variable length of time. We aim to give an overview of management of established BPD with particular focus on weaning home oxygen therapy at our local center in the United Kingdom.

SEARCH AND RESULTS

On the basis of most recent evidence, we concluded that an integrated pathway for managing babies on LTOT is very important after discharge from neonatal unit.

IMPLICATIONS FOR PRACTICE

A structured weaning pathway for premature babies on home oxygen improves outcome.

IMPLICATIONS FOR RESEARCH

The management of severe BPD and related complications, particularly during the first 2 years of life, remains a continuing challenge for parents and healthcare providers. The most beneficial respiratory support strategy to minimize lung injury and/or promote lung healing remains unclear and requires further investigation.

Behavioural and neurodevelopmental outcome of 2-year-old children after preterm premature rupture of membranes: follow-up of a randomised clinical trial comparing induction of labour and expectant management

OBJECTIVE

We recently reported that induction of labour does not improve short term neonatal outcome in women with late preterm premature rupture of membranes (PPROM) as compared to expectant management (PPROMEXIL trial). In this study the neurodevelopmental and behavioural outcome of the children from this trial at 2 years of age was studied.

STUDY DESIGN

We studied outcome of offspring of women randomised in the PPROMEXIL study. These women had >24h of ruptured membranes and were between 34 and 37 weeks of pregnancy when they were randomised to induction of labour (IoL) or expectant management (EM). Two years after delivery, the parents received the ages and stages questionnaire (ASQ), the child behaviour checklist (CBCL) and a general questionnaire.

RESULTS

Follow-up data were obtained from 234 children (121 after IoL, 113 after EM, response rate 59% (44% of the original 532 randomised women)). In the IoL group 16 children (14%) had an abnormal score in ≥1 domains of the ASQ, versus 27 (26%) in the EM group (difference in percentage -11.4 (95% CI -21.9 to -0.98; p=0.033)). For the CBCL, an abnormal score was found in 13% (n=15) in the IoL group and in 15% (n=16) in the EM group (difference in percentage -2.13 (95% CI -11.2 to 6.94; p=0.645)).

CONCLUSION

Although a policy of induction of labour in women with late PPROM does not improve short term neonatal outcome, it might be associated with a decrease in neurodevelopmental difficulties at the age of two years as compared to expectant management. Expectant management did not lead to a difference in behavioural problems.

Neonatal drug therapy: The first frontier of therapeutics for children

Knowledge about the safe and effective use of medicines in neonates has increased substantially but has resulted in few label changes. Drugs developed for use in adults are reshaped and tailored to specific neonatal indications. However, the use of drugs in neonates should not only mirror adult pharmacotherapy, but should be driven by their own specific needs. Therefore, building collaborative networks may assist to develop a newborn-driven research agenda addressing their clinical needs and diseases.

The Cochrane Library and safety of systemic corticosteroids for acute respiratory conditions in children: an overview of reviews

BACKGROUND

Acute respiratory conditions are a leading cause of childhood morbidity and mortality. Corticosteroids are effective and established treatments in some acute respiratory infections (e.g. croup) and asthma exacerbations; however, their role is controversial in other conditions owing to inconsistent effectiveness or safety concerns (e.g. bronchiolitis, acute wheeze).

OBJECTIVES

To examine clinically relevant short-term safety outcomes related to acute single or recurrent systemic short-term (<2 weeks) corticosteroid use based on systematic reviews of acute respiratory conditions.

METHODS

We searched the Cochrane Database of Systematic Reviews in February 2013 for systematic reviews comparing systemic corticosteroids with placebo for children (aged 0-18 years) with acute asthma, preschool wheezing, bronchiolitis, croup, pharyngitis/tonsillitis or pneumonia. We selected the following outcomes a priori: gastrointestinal (GI) bleeding and abdominal pain; behavioural effects (tremor or hyperactivity, jitteriness, irritability or emotional distress); hypertension; serious adverse events, including death, length of stay in hospital; and relapse leading to hospitalization. One reviewer extracted data and another reviewer independently verified data. Results were combined using Peto odds ratios and risk differences (RD) for dichotomous outcomes and mean differences for continuous outcomes.

MAIN RESULTS

Seven reviews containing 44 relevant randomized controlled trials were included. Three reviews were on asthma and one each on bronchiolitis, croup, wheeze and pharyngitis/tonsillitis. Six trials (2114 patients) assessed GI bleeding and/or abdominal pain and showed no significant differences between corticosteroids and placebo (1.5% vs. 1.8%, respectively). Various behavioural effects and hypertension/blood pressure were measured in four trials each (838 and 1617 patients, respectively), with no significant differences reported. None of the trials reported deaths in any of the treatment groups. Based on 17 trials (2056 patients), there were significantly fewer admissions at day 1 with corticosteroids (risk differences = -0.11, 95% confidence interval -0.18 to -0.05; Peto odds ratios = 0.63, 95% confidence interval 0.52 to 0.78). Based on 16 trials (1502 patients) corticosteroids resulted in over 8 fewer hours in hospital compared with placebo (mean differences = -8.49 hours, 95% confidence interval -1.76 to -3.23). There were significantly fewer relapses leading to hospitalization (13 trials, 1099 patients) with corticosteroids (Peto odds ratios 0.42, 95% confidence interval 0.23 to 0.76). While differences favouring corticosteroids in hospital-related outcomes were restricted to asthma and/or croup, we did not find any increase in hospital admission at day 1, length of stay or re-hospitalization in the other acute respiratory conditions.

AUTHORS' CONCLUSIONS

Practitioners may prescribe systemic corticosteroids in otherwise healthy children when indicated for the management of acute respiratory conditions (i.e. infections or asthma exacerbations) with minimal concern about short-term adverse effects.

Functional outcome at school age of preterm-born children treated with high-dose dexamethasone

BACKGROUND

Postnatal dexamethasone (DXM) treatment is associated with adverse motor outcome. It is largely unknown as to what extent functional outcome at school age is affected.

AIMS

Our first aim was to determine motor, cognitive, and behavioural outcome at school age of preterm-born children treated with high-dose DXM for pulmonary problems. Our second aim was to identify DXM-related risk factors for adverse outcome.

STUDY DESIGN

In this cohort study, we included 53 very preterm-born children treated with DXM (starting dose 0.5mg/kg/d) after the first week of life. At the median age of 9 years, we performed a detailed neuropsychological assessment.

RESULTS

Compared to the norm population, DXM-treated children scored worse on the Movement-ABC (abnormal fine motor, ball skills and balance: 59%, 47% and 30%, respectively). They more often had total (36%), verbal (32%) and performance IQs (55%) below 85 (P<.001, P=.002, P<.001, respectively). On each of the remaining measures, DXM-treated children scored worse than the norm population, except for verbal long-term memory and verbal recognition memory. DXM-related risk factors were associated with poorer performance.

CONCLUSIONS

At school age, multiple domains of functional outcome were affected in DXM-treated children. Risk factors related to the use of DXM should be considered as serious potentiaters of adverse outcome in children treated with high-dose DXM.

Neonatal clinical pharmacology

Effective and safe drug administration in neonates should be based on integrated knowledge on the evolving physiological characteristics of the infant who will receive the drug and the pharmacokinetics (PK) and pharmacodynamics (PD) of a given drug. Consequently, clinical pharmacology in neonates is as dynamic and diverse as the neonates we admit to our units while covariates explaining the variability are at least as relevant as median estimates. The unique setting of neonatal clinical pharmacology will be highlighted based on the hazards of simple extrapolation of maturational drug clearance when only based on 'adult' metabolism (propofol, paracetamol). Second, maturational trends are not at the same pace for all maturational processes. This will be illustrated based on the differences between hepatic and renal maturation (tramadol, morphine, midazolam). Finally, pharmacogenetics should be tailored to neonates, not just mirror adult concepts. Because of this diversity, clinical research in the field of neonatal clinical pharmacology is urgently needed and facilitated through PK/PD modeling. In addition, irrespective of already available data to guide pharmacotherapy, pharmacovigilance is needed to recognize specific side effects. Consequently, pediatric anesthesiologists should consider to contribute to improved pharmacotherapy through clinical trial design and collaboration, as well as reporting on adverse effects of specific drugs.

Development of fine motor skills in preterm infants

Fine motor skills are related to functioning in daily life and at school. We reviewed the status of knowledge, in preterm children, on the development of fine motor skills, the relation with gross motor skills, and risk factors for impaired fine motor skills. We searched the past 15 years in PubMed, using ['motor skills' or 'fine motor function' and 'preterm infant'] as the search string. Impaired gross and fine motor skills are among the most frequently occurring problems encountered by preterm children who do not develop cerebral palsy. The prevalence is around 40% for mild to moderate impairment and 20% for moderate impairment. Fine motor skill scores on the Movement Assessment Battery for Children are about 0.62 of a standard deviation lower compared with term children. Risk factors for fine motor impairments include moderately preterm birth (odds ratio [OR] 2.0) and, among very preterm children (<32 wk gestation), intra-uterine growth restriction (ORs 2-3), inflammatory conditions (late-onset sepsis and necrotizing enterocolitis, ORs 3-5), and dexamethasone therapy for bronchopulmonary dysplasia (OR 2.7). A better understanding of factors that play a role in the development of and recovery from brain injury could guide future intervention attempts aimed at improving fine motor skills of preterm children.

Antenatal dexamethasone after asphyxia increases neural injury in preterm fetal sheep

BACKGROUND AND PURPOSE

Maternal glucocorticoid treatment for threatened premature delivery dramatically improves neonatal survival and short-term morbidity; however, its effects on neurodevelopmental outcome are variable. We investigated the effect of maternal glucocorticoid exposure after acute asphyxia on injury in the preterm brain.

METHODS

Chronically instrumented singleton fetal sheep at 0.7 of gestation received asphyxia induced by complete umbilical cord occlusion for 25 minutes. 15 minutes after release of occlusion, ewes received a 3 ml i.m. injection of either dexamethasone (12 mg, n = 10) or saline (n = 10). Sheep were killed after 7 days recovery; survival of neurons in the hippocampus and basal ganglia, and oligodendrocytes in periventricular white matter were assessed using an unbiased stereological approach.

RESULTS

Maternal dexamethasone after asphyxia was associated with more severe loss of neurons in the hippocampus (CA3 regions, 290 ± 76 vs 484 ± 98 neurons/mm(2), mean ± SEM, P<0.05) and basal ganglia (putamen, 538 ± 112 vs 814 ± 34 neurons/mm(2), P<0.05) compared to asphyxia-saline, and with greater loss of both total (913 ± 77 vs 1201 ± 75/mm(2), P<0.05) and immature/mature myelinating oligodendrocytes in periventricular white matter (66 ± 8 vs 114 ± 12/mm(2), P<0.05, vs sham controls 165 ± 10/mm(2), P<0.001). This was associated with transient hyperglycemia (peak 3.5 ± 0.2 vs. 1.4 ± 0.2 mmol/L at 6 h, P<0.05) and reduced suppression of EEG power in the first 24 h after occlusion (maximum -1.5 ± 1.2 dB vs. -5.0 ± 1.4 dB in saline controls, P<0.01), but later onset and fewer overt seizures.

CONCLUSIONS

In preterm fetal sheep, exposure to maternal dexamethasone during recovery from asphyxia exacerbated brain damage.

Educational paper: do we need neonatal clinical pharmacologists?

Effective and safe drug administration in young infants should be based on integrated knowledge concerning the evolving physiological characteristics of the infant who will receive the drug and the pharmacokinetic and pharmacodynamic characteristics of a given drug. Consequently, clinical pharmacology in neonates is as dynamic and diverse as the neonates we are entitled to take care of. Even more than median estimates, covariates of variability within the population are of clinical relevance. We aim to illustrate the complexity and the need for neonatal clinical pharmacology based on the gap between current and likely best clinical practice for two commonly administered compounds (aminoglycosides for infection and ibuprofen for patent ductus arteriosus) and one new compound (bevacizumab, to treat threshold retinopathy of prematurity). Progression has been made to render pharmacokinetic studies child size, e.g., low volume samples, optimal study design, and population pharmacokinetics. Challenges to further improve clinical pharmacology in neonates include, when appropriate, the validation of off-patent drug dosing regimens and of infant-tailored formulations. Knowledge integration, i.e., the use of available data to improve current drug use and to predict pharmacokinetics/pharmacodynamics for similar compounds is needed. Development of clinical research networks is helpful to achieve these goals.

The role of glucocorticoid receptors in dexamethasone-induced apoptosis of neuroprogenitor cells in the hippocampus of rat pups

Background. Dexamethasone (Dex) has been used to reduce inflammation in preterm infants with assistive ventilation and to prevent chronic lung diseases. However, Dex treatment results in adverse effects on the brain. Since the hippocampus contains a high density of glucocorticoid receptors (GCRs), we hypothesized that Dex affects neurogenesis in the hippocampus through inflammatory mediators. Methods. Albino Wistar rat pups first received a single dose of Dex (0.5 mg/kg) on postnatal day 1 (P1) and were sacrificed on P2, P3, P5, and P7. One group of Dex-treated pups (Dex-treated D1D2) was given mifepristone (RU486, a GCR antagonist) on P1 and sacrificed on P2. Hippocampi were isolated for western blot analysis, TUNEL, cleaved-caspase 3 staining for cell counts, and morphological assessment. Control pups received normal saline (NS). Results. Dex reduced the developmental gain in body weight, but had no effect on brain weight. In the Dex-treated D1D2 group, apoptotic cells increased in number based on TUNEL and cleaved-caspase 3 staining. Most of the apoptotic cells expressed the neural progenitor cell marker nestin. Dex-induced apoptosis in P1 pups was markedly reduced (60%) by pretreatment with RU486, indicating the involvement of GCRs. Conclusion. Early administration of Dex results in apoptosis of neural progenitor cells in the hippocampus and this is mediated through GCRs.

Neurodevelopmental outcome of preterm very low birth weight infants born from 2005 to 2007

OBJECTIVE

To evaluate short-term neurodevelopmental outcome (at 24 months of corrected age) and correlations with obstetric and neonatal factors in a sample of preterm very low birth weight infants born and admitted to an Italian tertiary centre between 2005 and 2007.

METHODS

156 infants with a birth weight ≤ 1500 g (gestational age, range: 27-31 weeks) were followed at regular intervals through neurodevelopmental (neurological and psychomotor) assessment up to 24 months of corrected age. A statistical analysis was conducted in order to look for correlations between pre- and perinatal variables and neuropsychomotor outcome at 24 months.

RESULTS

131 children were classified as normal and the other 25 presented sequelae classified as "minor" in 17 cases and as "major" in eight. The most significant risk factors for a poor outcome were preterm premature rupture of the membranes, bronchodysplasia, late-onset sepsis, postnatal steroid therapy and male gender. The presence of severe abnormalities on brain ultrasound scan and of an abnormal neurological assessment at 40 weeks at term equivalent age were strong predictors of poor outcome.

CONCLUSIONS

Our study is one of the few investigating the short-term outcome of preterm VLBW Italian children born in the second half of the 2000s. Neurodevelopmental assessment at 24 months revealed a marked reduction in major sequelae. Several risk factors for a poor neurodevelopmental outcome identified in children born in earlier periods were confirmed in these children born in recent years.

Glucocorticoids and preterm hypoxic-ischemic brain injury: the good and the bad

Fetuses at risk of premature delivery are now routinely exposed to maternal treatment with synthetic glucocorticoids. In randomized clinical trials, these substantially reduce acute neonatal systemic morbidity, and mortality, after premature birth and reduce intraventricular hemorrhage. However, the overall neurodevelopmental impact is surprisingly unclear; worryingly, postnatal glucocorticoids are consistently associated with impaired brain development. We review the clinical and experimental evidence on how glucocorticoids may affect the developing brain and highlight the need for systematic research.

Prenatal rosiglitazone administration to neonatal rat pups does not alter the adult metabolic phenotype

Prenatally administered rosiglitazone (RGZ) is effective in enhancing lung maturity; however, its long-term safety remains unknown. This study aimed to determine the effects of prenatally administered RGZ on the metabolic phenotype of adult rats. Methods. Pregnant Sprague-Dawley rat dams were administered either placebo or RGZ at embryonic days 18 and 19. Between 12 and 20 weeks of age, the rats underwent glucose and insulin tolerance tests and de novo fatty acid synthesis assays. The lungs, liver, skeletal muscle, and fat tissue were processed by Western hybridization for peroxisome proliferator-activated receptor (PPAR)γ, adipose differentiation-related protein (ADRP), and surfactant proteins B (SPB) and C (SPC). Plasma was assayed for triglycerides, cholesterol, insulin, glucagon, and troponin-I levels. Lungs were also morphometrically analyzed. Results. Insulin and glucose challenges, de novo fatty acid synthesis, and all serum assays revealed no differences among all groups. Western hybridization for PPARγ, ADRP, SPB, and SPC in lung, liver, muscle, and fat tissue showed equal levels. Histologic analyses showed a similar number of alveoli and septal thickness in all experimental groups. Conclusions. When administered prenatally, RGZ does not affect long-term fetal programming and may be safe for enhancing fetal lung maturation.

Staging perspectives in neurodevelopmental aspects of neuropsychiatry: agents, phases and ages at expression

Neurodevelopmental risk factors have assumed a critical role in prevailing notions concerning the etiopathogenesis of neuropsychiatric disorders. Staging, diagnostic elements at which phase of disease is determined, provides a means of conceptualizing the degree and extent of factors affecting brain development trajectories, but is concurrently specified through the particular interactions of genes and environment unique to each individual case. For present purposes, staging perspectives in neurodevelopmental aspects of the disease processes are considered from conditions giving rise to neurodevelopmental staging in affective states, adolescence, dopamine disease states, and autism spectrum disorders. Three major aspects influencing the eventual course of individual developmental trajectories appear to possess an essential determinant influence upon outcome: (i) the type of agent that interferes with brain development, whether chemical, immune system activating or absent (anoxia/hypoxia), (ii) the phase of brain development at which the agent exerts disruption, whether prenatal, postnatal, or adolescent, and (iii) the age of expression of structural and functional abnormalities. Clinical staging may be assumed at any or each developmental phase. The present perspective offers both a challenge to bring further order to diagnosis, intervention, and prognosis and a statement regarding the extreme complexities and interwoven intricacies of epigenetic factors, biomarkers, and neurobehavioral entities that aggravate currents notions of the neuropsychiatric disorders.

Neonatal dexamethasone treatment in the rat leads to kidney damage in adulthood

Recently, concern has been raised that corticosteroid treatment of preterm neonates might be associated with adverse effects later in life, including early development of hypertension. Here, we investigate the impact of neonatal dexamethasone (Dex) treatment on early renal cell proliferation and nephron number. We analyzed mitotic activity in renal cortex of rat pups neonatally treated with Dex. Nephron number was measured and possible renal damage was quantified by counting inflammatory foci, ED-1 positive cells (macrophages), and the desmin score (activated podocytes). Mitotic activity was 34 and 29% lower on d 2 and 4 in Dex-treated rats compared with saline-treated controls. The number of glomeruli was lower at 4 wk, but nephron size was unchanged after Dex treatment, as calculated from glomerular density and (lower) body- and kidney weight. At wk 50, the glomerular number was significantly lower in Dex-treated rats, whereas body and kidney weight were the same as in Sal controls. Dex rats also showed more kidney damage, manifested by a approximately 3.5-fold increase in inflammation foci/mm and in ED-1 positive cells/mm and a approximately 4.3-fold increased desmin score. Temporary suppression of mitotic activity during neonatal Dex treatment leads to reduction of nephron number and more kidney damage later in life.