The adverse neuro-developmental effects of postnatal steroids in the preterm infant: a systematic review of RCTs

Randomized Trial of 42-Day Compared with 9-Day Courses of Dexamethasone for the Treatment of Evolving Bronchopulmonary Dysplasia in Extremely Preterm Infants

OBJECTIVE

To compare pulmonary and neurodevelopmental outcomes in extremely preterm infants with evolving bronchopulmonary dysplasia treated with either a 42-day course of dexamethasone or 9-day course(s) of dexamethasone.

STUDY DESIGN

This was a prospective, randomized study in 59 infants ≤27 weeks of gestation born between October 2006 and December 2010, who at day 10-21 of life had ventilatory support with mean airway pressure ≥8 cm H₂O and FiO₂ ≥60%. Infants received dexamethasone 0.5 mg/k/day × 3 days followed by a slow taper (42-day group, n = 30) or dexamethasone 0.5 mg/k/day followed by a rapid taper (9-day group, n = 29). Infants in the 9-day group received additional 9-day courses if they again required entry support. The primary outcome was intact survival (normal neurologic examination, IQ >70, and functioning in school without supplemental educational support) at 7 years of age.

RESULTS

The 42-day and 9-day groups were similar for mean gestational age (25 weeks) and all baseline characteristics. Nineteen of 29 infants (66%) in the 9-day group received only 1 course of dexamethasone; therefore, the total steroid dose for the 42-day group (7.56 mg/kg) was significantly greater than that for the 9-day group (4.04 mg/kg), P < .001. Infants in the 42-day group had shorter duration of ventilation (25 vs 37 days), P < .005, received fewer transfusions (2 vs 3.5), P < .01, and reached full enteral feeds earlier (40 vs 46 days), P < .05. Intact survival at school age was significantly increased in the 42-day group (75%) compared with the 9-day group (34%), P < .005.

CONCLUSION

A 42-day tapering course of dexamethasone in extremely preterm infants at high risk for bronchopulmonary dysplasia decreased hospital morbidities and increased rate of survival without handicap compared with a treatment protocol that attempted to minimize steroid exposure.

Bronchopulmonary dysplasia: Pathophysiology and potential anti-inflammatory therapies

Inflammation of the preterm lungs is key to the pathogenesis of bronchopulmonary dysplasia (BPD), whether it arises as a consequence of intrauterine inflammation or postnatal respiratory management. This review explores steroidal and non-steroidal therapies for reducing neonatal pulmonary inflammation, aimed at treating or preventing BPD.

Timing of postnatal corticosteroid treatment for bronchopulmonary dysplasia and its effect on outcomes

OBJECTIVE

To determine the association of timing of steroid therapy for bronchopulmonary dysplasia (BPD) and outcomes.

METHODS

Retrospective cohort study of preterm infants treated with low-dose dexamethasone for BPD. Infants treated with steroids at day of life (DOL) 14-28 (moderately late group) were compared to infants treated at DOL 29-42 (delayed group). Inverse probability of treatment weighting (IPTW) adjusted propensity scores were used to correct for potential confounders. The primary outcome of interest was postmenstrual age (PMA) at discharge.

RESULTS

Fifty-five infants (25 with moderately late treatment; 30 with delayed treatment) were identified. The mean age at treatment was 23 days in the moderately late group and 35 days in the delayed group. At time of treatment, infants treated moderately late were more likely to be on high frequency ventilation (96% vs 47%, P < 0.0001) and had higher fraction of inspired oxygen (70.7 ± 17.9% vs 56.2 ± 18.4%, P = 0.005) compared to infants treated later. Despite being the sicker group, moderately late treated infants were discharged at an earlier corrected age compared to infants with delayed treatment (PMA 42.9 ± 4.5 vs 47.5 ± 8.3 weeks, IPTW adjusted P = 0.03). Moderately late treatment was also associated with fewer days on mechanical ventilation (46.0 ± 19.0 days vs 77.4 ± 67.0 days, IPTW adjusted P = 0.02) and fewer days on supplemental oxygen (114.3 ± 40.8 days vs 149.8 ± 57.0 days, IPTW adjusted P = 0.005).

CONCLUSIONS

Among preterm infants at high risk of BPD, delaying treatment with postnatal steroids is associated with comparatively worse short-term outcomes as compared to earlier treatment.

Development and validation of an assay for quantifying budesonide in dried blood spots collected from extremely low gestational age neonates

Budesonide is a potential therapeutic option for the prevention of bronchopulmonary dysplasia in mechanically ventilated premature neonates. The dose and concentrations of budesonide that drive effective prophylaxis are unknown, due in part to the difficulty in obtaining serial blood samples from this fragile population. Of primary concern is the limited total blood volume available for collection for the purposes of a pharmacokinetic study. Dried blood spots (DBS), which require the collection of <200 μL whole blood to fill an entire card, are an attractive low-blood volume alternative to traditional venipuncture sampling. We describe a simple and sensitive method for determining budesonide concentrations in DBS using an ultra-high-performance liquid chromatography - tandem mass spectrometry assay. Budesonide was liberated from a single 6 mm punch using a basified methyl tert-butyl ether extraction procedure. The assay was determined to be accurate and precise in the dynamic range of 1 to 50 ng/mL. The validated assay was then successfully applied to DBS collected as part of a multi-center, dose-escalation study of budesonide administered in surfactant via intra-tracheal instillation to premature neonates between 23 and 28 weeks gestational age. These findings show that DBS are a useful technique for collecting pharmacokinetic samples in premature neonates and other pediatric populations.

Duration of Pediatric Clinical Trials Submitted to the US Food and Drug Administration

Importance

The increasing prevalence of pediatric chronic disease has resulted in increased exposure to long-term drug therapy in children. The duration of recently completed drug trials that support approval for drug therapy in children with chronic diseases has not been systematically evaluated. Such information is a vital first step in forming safety pharmacovigilance strategies for drugs used for long-term therapy in children.

Objective

To characterize the duration of clinical trials submitted to the US Food and Drug Administration (FDA) for pediatric drug approvals, with a focus on drugs used for long-term therapy.

Design and Setting

A review was performed of all safety and efficacy clinical trials conducted under the Best Pharmaceuticals for Children Act or the Pediatric Research Equity Act and submitted to the FDA from September 1, 2007, to December 31, 2014, to support the approval of drugs frequently used for long-term therapy in children. Statistical analysis was performed from July 1, 2015, to December 31, 2017.

Main Outcomes and Measures

Maximum duration of trials submitted to support FDA approval of drugs for children.

Results

A total of 306 trials supporting 86 drugs intended for long-term use in children were eligible for the primary analysis. The drugs most commonly evaluated were for treatment of neurologic (25 [29%]), pulmonary (16 [19%]), and anti-infective (14 [16%]) indications. The median maximum trial duration by drug was 44 weeks (minimum, 1.1 week; maximum, 364 weeks). For nearly two-thirds of the drugs (52 [61%]), the maximum trial duration was less than 52 weeks. For 10 of the drugs (12%), the maximum trial duration was 3 years or more. Maximum duration of trials did not vary by therapeutic category, minimum age of enrollment, calendar year, or legislative mandate.

Conclusions and Relevance

Pediatric clinical trials designed to sufficiently investigate drug safety and efficacy to support FDA approval are of relatively limited duration. Given the potential long-term exposure of patients to these drugs, the clinical community should consider whether new approaches are needed to better understand the safety associated with long-term use of these drugs.

Cerebellar hypoplasia of prematurity: Causes and consequences

As magnetic resonance imaging has been increasingly used to study brain injury and brain development in premature newborns, the prevalence of cerebellar abnormalities is increasingly recognized. The preterm cerebellum is highly vulnerable to a number of insults during its critical phase of growth and development throughout the period of prematurity and beyond. Direct cerebellar injury and additional factors such as supratentorial brain injury and glucocorticoid exposure adversely impact cerebellar growth and, consequently, increase the risk of neurodevelopmental disabilities. In this chapter the causes and consequences of cerebellar hypoplasia of prematurity are reviewed.

Pulmonary interstitial glycogenosis: Diagnostic evaluation and clinical course

OBJECTIVES

We sought to describe the phenotype for patients with P.I.G. including presentation, evaluation, cardiac co-morbidities, high resolution computed tomography findings, and outcomes.

METHODS

With institutional review board approval, we performed a retrospective review of patients with biopsy-proven P.I.G. Biopsies, high resolution chest computed tomography, and cardiac evaluations were reviewed and characterized by experts in each field.

RESULTS

Sixty-two percent of the patients were male. The median gestational age was 37 weeks (range 27-40). The median age at biopsy was 1.6 months (range 0.3-6 months). Structural heart disease was present in 63% of patients. Pulmonary hypertension (diagnosed by echocardiogram and/or cardiac catheterization) was noted in 38% of patients. Alveolar simplification was present in 79% of patients. Fifty percent of available biopsies revealed patchy disease. An increase in age at biopsy was associated with patchy (vs diffuse) disease. Ninety-two percent of patients were treated with systemic corticosteroids. Median age at last follow-up was 1234 days with a range of 37 days to 15 years. At the time of last follow-up, 12 patients were off all support, eight were on supplemental oxygen, two were mechanically ventilated, one underwent lung transplantation, and one died. CT findings commonly included ground glass opacities (86%) and cystic change (50%).

CONCLUSIONS

The P.I.G. phenotype has not been comprehensively described, and poor recognition and misconceptions about P.I.G. persist. P.I.G. is a disease that presents in early infancy, requires significant medical intervention, and frequently is seen in association with alveolar simplification and/or cardiovascular disease. CT findings include ground glass opacities and cysts. Patients should be monitored for pulmonary hypertension. Without life-threatening comorbidities, many patients do well over time, although respiratory symptoms may persist into adolescence.

Preterm Birth and the Risk of Neurodevelopmental Disorders - Is There a Role for Epigenetic Dysregulation?

Preterm Birth (PTB) accounts for approximately 11% of all births worldwide each year and is a profound physiological stressor in early life. The burden of neuropsychiatric and developmental impairment is high, with severity and prevalence correlated with gestational age at delivery. PTB is a major risk factor for the development of cerebral palsy, lower educational attainment and deficits in cognitive functioning, and individuals born preterm have higher rates of schizophrenia, autistic spectrum disorder and attention deficit/hyperactivity disorder. Factors such as gestational age at birth, systemic inflammation, respiratory morbidity, sub-optimal nutrition, and genetic vulnerability are associated with poor outcome after preterm birth, but the mechanisms linking these factors to adverse long term outcome are poorly understood. One potential mechanism linking PTB with neurodevelopmental effects is changes in the epigenome. Epigenetic processes can be defined as those leading to altered gene expression in the absence of a change in the underlying DNA sequence and include DNA methylation/hydroxymethylation and histone modifications. Such epigenetic modifications may be susceptible to environmental stimuli, and changes may persist long after the stimulus has ceased, providing a mechanism to explain the long-term consequences of acute exposures in early life. Many factors such as inflammation, fluctuating oxygenation and excitotoxicity which are known factors in PTB related brain injury, have also been implicated in epigenetic dysfunction. In this review, we will discuss the potential role of epigenetic dysregulation in mediating the effects of PTB on neurodevelopmental outcome, with specific emphasis on DNA methylation and the α-ketoglutarate dependent dioxygenase family of enzymes.

Evaluating the use of corticosteroids in preventing and treating bronchopulmonary dysplasia in preterm neonates

Approximately 15 million babies worldwide are born premature, and complications of prematurity are one of the leading causes of death in neonates. Neonatal respiratory distress syndrome (NRDS) and bronchopulmonary dysplasia (BPD) are two of the most common and serious consequences of prematurity. Synthetic corticosteroids, including dexamethasone, have been central in efforts to treat and prevent BPD. There is strong evidence to show that prenatal corticosteroids reduce infant mortality and the incidence of NRDS, leading to their widespread use in obstetric units. However, data suggest that they are not as effective in reducing the incidence of BPD as NRDS, which may be due to the multifactorial pathogenesis of BPD. On the other hand, the use of postnatal corticosteroids in preterm infants is much more controversial. They have been shown to improve lung function and help in reducing the need for mechanical ventilation. These benefits, however, are associated with a range of adverse short- and long-term effects. This review will discuss the benefits and consequences of corticosteroids in treating BPD and will examine alternative treatments and future research that may improve the understanding of BPD and inform clinical practice.

Usefulness of an Online Risk Estimator for Bronchopulmonary Dysplasia in Predicting Corticosteroid Treatment in Infants Born Preterm

OBJECTIVE

To assess the usefulness of a bronchopulmonary dysplasia (BPD) outcome estimator developed by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) in identifying high-risk preterm infants treated with steroids.

STUDY DESIGN

This was a single-center retrospective study of infants born ≤30 weeks of gestational age. The NICHD BPD outcome estimator was used to retrospectively calculate BPD risk at various postnatal ages. The best combination of risk estimates for identifying steroid treatment was identified using stepwise model selection. A cut-off value with the best combination of sensitivity and specificity was identified using receiver operating characteristic analysis.

RESULTS

A total of 165 infants born preterm (mean gestational age 26 ± 1.6 weeks, mean birth weight 837 ± 171 g) were included. Of these, 61 were treated with steroids for BPD and 104 were not. Risk estimates for BPD or death were significantly greater in infants treated with steroids compared with controls. Both combined risk for severe BPD or death and single risk of no BPD were identified as factors with the best predictive power for identifying treatment with steroids, with accurate prediction possible as early as the second week of life. A greater than 37% risk for severe BPD or death or a less than 3% risk of no BPD on day of life 14 had 84%-92% sensitivity and 77%-80% specificity for predicting steroid treatment.

CONCLUSION

The NICHD BPD outcome estimator can be a useful objective tool for identifying infants at high risk for BPD who may benefit from postnatal steroids.

The Potentials and Caveats of Mesenchymal Stromal Cell-Based Therapies in the Preterm Infant

Preponderance of proinflammatory signals is a characteristic feature of all acute and resulting long-term morbidities of the preterm infant. The proinflammatory actions are best characterized for bronchopulmonary dysplasia (BPD) which is the chronic lung disease of the preterm infant with lifelong restrictions of pulmonary function and severe consequences for psychomotor development and quality of life. Besides BPD, the immature brain, eye, and gut are also exposed to inflammatory injuries provoked by infection, mechanical ventilation, and oxygen toxicity. Despite the tremendous progress in the understanding of disease pathologies, therapeutic interventions with proven efficiency remain restricted to a few drug therapies with restricted therapeutic benefit, partially considerable side effects, and missing option of applicability to the inflamed brain. The therapeutic potential of mesenchymal stromal cells (MSCs)—also known as mesenchymal stem cells—has attracted much attention during the recent years due to their anti-inflammatory activities and their secretion of growth and development-promoting factors. Based on a molecular understanding, this review summarizes the positive actions of exogenous umbilical cord-derived MSCs on the immature lung and brain and the therapeutic potential of reprogramming resident MSCs. The pathomechanistic understanding of MSC actions from the animal model is complemented by the promising results from the first phase I clinical trials testing allogenic MSC transplantation from umbilical cord blood. Despite all the enthusiasm towards this new therapeutic option, the caveats and outstanding issues have to be critically evaluated before a broad introduction of MSC-based therapies.

Cognitive Outcomes of Children Born Extremely or Very Preterm Since the 1990s and Associated Risk Factors: A Meta-analysis and Meta-regression

Importance

Despite apparent progress in perinatal care, children born extremely or very preterm (EP/VP) remain at high risk for cognitive deficits. Insight into factors contributing to cognitive outcome is key to improve outcomes after EP/VP birth.

Objective

To examine the cognitive abilities of children of EP/VP birth (EP/VP children) and the role of perinatal and demographic risk factors.

Data Sources

PubMed, Web of Science, and PsycINFO were searched without language restriction (last search March 2, 2017). Key search terms included preterm, low birth weight, and intelligence.

Study Selection

Peer-reviewed studies reporting intelligence scores of EP/VP children (<32 weeks of gestation) and full-term controls at age 5 years or older, born in the antenatal corticosteroids and surfactant era, were included. A total of 268 studies met selection criteria, of which 71 covered unique cohorts.

Data Extraction and Synthesis

MOOSE guidelines were followed. Data were independently extracted by 2 researchers. Standardized mean differences in intelligence per study were pooled using random-effects meta-analysis. Heterogeneity in effect size across studies was studied using multivariate, random-effects meta-regression analysis.

Main Outcomes and Measures

Primary outcome was intelligence. Covariates included gestational age, birth weight, birth year, age at assessment, sex, race/ethnicity, socioeconomic status, small for gestational age, intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia (BPD), necrotizing enterocolitis, sepsis, and postnatal corticosteroid use.

Results

The 71 included studies comprised 7752 EP/VP children and 5155 controls. Median gestational age was 28.5 weeks (interquartile range [IQR], 2.4 weeks) and the mean age at assessment ranged from 5.0 to 20.1 years. The median proportion of males was 50.0% (IQR, 8.7%). Preterm children had a 0.86-SD lower IQ compared with controls (95% CI, -0.94 to -0.78, P < .001). Results were heterogeneous across studies (I2 = 74.13; P < .001). This heterogeneity could not be explained by birth year of the cohort. Multivariate meta-regression analysis with backward elimination revealed that BPD explained 65% of the variance in intelligence across studies, with each percent increase in BPD rate across studies associated with a 0.01-SD decrease in IQ (0.15 IQ points) (P < .001).

Conclusions and Relevance

Extremely or very preterm children born in the antenatal corticosteroids and surfactant era show large deficits in intelligence. No improvement in cognitive outcome was observed between 1990 and 2008. These findings emphasize that improving outcomes after EP/VP birth remains a major challenge. Bronchopulmonary dysplasia was found to be a crucial factor for cognitive outcome. Lowering the high incidence of BPD may be key to improving long-term outcomes after EP/VP birth.

Regional microstructural organization of the cerebral cortex is affected by preterm birth

Objectives

To compare regional cerebral cortical microstructural organization between preterm infants at term-equivalent age (TEA) and healthy full-term newborns, and to examine the impact of clinical risk factors on cerebral cortical micro-organization in the preterm cohort.

Study design

We prospectively enrolled very preterm infants (gestational age (GA) at birth<32 weeks; birthweight<1500 g) and healthy full-term controls. Using non-invasive 3T diffusion tensor imaging (DTI) metrics, we quantified regional micro-organization in ten cerebral cortical areas: medial/dorsolateral prefrontal cortex, anterior/posterior cingulate cortex, insula, posterior parietal cortex, motor/somatosensory/auditory/visual cortex. ANCOVA analyses were performed controlling for sex and postmenstrual age at MRI.

Results

We studied 91 preterm infants at TEA and 69 full-term controls. Preterm infants demonstrated significantly higher diffusivity in the prefrontal, parietal, motor, somatosensory, and visual cortices suggesting delayed maturation of these cortical areas. Additionally, postnatal hydrocortisone treatment was related to accelerated microstructural organization in the prefrontal and somatosensory cortices.

Conclusions

Preterm birth alters regional microstructural organization of the cerebral cortex in both neurocognitive brain regions and areas with primary sensory/motor functions. We also report for the first time a potential protective effect of postnatal hydrocortisone administration on cerebral cortical development in preterm infants.

Neonatal corticosteroid therapy affects growth patterns in early infancy

Objective

Although postnatal corticosteroid (CS) therapy has well established beneficial effects on pulmonary function, it may also result in growth restriction during treatment. The course of early childhood growth is believed to predict cardiovascular and metabolic diseases in adulthood. Therefore, we determined the effects of postnatal dexamethasone (DEX) or hydrocortisone (HC) treatment on patterns of postnatal growth until approximately four years of age.

Study design

In an observational cohort study of children born prematurely (<32 weeks of gestation), we compared growth patterns for body weight, height, and head circumference from birth to age four years, of children who received DEX (boys: N = 30, girls: N = 14), HC (boys: N = 33, girls: N = 28) to a reference group that had not received postnatal CSs (boys: N = 52, girls: N = 53) using linear mixed-effects modeling.

Results

Growth velocity curves of CS-treated neonates showed a shift to the right, representing a delay in time. They had decreased absolute growth velocities during and shortly after treatment, followed by an increase in growth velocity thereafter. A shift to the right was also seen for the age at which maximal growth velocity of weight/height was reached in boys and girls. Fractional growth rates of weight, height, and head circumference were generally reduced in the CS-treated groups during the first two months of age, with catch-up growth in the following months. In DEX-treated infants these changes were more pronounced than in HC-treated infants.

Conclusion

These data suggest that postnatal growth patterns of preterm born infants are affected by CS-treatment, more by DEX than by HC. Effects were observed mainly on growth velocities. This observation may have impact on health in later life for those individuals treated with CSs in the neonatal period. A definitive conclusion would require a randomized trial of these therapies.

Effects of intratracheal budesonide during early postnatal life on lung maturity of premature fetal rabbits

AIM

This study aimed to study the effects of intratracheal instillation of budesonide on lung maturity of premature fetal rabbits. The developmental pattern of pulmonary alveoli in rabbits is similar to that in humans.

METHOD

Fetal rabbits were taken out from female rabbits on the 28th day of pregnancy (full term = 31 days) by cesarean section (c-section). The fetal rabbits were divided into four groups: control (normal saline, NS), budesonide (budesonide, BUD), calf pulmonary surfactant for injection (pulmonary surfactant, PS), and calf pulmonary surfactant + budesonide for injection (pulmonary surfactant + budesonide, PS + BUD). All premature rabbits were kept warm after c-section. After 15-min autonomous respiration, a tracheal cannula was implemented for instilling NS, BUD, PS, and PS + BUD. The morphology of lung tissues of premature fetal rabbits was analyzed using optical and electron microscopes. Surfactant protein B (SP-B) mRNA and protein levels in lung tissues were determined using polymerase chain reaction and Western blotting, respectively.

RESULT

Intratracheal instillation of BUD could increase the alveolar area of the fetal rabbits (P < 0.01), decrease the alveolar wall thickness (P < 0.01), and increase the mean density of lamellar bodies (P < 0.05) and SP-B protein levels in type II epithelial cells of pulmonary alveoli (P < 0.05).

CONCLUSION

Intratracheal instillation of BUD during early postnatal life is effective in promoting alveolarization and increasing SP-B expression, the pro-pulmonary maturity of BUD combined with PS is superior to that of BUD or PS alone. However, the long-term effect of BUD on lung development needs further exploration.

Postnatal steroids in extreme preterm infants: Intra-tracheal instillation using surfactant as a vehicle

Chronic Lung Disease (CLD) is a common respiratory morbidity in survivors following extreme preterm birth, and is associated with adverse neurodevelopment in the long term. Besides demographics, multiple risk factors are implicated in the pathogenesis of CLD. However, early lung inflammation appears to be the common pathway that leads to the pathological and clinical changes observed in CLD. Postnatal use of systemic steroids has been successful in reducing the incidence of CLD but resulted in unacceptable adverse neurodevelopmental outcomes. The efficacy of inhaled steroids is not yet established. We review the evidence of tracheal instillation of steroids using surfactant as a lipid vehicle, including published data on drug distribution, in vitro physical studies, and clinical trials in animals and human infants.

[Developmental neurology - networked medicine and new perspectives]

Developmental neurology is one of the major areas of neuropediatrics and is among other things (legally) responsible for monitoring the motor, cognitive and psychosocial development of all infants using standardized monitoring investigations. The special focus is on infants born at risk and/or due to premature birth before 32 weeks of gestation or a birth weight less than 1500 g. Early diagnosis of deviations from normal, age-related development is a prerequisite for early interventions, which may positively influence development and the long-term biopsychosocial prognosis of the patients. This article illustrates the available methods in developmental neurology with a focus on recent developments. Particular attention is paid to the predictive value of general movements (GM). The current development of markerless automated detection of spontaneous movements using conventional depth imaging cameras is demonstrated. Differences in spontaneous movements in infants at the age of 12 weeks are illustrated and discussed exemplified by three patients (healthy versus genetic syndrome versus cerebral palsy).

An evaluation of hydrocortisone dosing for neonatal refractory hypotension

OBJECTIVE

The objective of the study was to compare blood pressure, vasoactive medication requirements and adverse outcomes after administration of high- versus low-dose hydrocortisone (HC) in preterm infants.

STUDY DESIGN

This is a retrospective analysis of 106 infants ⩽28 weeks gestational age with hypotension requiring vasoactive infusions and high-dose (4 mg kg^-1 per day, n=50), low-dose (1 to 3 mg kg^-1 per day, n=20) or no HC (n=36) from 2011 to 2015. Groups were compared by two-tailed t-test or χ², and correlation estimated by multivariable logistic regression.

RESULTS

There were no differences in measured efficacy between the low- and high-dose groups. Infants with pre-treatment cortisol >15 mcg dl^-1 who received HC therapy showed less improvement in vasoactive burden, increased hyperglycemia (P=0.015) and increased death independent of HC dose (odds ratio 26.3, 3.5 to 198.3, P=0.002).

CONCLUSION

These results support using the lowest effective HC dose in preterm infants. In addition, HC therapy should likely be avoided in infants who are not cortisol deficient.

Prevention of bronchopulmonary dysplasia: current strategies

Bronchopulmonary dysplasia (BPD) is one of the few diseases affecting premature infants that have continued to evolve since its first description about half a century ago. The current form of BPD, a more benign and protracted respiratory failure in extremely preterm infants, is in contrast to the original presentation of severe respiratory failure with high mortality in larger premature infants. This new BPD is end result of complex interplay of various antenatal and postnatal factors causing lung injury and subsequent abnormal repair leading to altered alveolar and vascular development. The change in clinical and pathologic picture of BPD over time has resulted in new challenges in developing strategies for its prevention and management. While some of these strategies like Vitamin A supplementation, caffeine and volume targeted ventilation have stood the test of time, others like postnatal steroids are being reexamined with great interest in last few years. It is quite clear that BPD is unlikely to be eliminated unless some miraculous strategy cures prematurity. The future of BPD prevention will probably be a combination of antenatal and postnatal strategies acting on multiple pathways to minimize lung injury and abnormal repair as well as promote normal alveolar and vascular development.

[Does corticosteroid treatment during the pre and postnatal periods affect the neurodevelopmental outcome of premature newborns?]

INTRODUCTION

Glucocorticoids, widely used in the perinatal period, may be associated with adverse neurodevelopmental effects.

OBJECTIVES

To analyze neurodevelopmental outcomes in a cohort of very low birth weight newborns treated with antenatal and/or postnatal corticosteroids.

MATERIALS AND METHODS

This was a prospective cohort study in which we included all very low birth weight babies admitted to the neonatal intensive care unit of a tertiary hospital between 2008 and 2013. We compared the neurodevelopment among very low birth-weight newborns who did not receive prenatal corticosteroid therapy and those who received a complete course (two doses of 12 mg betamethasone) and an incomplete course (one dose), and between those who did not receive postnatal corticosteroid therapy and those who received it (systemic dexamethasone after the first week of life). Motor, neurosensory and cognitive functions, as well as behavior disorders during the first two years of age were evaluated.

RESULTS

A total of 225 very low birth weight newborns were analyzed; 83.6% received prenatal corticosteroid therapy (24% incomplete treatment schedule and 59.6% complete schedule). Only 13.3% received systemic dexamethasone during the postnatal period. Neurological monitoring was performed corticosteroid therapy and more neurological disorders, and no significant differences were found among those who received complete and incomplete courses of prenatal corticosteroid therapy.

CONCLUSION

These results did not demonstrate an association between perinatal corticosteroid therapy and worse neurodevelopmental outcomes in very low birth weight newborns.

Respiratory Support for Very Low Birth Weight Infants Receiving Dexamethasone

OBJECTIVE

To assess how neonatal intensive care units followed the American Academy of Pediatrics guidelines for use of dexamethasone in preterm infants by evaluating respiratory support at the time of dexamethasone administration.

STUDY DESIGN

This is an observational study of infants discharged from one of 290 neonatal intensive care units from 2003 to 2010. The cohort included very low birth weight (<1500 g birth weight) infants born at ≤32 weeks gestational age. The main outcome was respiratory support at time of exposure to dexamethasone. Significant respiratory support was defined as invasive respiratory support (conventional or high-frequency ventilation) with a fraction of inspired oxygen (FiO₂) > 0.3.

RESULTS

Of 81 292 infants; 7093 (9%) received dexamethasone. At the time that dexamethasone was initiated, 4604 (65%) of infants were on significant respiratory support.

CONCLUSIONS

In accordance with the American Academy of Pediatrics recommendations, a majority of infants were on significant respiratory support when receiving dexamethasone, yet a substantial number of infants still received dexamethasone on less than significant respiratory support. Further research on reducing dexamethasone use in premature infants is required to decrease the risk of neurodevelopmental impairment.

A comparison of 7-day versus 10-day course of low-dose dexamethasone for chronically ventilated preterm infants

OBJECTIVE

The objective of the study was to compare the effect of two different dexamethasone regimens on respiratory outcomes of ventilator-dependent preterm infants.

STUDY DESIGN

Retrospective study of ventilated preterm infants <29 weeks gestational age treated with either 7-day or 10-day dexamethasone course. Primary outcome was days to successful extubation. Other outcomes included rate of successful extubation and need for repeat steroid therapy.

RESULTS

Fifty-nine infants were identified; 32 (54%) received 7 days of dexamethasone and 27 (46%) received 10 days of dexamethasone. Both groups had comparable baseline demographics and clinical characteristics. Mean time to successful extubation was similar between the two groups (5.1±2.7 days in 7-day group and 6.0±3.7 days in 10-day group, P=0.42). Successful extubation by end of treatment (56% versus 67%, P=0.44) and need for repeat steroid therapy (47% versus 33%, P=0.43) were also similar.

CONCLUSION

7-day and 10-day course of dexamethasone have comparable efficacy in facilitating extubation of ventilator-dependent preterm infants.

Evidence-Based Neonatal Unit Practices and Determinants of Postnatal Corticosteroid-Use in Preterm Births below 30 Weeks GA in Europe. A Population-Based Cohort Study

Background

Postnatal corticosteroids (PNC) were widely used to treat and prevent bronchopulmonary dysplasia in preterm infants until studies showed increased risk of cerebral palsy and neurodevelopmental impairment. We aimed to describe PNC use in Europe and evaluate the determinants of their use, including neonatal characteristics and adherence to evidence-based practices in neonatal intensive care units (NICUs).

Methods

3917/4096 (95,6%) infants born between 24 and 29 weeks gestational age in 19 regions of 11 European countries of the EPICE cohort we included. We examined neonatal characteristics associated with PNC use. The cohort was divided by tertiles of probability of PNC use determined by logistic regression analysis. We also evaluated the impact of the neonatal unit’s reported adherence to European recommendations for respiratory management and a stated policy of reduced PNC use.

Results

PNC were prescribed for 545/3917 (13.9%) infants (regional range 3.1–49.4%) and for 29.7% of infants in the highest risk tertile (regional range 5.4–72.4%). After adjustment, independent predictors of PNC use were a low gestational age, small for gestational age, male sex, mechanical ventilation, use of non-steroidal anti-inflammatory drugs to treat persistent ductus arteriosus and region. A stated NICU policy reduced PNC use (odds ratio 0.29 [95% CI 0.17; 0.50]).

Conclusion

PNC are frequently used in Europe, but with wide regional variation that was unexplained by neonatal characteristics. Even for infants at highest risk for PNC use, some regions only rarely prescribed PNC. A stated policy of reduced PNC use was associated with observed practice and is recommended.

Effect of perinatal glucocorticoids on vascular health and disease

The benefits of antenatal glucocorticoids are now firmly established in the perinatal management of threatened preterm birth. Postnatal glucocorticoid therapy, however, remains controversial in neonatal medicine, with the need to balance short-term physiological benefits against the potential for long-term adverse consequences. This review focuses on the vascular effects of prenatal and postnatal glucocorticoids, synthesizing data from both experimental animal models and human infants with the goal of better appreciation of the short and long-term effects of these commonly used drugs. Due to their widespread and varied use, improved understanding of the cellular and molecular impact of glucocorticoids is important in guiding current practice and future research.

Neonatal Dexamethasone Treatment Exacerbates Hypoxia/Ischemia-Induced White Matter Injury

Dexamethasone, a synthetic glucocorticoid, has been widely used to prevent or ameliorate morbidity of chronic lung disease in preterm infants with respiratory distress syndrome. Despite its beneficial effect on neonatal lung function, growing concern has arisen about adverse effects of this clinical practice on fetal brain development. We demonstrated previously that neonatal dexamethasone (DEX) treatment may render the newborn brain to be more vulnerable to hypoxia/ischemia (HI)-induced gray matter injury. Here, we examined whether neonatal DEX treatment may also affect the extent of HI-induced subcortical white matter (WM) injury in the developing rat brain. Using a HI model of premature brain injury, we demonstrated that a 3-day tapering course (0.5, 0.3, and 0.1 mg/kg) of DEX treatment in rat pups on postnatal days 1-3 (P1-3) significantly reduced the number of all stages of the oligodendroglial lineage cells on P7 and exacerbated HI-induced WM injury. Neonatal DEX treatment also enhanced HI-induced oligodendroglial apoptosis and astrocyte activation in the developing WM on P14. Likewise, HI-induced reductions in myelin thickness, axon caliber, and function during WM development were exacerbated by neonatal DEX treatment. Furthermore, neonatal DEX treatment further aggravated HI-induced motor deficits as assessed in the rotarod test. We also found that the administration of β-lactam antibiotic ceftriaxone increased glutamate transporter-1 protein expression and significantly reduced HI-induced WM injury in neonatal DEX-treated rats. These results suggest that neonatal DEX treatment may lead the developing brain to be more vulnerable to subsequent HI-induced WM injury, which can be ameliorated by ceftriaxone administration.

Effects of antenatal glucocorticoids on the developing brain

Glucocorticoids (GCs) regulate distinct physiological processes in the developing fetus, in particular accelerating organ maturation that enables the fetus to survive outside the womb. In preterm birth, the developing fetus does not receive sufficient exposure to endogenous GCs in utero for proper organ development predisposing the neonate to complications including intraventricular hemorrhage, respiratory distress syndrome (RDS) and necrotizing enterocolitis (NEC). Synthetic GCs (sGCs) have proven useful in the prevention of these complications since they are able to promote the rapid maturation of underdeveloped organs present in the fetus. While these drugs have proven to be clinically effective in the prevention of IVH, RDS and NEC, they may also trigger adverse developmental side effects. This review will examine the current clinical use of antenatal sGC therapy in preterm birth, their placental metabolism, and their effects on the developing brain.

Prevention and management of bronchopulmonary dysplasia: Lessons learned from the neonatal research network

Despite remarkable improvements in survival of extremely premature infants, the burden of BPD among survivors remains a frustrating problem for parents and caregivers. Advances, such as antenatal steroids and surfactant replacement, which have dramatically improved survival, have not reduced BPD among survivors. Other advances that have significantly improved the combined outcome of death or BPD, such as vitamin A and avoidance of mechanical ventilation, have had smaller magnitude effects on the outcome of BPD alone. Postnatal steroids have a clear beneficial effect on BPD, but the optimal preparation, dose, and timing for maximizing benefit and minimizing harm have yet to be determined. This persistent burden of BPD among the most immature survivors remains a challenge for the NRN and other researchers in neonatal medicine.

Respiratory management of extremely low birth weight infants: survey of neonatal specialists

BACKGROUND

To investigate strategies used for the management of respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) in extremely low birth weight (ELBW) infants.

METHODS

A survey of neonatal specialists working in US academic institutions with fellowship training programs.

RESULTS

Eighty percent (72/89) of the identified academic institutions had at least one physician who responded to the survey. Among respondents, 85% (171/201) agreed or strongly agreed to use continuous positive airway pressure (CPAP) initially for the management of RDS, and the majority agreed or strongly agreed to use a fraction of inspired oxygen (FiO2) ≥0.4 and a mean airway pressure (MAP) ≥10 cm H2O as a criteria for surfactant therapy; and 73% (146/200) sometimes or always used caffeine to prevent BPD. Only 25% (50/202) sometimes or almost always used steroids to prevent or treat BPD. Identified indications to use steroids were 3 or more extubation failures or inability to extubate beyond 8 weeks of age.

CONCLUSIONS

Variability in treatment strategies of ELBW is common among neonatal specialists. However, the majority of the respondents agreed or strongly agreed to use early CPAP for the management of RDS, consider a FiO2 ≥0.4 and a MAP ≥10 cm H2O as criteria for surfactant therapy, and sometimes or almost always used caffeine to prevent BPD. Steroids continue to have a role in the management of BPD in infants who are difficult to extubate.

Inhibition of Hippocampal Regeneration by Adjuvant Dexamethasone in Experimental Infant Rat Pneumococcal Meningitis

Pneumococcal meningitis (PM) causes neurological sequelae in up to half of surviving patients. Neuronal damage associated with poor outcome is largely mediated by the inflammatory host response. Dexamethasone (DXM) is used as an adjuvant therapy in adult PM, but its efficacy in the treatment of pneumococcal meningitis in children is controversially discussed. While DXM has previously been shown to enhance hippocampal apoptosis in experimental PM, its impact on hippocampal cell proliferation is not known. This study investigated the impact of DXM on hippocampal proliferation in infant rat PM. Eleven-day-old nursing Wistar rats (n = 90) were intracisternally infected with Streptococcus pneumoniae to induce experimental meningitis. Treatment with DXM or vehicle was started 18 h after infection, concomitantly with antibiotics (ceftriaxone 100 mg/kg of body weight twice a day [b.i.d.]). Clinical parameters were monitored, and the amount of cells with proliferating activity was assessed using in vivo incorporation of bromodeoxyuridine (BrdU) and an in vitro neurosphere culture system at 3 and 4 d postinfection. DXM significantly worsened weight loss and survival. Density of BrdU-positive cells, as an index of cells with proliferating activity, was significantly lower in DXM-treated animals compared to vehicle controls (P < 0.0001). In parallel, DXM reduced neurosphere formation as an index for stem/progenitor cell density compared to vehicle treatment (P = 0.01). Our findings provide clear evidence that DXM exerts an antiproliferative effect on the hippocampus in infant rat PM. We conclude that an impairment of regenerative hippocampal capacity should be taken into account when considering adjuvant DXM in the therapeutic regimen for PM in children.

Birth Prevalence of Cerebral Palsy: A Population-Based Study

OBJECTIVE

Population-based data in the United States on trends in cerebral palsy (CP) birth prevalence are limited. The objective of this study was to examine trends in the birth prevalence of congenital spastic CP by birth weight, gestational age, and race/ethnicity in a heterogeneous US metropolitan area.

METHODS

Children with CP were identified by a population-based surveillance system for developmental disabilities (DDs). Children with CP were included if they were born in metropolitan Atlanta, Georgia, from 1985 to 2002, resided there at age 8 years, and did not have a postneonatal etiology (n = 766). Birth weight, gestational age, and race/ethnicity subanalyses were restricted to children with spastic CP (n = 640). Trends were examined by CP subtype, gender, race/ethnicity, co-occurring DDs, birth weight, and gestational age.

RESULTS

Birth prevalence of spastic CP per 1000 1-year survivors was stable from 1985 to 2002 (1.9 in 1985 to 1.8 in 2002; 0.3% annual average prevalence; 95% confidence interval [CI] -1.1 to 1.8). Whereas no significant trends were observed by gender, subtype, birth weight, or gestational age overall, CP prevalence with co-occurring moderate to severe intellectual disability significantly decreased (-2.6% [95% CI -4.3 to -0.8]). Racial disparities persisted over time between non-Hispanic black and non-Hispanic white children (prevalence ratio 1.8 [95% CI 1.5 to 2.1]). Different patterns emerged for non-Hispanic white and non-Hispanic black children by birth weight and gestational age.

CONCLUSIONS

Given improvements in neonatal survival, evidence of stability of CP prevalence is encouraging. Yet lack of overall decreases supports continued monitoring of trends and increased research and prevention efforts. Racial/ethnic disparities, in particular, warrant further study.

Evidence-Based Pharmacologic Therapies for Prevention of Bronchopulmonary Dysplasia: Application of the Grading of Recommendations Assessment, Development, and Evaluation Methodology

Bronchopulmonary dysplasia (BPD) is the most common chronic complication of extreme preterm birth. The authors applied the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to pharmacologic therapies found to prevent BPD. Caffeine and vitamin A are the only medications shown in high-quality studies to prevent BPD without the risk of clinically important adverse effects. Dexamethasone is effective for the prevention of BPD; but for many infants, the increased risks of hypertrophic cardiomyopathy, gastrointestinal perforation, and cerebral palsy outweigh this benefit. Several medications are currently under investigation for the prevention of BPD, but few are novel agents.

Fetal human airway smooth muscle cell production of leukocyte chemoattractants is differentially regulated by fluticasone

BACKGROUND

Adult human airway smooth muscle (ASM) produce cytokines involved in recruitment and survival of leukocytes within airway walls. Cytokine generation by adult ASM is glucocorticoid-sensitive. Whether developing lung ASM produces cytokines in a glucocorticoid-sensitive fashion is unknown.

METHODS

Cultured fetal human ASM cells stimulated with TNF-α (0-20 ng/ml) were incubated with TNF-α receptor-blocking antibodies, fluticasone (1 and 100 nm), or vehicle. Supernatants and cells were assayed for the production of CCL5, CXCL10, and CXCL8 mRNA and protein and glucocorticoid receptor phosphorylation.

RESULTS

CCL5, CXCL10, and CXCL8 mRNA and protein production by fetal ASM cell was significantly and dose-dependently following TNF-α treatment. Cytokine mRNA and protein production were effectively blocked by TNF-α R1 and R2 receptor neutralizing antibodies but variably inhibited by fluticasone. TNF-α-induced TNF-R1 and R2 receptor mRNA expression was only partially attenuated by fluticasone. Glucocorticoid receptor phosphorylation at serine (Ser) 211 but not at Ser 226 was enhanced by fluticasone.

CONCLUSION

Production of CCL5, CXCL10, and CXCL8 by fetal ASM appears to involve pathways that are both qualitatively and mechanistically distinct to those described for adult ASM. The findings imply developing ASM has potential to recruit leukocyte into airways and, therefore, of relevance to childhood airway diseases.

New means to assess neonatal inflammatory brain injury

Preterm infants are especially vulnerable to infection-induced white matter injury, associated with cerebral palsy, cognitive and psychomotor impairment, and other adverse neurological outcomes. The etiology of such lesions is complex and multifactorial. Furthermore, timing and length of exposure to infection also influence neurodevelopmental outcomes. Different mechanisms have been posited to mediate the observed brain injury including microglial activation followed by subsequent release of pro-inflammatory species, glutamate-induced excitotoxicity, and vulnerability of developing oligodendrocytes to cerebral insults. The prevalence of such neurological impairments requires an urgent need for early detection and effective neuroprotective strategies. Accordingly, noninvasive methods of monitoring disease progression and therapy effectiveness are essential. While diagnostic tools using biomarkers from bodily fluids may provide useful information regarding potential risks of developing neurological diseases, the use of magnetic resonance imaging/spectroscopy has emerged as a promising candidate for such purpose. Various pharmacological agents have demonstrated protective effects in the immature brain in animal models; however, few studies have progressed to clinical trials with promising results.

Dexamethasone but not the equivalent doses of hydrocortisone induces neurotoxicity in neonatal rat brain

BACKGROUND

The use of dexamethasone (Dex) in premature infants to treat or prevent chronic lung disease adversely affects neurodevelopment. Recent clinical studies suggest that hydrocortisone (HC) is a safer alternative to Dex. We compared the effects of Dex and HC on neurotoxicity in newborn rats.

METHODS

Rat pups of a neurodevelopmental stage equivalent to premature human neonates were administered Dex or HC either as a single dose on postnatal day (PD) 6, repeated doses on PD 4 to 6 or tapering doses at PD 3 to 6 by i.p. injection. Brain weight, caspase-3 activity, and apoptotic cells were measured at PD 7; learning capability, memory, and motor function were measured at juvenile age.

RESULTS

Dex decreased both body and brain weight gain, while HC did not. Tapering and repeated doses of Dex increased caspase-3 activity, cleaved caspase-3 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells but HC, except at high doses, did not. Dex impaired learning and memory capability at juvenile age, while the rats exposed to HC showed normal cognitive behavior.

CONCLUSION

HC is probably safer to use than Dex in the immediate postnatal period in neonatal rats. Cautious extrapolation of these findings to human premature infants is required.

Dexamethasone Treatment of Newborn Rats Decreases Cardiomyocyte Endowment in the Developing Heart through Epigenetic Modifications

The potential adverse effect of synthetic glucocorticoid, dexamethasone therapy on the developing heart remains unknown. The present study investigated the effects of dexamethasone on cardiomyocyte proliferation and binucleation in the developing heart of newborn rats and evaluated DNA methylation as a potential mechanism. Dexamethasone was administered intraperitoneally in a three day tapered dose on postnatal day 1 (P1), 2 and 3 to rat pups in the absence or presence of a glucocorticoid receptor antagonist Ru486, given 30 minutes prior to dexamethasone. Cardiomyocytes from P4, P7 or P14 animals were analyzed for proliferation, binucleation and cell number. Dexamethasone treatment significantly increased the percentage of binucleated cardiomyocytes in the hearts of P4 pups, decreased myocyte proliferation in P4 and P7 pups, reduced cardiomyocyte number and increased the heart to body weight ratio in P14 pups. Ru486 abrogated the effects of dexamethasone. In addition, 5-aza-2'-deoxycytidine (5-AZA) blocked the effects of dexamethasone on binucleation in P4 animals and proliferation at P7, leading to recovered cardiomyocyte number in P14 hearts. 5-AZA alone promoted cardiomyocyte proliferation at P7 and resulted in a higher number of cardiomyocytes in P14 hearts. Dexamethasone significantly decreased cyclin D2, but not p27 expression in P4 hearts. 5-AZA inhibited global DNA methylation and blocked dexamethasone-mediated down-regulation of cyclin D2 in the heart of P4 pups. The findings suggest that dexamethasone acting on glucocorticoid receptors inhibits proliferation and stimulates premature terminal differentiation of cardiomyocytes in the developing heart via increased DNA methylation in a gene specific manner.

Neonatal glucocorticoid treatment: long-term effects on the hypothalamus-pituitary-adrenal axis, immune system, and problem behavior in 14-17 year old adolescents

Neonatal glucocorticoid (GC) treatment is used to prevent bronchopulmonary dysplasia (BPD) in prematurely born babies. In the 1990s, treatment regimens with relatively high doses of dexamethasone (DEX) were common. As an alternative, hydrocortisone (HC) was used. Earlier, we compared long-term effects of both GCs in children aged 7-10 and detected adverse effects of neonatal DEX treatment, but not of HC, on a range of outcomes. The aim of the current cohort study was to investigate whether long-term effects of neonatal DEX were maintained and whether effects of HC remained absent at adolescent age (14-17years). We compared 71 DEX-treated and 67 HC-treated adolescents. In addition, 71 adolescents who were not neonatally treated with GCs participated. All were born <32weeks of gestation. DEX-treated girls showed increased adrenocorticotropic hormone (ACTH) and cortisol responses in the Trier Social Stress Test. The cortisol awakening response was lower in HC-treated participants compared to untreated participants. Negative feedback function of the HPA-axis in the dexamethasone suppression test did not differ between groups. In contrast to our observations at the age of 7-10years, we did not observe group differences in mitogen-induced cytokine production at the age of 14-17years. DEX-treated girls showed more social problems and anxious/depressed behavior than HC-treated girls. Untreated girls showed more problem behavior as well. In conclusion, our results suggest that, especially in girls, neonatal DEX has a programming effect on the HPA-axis and on the ability to adjust to the environment. The loss of group differences on immune system measures indicate that potentially negative effects detected at a younger age subsided.

Neurodevelopmental impact of hydrocortisone exposure in extremely low birth weight infants: outcomes at 1 and 2 years

OBJECTIVE

Postnatal steroids are used in neonatal intensive care units despite known side effects. Hydrocortisone (HC) use persists as it is believed to have less deleterious effects on neurodevelopmental (ND) outcome compared to other steroids. The literature is sparse with respect to the ND impact of HC use in recent years. Hence, we sought to examine the effect of HC use on ND outcome in a contemporary cohort of extremely low birth weight (ELBW) infants.

STUDY DESIGN

A total of 175 ELBW infants (86 HC exposed, 89 steroid naive) born in 2008 to 2010 were compared for mortality, morbidity and ND outcome at 8 and 20 months corrected age. Outcome measures included neurologic exam and results of the Bayley Scales of Infant and Toddler Development-III (BSITD-III). Multiple regression analyses adjusted for the effect of other risk factors on outcome.

RESULT

Overall, 65 (75%) of the HC and 74 (83%) of the no-HC groups survived to discharge. HC infants were smaller (mean birth weight (BW) 719 ± 127 g vs 837 ± 99 g) and of lower gestational age (GA) (mean GA 26.0 ± 1.7 weeks vs 27.5 ± 1.8 weeks) compared to the no-HC group. Patients in the HC group were more likely to be a multiple, have a severely abnormal head ultrasound, bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis and receive treatment for patent ductus arteriosus and hypotension than those in the no-HC group. Of the HC group, the mean age at treatment was 20 ± 19 days, mean duration of treatment 49 ± 37 days. At 8 months, the HC group had lower mean motor (87 ± 18 vs 95 ± 15, P = 0.028) and fine motor (9 ± 2.9 vs 10.5 ± 2.6, P = 0.005) and higher rate of subnormal motor (44 vs 15%, P = 0.002) and fine motor scores (24 vs 6.5%, P = 0.017). In regression analyses, HC exposure >7 days was significantly related to worse outcome on fine motor scores at 8 months while cumulative days of HC exposure was a predictor of worse outcome on language at 8 months and motor outcome at 20 months. Each additional day of HC exposure increased the odds of subnormal receptive and expressive language in the first year of life by 4 and 2%, respectively, and increased odds of subnormal motor function by 2% in the 2nd year of life.

CONCLUSION

HC exposure for >7 days is associated with worse performance in fine motor skills in the first year of life, while cumulative HC exposure negatively impacts receptive and expressive language skills in the first year and motor skills in the second year of life after adjusting for neonatal and social risk factors.

Postnatal glucocorticoid-induced hypomyelination, gliosis, and neurologic deficits are dose-dependent, preparation-specific, and reversible

Postnatal glucocorticoids (GCs) are widely used in the prevention of chronic lung disease in premature infants. Their pharmacologic use is associated with neurodevelopmental delay and cerebral palsy. However, the effect of GC dose and preparation (dexamethasone versus betamethasone) on short and long-term neurological outcomes remains undetermined, and the mechanisms of GC-induced brain injury are unclear. We hypothesized that postnatal GC would induce hypomyelination and motor impairment in a preparation- and dose-specific manner, and that GC receptor (GR) inhibition might restore myelination and neurological function in GC-treated animals. Additionally, GC-induced hypomyelination and neurological deficit might be transient. To test our hypotheses, we treated prematurely delivered rabbit pups with high (0.5mg/kg/day) or low (0.2mg/kg/day) doses of dexamethasone or betamethasone. Myelin basic protein (MBP), oligodendrocyte proliferation and maturation, astrocytes, transcriptomic profile, and neurobehavioral functions were evaluated. We found that high-dose GC treatment, but not low-dose, reduced MBP expression and impaired motor function at postnatal day 14. High-dose dexamethasone induced astrogliosis, betamethasone did not. Mifepristone, a GR antagonist, reversed dexamethasone-induced myelination, but not astrogliosis. Both GCs inhibited oligodendrocyte proliferation and maturation. Moreover, high-dose dexamethasone altered genes associated with myelination, cell-cycle, GR, and mitogen-activated protein kinase. Importantly, GC-induced hypomyelination, gliosis, and motor-deficit, observed at day 14, completely recovered by day 21. Hence, high-dose, but not low-dose, postnatal GC causes reversible reductions in myelination and motor functions. GC treatment induces hypomyelination by GR-dependent genomic mechanisms, but astrogliosis by non-genomic mechanisms. GC-induced motor impairment and neurodevelopmental delay might be transient and recover spontaneously in premature infants.

Effect of dexamethasone on intelligence and hearing in preterm infants: a meta-analysis

OBJECTIVE

A meta-analysis of published randomized controlled trials investigating the long-term effect of dexamethasone on the nervous system of preterm infants.

DATA SOURCES

Online literature retrieval was conducted using The Cochrane Library (from January 1993 to June 2013), EMBASE (from January 1980 to June 2013), MEDLINE (from January 1963 to June 2013), OVID (from January 1993 to June 2013), Springer (from January 1994 to June 2013) and Chinese Academic Journal Full-text Database (from January 1994 to June 2013). Key words were preterm infants and dexamethasone in English and Chinese.

STUDY SELECTION

Selected studies were randomized controlled trials assessing the effect of intravenous dexamethasone in preterm infants. The quality of the included papers was evaluated and those without the development of the nervous system and animal experiments were excluded. Quality assessment was performed through bias risk evaluation in accordance with Cochrane Handbook 5.1.0 software in the Cochrane Collaboration. The homogeneous studies were analyzed and compared using Revman 5.2.6 software, and then effect model was selected and analyzed. Those papers failed to be included in the meta-analysis were subjected to descriptive analysis.

MAIN OUTCOME MEASURES

Nervous system injury in preterm infants.

RESULTS

Ten randomized controlled trials were screened, involving 1,038 subjects. Among them 512 cases received dexamethasone treatment while 526 cases served as placebo control group and blank control group. Meta-analysis results showed that the incidence of cerebral palsy, visual impairment and hearing loss in preterm infants after dexamethasone treatment within 7 days after birth was similar to that in the control group (RR = 1.47, 95%CI: 0.97-2.21; RR = 1.46, 95%CI: 0.97-2.20; RR = 0.80, 95%CI: 0.54-1.18; P > 0.05), but intelligence quotient was significantly decreased compared with the control group (MD = -3.55, 95%CI: -6.59 to -0.51; P = 0.02). Preterm infants treated with dexamethasone 7 days after birth demonstrated an incidence of cerebral palsy and visual impairment, and changes in intelligence quotient similar to those in the control group (RR = 1.26, 95%CI: 0.89-1.79; RR = 1.37, 95%CI: 0.73-2.59; RR = 0.53, 95%CI: 0.32-0.89; RR = 1.66, 95%CI: -4.7 to 8.01; P > 0.05). However, the incidence of hearing loss was significantly increased compared with that in the control group (RR = 0.53, 95%CI: 0.32-0.89; P = 0.02).

CONCLUSION

Dexamethasone may affect the intelligence of preterm infants in the early stages after birth, but may lead to hearing impairment at later stages after birth. More reliable conclusions should be made through large-size, multi-center, well-designed randomized controlled trials.

Sensorineural hearing loss in very low birth weight infants with histological chorioamnionitis

OBJECTIVE

Histological chorioamnionitis (HCAM) has been associated with inflammatory diseases of preterm infants. Recently we have observed that it increased the risk of speech delay and hearing loss. So the aim of this study was to evaluate the relationship between sensorineural hearing loss (SNHL) of VLBW infants and HCAM.

METHODS

We performed an observational study on VLBW infants admitted to the NICU of Padua. Each patient with HCAM was matched with one control without HCAM. All infants underwent hearing screening before discharge by means of automated transient-evoked otoacustic emissions and automated auditory brainstem responses, which were repeated at 3 and 6 months of age with tympanometry measurement. Incidence of SNHL at 6 months of age was compared in the 2 groups and risk factors for hearing loss were studied.

RESULTS

Two of 77 (2.6%) newborns with HCAM e 6/73 (8.2%) without it presented SNHL at 6 months of corrected age (p = 0.16). Multivariable logistic regression analysis identified surgical ligation of patent ductus arteriosus (PDA) as independent predictors of SNHL (OR: 5.75, 95% CI 1.34-24.84, p = 0.02), whereas the effect of HCAM on SNHL was only near to statistical significance level.

CONCLUSIONS

Surgical ligation of PDA is associated with an increased risk of SNHL in VLBW infants, regardless of HCAM.

Cranial index of children with normal and abnormal brain development in Sokoto, Nigeria: A comparative study

Background:

Abnormal brain development due to neurodevelopmental disorders in children has always been an important concern, but yet has to be considered as a significant public health problem, especially in the low- and middle-income countries including Nigeria.

Aims:

The aim of this study is to determine whether abnormal brain development in the form of neurodevelopmental disorders causes any deviation in the cranial index of affected children.

Materials and Methods:

This is a comparative study on the head length, head width, and cranial index of 112 children (72 males and 40 females) diagnosed with at least one abnormal problem in brain development, in the form of a neurodevelopmental disorder (NDD), in comparison with that of 218 normal growing children without any form of NDD (121 males and 97 females), aged 0-18 years old seen at the Usmanu Danfodiyo University Teaching Hospital, Sokoto, over a period of six months, June to December, 2012. The head length and head width of the children was measured using standard anatomical landmarks and cranial index calculated. The data obtained was entered into the Microsoft excel worksheet and analyzed using SPSS version 17.

Results:

The mean Cephalic Index for normal growing children with normal brain development was 79.82 ± 3.35 and that of the children with abnormal brain development was 77.78 ± 2.95 and the difference between the two groups was not statistically significant (P > 0.05).

Conclusion:

It can be deduced from this present study that the cranial index does not change in children with neurodevelopmental disorders.

Trends in the prevalence of cerebral palsy among very preterm infants (<31 weeks' gestational age)

BACKGROUND

The birth prevalence of cerebral palsy varies over time among very preterm infants, and the reasons are poorly understood.

OBJECTIVE

To describe the variation in the prevalence of cerebral palsy among very preterm infants over time, and to relate these differences to other maternal or neonatal factors.

METHODS

A population-based cohort of very preterm infants was evaluated over a 20-year period (1988 to 2007) divided into four equal epochs.

RESULTS

The prevalence of cerebral palsy peaked in the third epoch (1998 to 2002) while mortality rate peaked in the second epoch (1993 to 1997). Maternal anemia, tocolytic use and neonatal need for home oxygen were highest in the third epoch.

CONCLUSIONS

Lower mortality rates did not correlate well with the prevalence of cerebral palsy. Maternal risk factors, anemia and tocolytic use, and the newborn need for home oxygen were highest during the same epoch as the peak prevalence of cerebral palsy.