Neuromotor outcomes in infants with bronchopulmonary dysplasia

Severity of bronchopulmonary dysplasia and characteristics of neuro-motor development prior to acquisition of independent walking in very preterm and/or very low-birth-weight infants: A retrospective cohort study in a children's medical centre in Japan

OBJECTIVE

This study aimed to determine the effect of bronchopulmonary dysplasia (BPD) and its severity on neurological examination at equivalent to full term and the development of gross motor skills prior to the acquisition of independent walking in very preterm and/or very low-birth-weight (VLBW) infants.

METHODS

This study was a retrospective cohort study. Participants were very preterm and/or VLBW infants who were admitted to a neonatal intensive care unit at a children's hospital in Japan between 2017 and 2021. Clinical, demographic, and outcome variables were retrospectively extracted from medical records. The main outcome measures were the Hammersmith Neonatal Neurological Examination (HNNE) score, a neurological examination at the equivalent of full term, and the age at acquisition of each gross motor skill.

RESULTS

In total, 123 infants were included, of whom 62 did not have BPD, 23 had mild BPD, 25 had moderate BPD, and 13 had severe BPD. No significant differences were observed between groups in the neurological examination results for either the total or categorical HNNE scores. For gross motor skills, the results of hierarchical multiple regression analyses adjusted for confounding factors showed that severe BPD remained a factor that delayed the acquisition of most gross motor milestones, even after changing the models. The unstandardised coefficients (beta) restored to the exponent ranged from 1.16 to 1.32 for all models.

CONCLUSIONS

Clinicians involved in the follow-up of very preterm and/or VLBW infants should monitor and support the development of infants with severe BPD from the early postnatal period.

Lung ultrasound in early prediction of bronchopulmonary dysplasia in pre-term babies

PURPOSE

Bronchopulmonary dysplasia (BPD) is a respiratory morbidity related to prematurity. Early prediction of BPD allows the selection of patients who would benefit from new therapies. Lung ultrasound (LUS) is a non-invasive diagnostic tool that has proven to be reliable for many neonatal diseases recently. The study aimed to detect the role of LUS in predicting BPD at days 7 and 14 of life in preterm babies.

METHODS

This was a prospective cohort study that included 95 preterm babies ≤ 34 weeks. Lung ultrasounds were performed on days 7 and 14 of life.

RESULTS

The mean gestational age of the studied neonates was 30.25 ± 2.21 weeks. The mean birth weight was 1347.66 ± 432.14 gm. Patients who developed BPD had statistically significantly higher LUS scores on both days 7 and 14 of life. At first examination, a LUS score > 8 showed a sensitivity of 83.33% and a specificity of 60.87%, whereas at follow-up, a LUS score > 8 showed a sensitivity of 76.39% and a specificity of 82.61%. The multivariate logistic regression analysis shows that the most important factors associated with BPD were gestational age ≤ 30 weeks, LUS score at first examination > 8, platelets ≤ 245 × 109/L, segment neutrophils ≤ 42%, and CRP > 5 mg/l.

CONCLUSIONS

The LUS score predicts BPD at 7 and 14 days of life. LUS scores increased with increasing BPD severity. LUS score > 8 was an independent factor in the prediction of BPD.

Infants with neonatal Chronic Lung Disease are associated with delayed auditory conduction in the rostral brainstem after term

AIMS

Very Low Birthweight (VLBW) infants with neonatal Chronic Lung Disease (CLD) have been found to have functional impairment of the brainstem auditory pathway at term. This study investigated the functional status of the brainstem auditory pathway in VLBW infants with CLD after term for any abnormality.

METHODS

Fifty-two VLBW infants were recruited at 50 weeks of Postconceptional Age: 25 with neonatal CLD and 27 without CLD. None had any other major complications to minimize confounding effects. Brainstem Auditory Evoked Responses were studied at 21‒91/s click rates.

RESULTS

Compared with those without CLD, VLBW infants with CLD had relatively shorter latencies of BAER waves I and III, associated with a slightly lower BAER threshold. Wave V latency and I‒V interpeak interval did not differ significantly between the two groups of infants. The I‒III interval in infants with CLD was shorter than in those without CLD at 91/s clicks. However, the III‒V interval was significantly longer than in those without CLD at all click rates (all p < 0.05). There were no significant differences in the amplitudes of BAER wave components between the two groups of infants.

CONCLUSIONS

The main BAER abnormality in VLBW infants with CLD was a prolonged III‒V interval. Auditory conduction is delayed or impaired at more central regions of the brainstem in CLD infants. After term central auditory function is adversely affected by neonatal CLD. Monitoring post-term change is required to provide valuable information for post-term care of CLD infants.

Modeling gross motor developmental curves of extremely and very preterm infants using the AIMS home-video method

BACKGROUND

Motor development is one of the first signals to identify whether an infant is developing well. For very preterm (VPT) infants without severe perinatal complications, little is known about their motor developmental curves.

AIMS

Explore gross motor developmental curves from 3 until 18 months corrected age (CA) of VPT infants, and related factors. Explore whether separate profiles can be distinguished and compare these to profiles of Dutch term-born infants.

STUDY DESIGN

Prospective cohort study with parents repeatedly recording their infant, using the Alberta Infant Motor Scale (AIMS) home-video method, from 3 to 18 months CA.

SUBJECTS

Forty-two Dutch infants born ≤32.0 weeks gestational age and/or with a birthweight (BW) of <1500 g without severe perinatal complications.

OUTCOME MEASURES

Gross motor development measured with the AIMS.

RESULTS

In total 208 assessments were analyzed, with 27 infants ≥five assessments, 12 with <four, and three with one assessment. Sigmoid-shaped gross motor curves show unidirectional growth and variability. No infant or parental factors significantly influenced motor development, although a trend was seen for the model where lower BW, five-minute Apgar score <7, and Dutch native-speaking parents were associated with slower motor development. Three motor developmental profiles of VPT infants were identified, early developers, gradual developers, and late bloomers, which until 12 months CA are comparable in shape and speed to profiles of Dutch term-born infants.

CONCLUSIONS

VPT infants show great intra- and interindividual variability in gross motor development, with three motor profiles being distinguished. From 12 months CA onwards, VPT infants appear to develop at a slower pace. With some caution, classifying infants into motor developmental profiles may assist clinical decision-making.

Postnatal abnormality in brainstem neural conduction in neonatal bronchopulmonary dysplasia survivors

OBJECTIVE

To investigate postnatal neural conduction in the auditory brainstem in neonatal bronchopulmonary dysplasia (BPD) survivors.

METHODS

Thirty-two very preterm BPD survivors were studied at 57-58 weeks of postconceptional age. Brainstem auditory-evoked response was studied using maximum length sequence. Wave latencies and intervals were analyzed in detail. The controls were 37 normal term infants and 35 very preterm non-BPD infants.

RESULTS

Compared with normal term controls, BPD survivors showed significantly shortened I-III interval but significantly prolonged III-V interval and greater III-V/I-III interval ratio. Compared with very preterm non-BPD controls, BPD survivors showed a significant shortening in waves III latency and I-III interval, moderate prolonged III-V interval, and significantly greater III-V/I-III interval ratio. These differences were generally similar at all click rates used. The slopes of latency- and interval-click rate functions in BPD survivors did not differ significantly from the two control groups.

CONCLUSIONS

Brainstem neural conduction in BPD survivors differed from normal term and age-matched non-BPD infants; neural maturation is accelerated in caudal brainstem regions but delayed in rostral regions. Neonatal BPD survivors are associated with differential maturation in neural conduction at caudal and rostral brainstem regions, which may constitute an important risk for postnatal neurodevelopment in BPD survivors.

IMPACT

We found that brainstem neural conduction at PCA 57-58 weeks in neonatal BPD survivors differs from normal term and age-matched non-BPD infants. No major differences were found between normal term and very preterm non-BPD infants in brainstem auditory conduction. Neural conduction in BPD survivors is accelerated in caudal brainstem regions but delayed in rostral regions. Neonatal BPD survivors are associated with differential maturation in neural conduction at caudal and rostral brainstem regions. The abnormality may constitute an important risk for postnatal neurodevelopment in BPD survivors.

Early motor development in infants with moderate or severe bronchopulmonary dysplasia

BACKGROUND

Timely development of early motor skills is essential for later skill development in multiple domains. Infants with severe bronchopulmonary dysplasia (BPD) have significant risk for developmental delays. Early motor skill development in this population has not been described. The aim of the present study was to characterize motor skill acquisition at 3 and 6 months corrected age (CA) and assess trajectories of skill development over this time period in infants with severe BPD.

METHODS

We performed a single-center, retrospective descriptive study. Motor skills were categorized as present and normal, present but atypical, or absent at 3 and 6 months CA. Logistic regression was used to identify clinical characteristics associated with negative trajectories of skill acquisition.

RESULTS

Data were available for 232 infants and 187 infants at 3 and 6 months CA, respectively. Ten motor skills were present and normal in 5-44%(range) of subjects at 3 months. Nineteen motor skills were present and normal in 1-63%(range) of subjects at 6 months. Significant postural asymmetry was noted throughout the study period. Loss of skills and worsening asymmetries over time were common. Exposure to sedating medications was significantly associated with poor development.

CONCLUSION

We report delays in motor skill acquisition and postural asymmetries in infants with severe BPD at both 3 and 6 months CA. The association between sedating medications and poor development suggests that efforts to limit these exposures may lead to improved development. Targeted interventions to facilitate early motor development may improve outcomes of this high-risk population.

A Systematic Review of the Influence of Continuous Positive Airway Pressure on Fetal and Newborn Animal Models: Suggestions to Improve Neonatal Respiratory Care

INTRODUCTION

Prematurely born infants regularly develop respiratory distress syndrome and require assisted ventilation. Ventilation may injure the premature lung and increase the risk of bronchopulmonary dysplasia. Continuous positive airway pressure (CPAP), a form of noninvasive ventilation, is commonly used in modern neonatology. Limited clinical data are available on the acute and long-term effect of neonatal exposure to CPAP on the lung. Given the restricted clinical data, newborn animal models have been used to study the influence of CPAP on lung structure and function. The findings of animal studies can guide neonatal care and improve the use of CPAP.

METHODS

A systematic review of electronic databases (Medline, Embase, and Cinahl) was performed using the medical subject heading terms, "CPAP" or "continuous positive airway pressure" and "animals" and "newborn." Abstracts were screened for inclusion using predetermined eligibility criteria.

RESULTS

In total, 235 abstracts were identified and screened for inclusion. Of these, 21 papers were included. Large (N = 18) and small (N = 3) animal models investigated the effects of CPAP. Pulmonary outcomes included gas exchange, lung structure and function, surfactant metabolism, lung inflammation and injury, and the effect of intrapulmonary therapy. Compared to mechanical ventilation, CPAP improves lung function, evokes less lung injury, and does not disrupt alveolar development. Surfactant administration combined with CPAP further improves respiratory outcomes. Of concern are findings that CPAP may increase airway reactivity.

DISCUSSION/CONCLUSION

CPAP offers numerous advantages over mechanical ventilation for the immature lung. The combination of CPAP and exogenous surfactant administration offers further pulmonary benefit.

Neurodevelopmental outcomes in very preterm infants: The role of severity of Bronchopulmonary Dysplasia

OBJECTIVE

Bronchopulmonary dysplasia is a chronic respiratory disease that still affects preterm neonates; its association with neurodevelopmental (ND) impairment is already known. Different studies investigated neurodevelopmental outcomes in infants with BPD, often using the old dichotomous definition (BPD vs Non-BPD). This retrospective study aims to evaluate the role of different BPD severity grades on ND outcomes at 24 months of corrected age (CA).

METHODS

All preterm infants born between 2011 and 2015 in the study hospital with a gestational age (GA) ≤ 30 weeks and discharged from our NICU were included and were divided in infants with and without BPD. Infants with BPD were divided into three severity groups as defined by NICHD/NHLBI Workshop in 2001, and were compared to their Non-BPD peers, matching them according to the same GA and year of birth. At 24 months postmenstrual age, we assessed general outcomes (growth and hospital readmissions) and neurodevelopmental outcomes (motor, developmental and sensory outcomes) with a standardized assessment.

RESULTS

We enrolled 89 patients affected by BPD of different grades of severity and a control group of 89 preterm infants without BPD. Infants with Moderate and Severe BPD showed a significantly higher corrected odds ratio (OR) for cognitive impairment compared to controls. Within the group of infants without severe disability (regarding Griffiths' scales), infants with Moderate and Severe BPD as well as infants with Mild BPD showed a significantly higher risk of a lower total Developmental Quotient (DQ) score, even after correction for confounding factors.

CONCLUSIONS

Our study evidenced that not only Severe BPD infants, but also Moderate ones showed a higher risk of overall cognitive impairment at 24 months CA. Within the group of infants without severe disability, also those with Mild BPD had lower Griffiths DQ scores than those without. This would suggest that infants with BPD, regardless of severity, warrant neurodevelopmental follow-up.

Association of Chorioamnionitis With Bronchopulmonary Dysplasia Among Preterm Infants: A Systematic Review, Meta-analysis, and Metaregression

Importance

Bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, remains one of the major and most common complications of very preterm birth. Insight into factors associated with the pathogenesis of BPD is key to improving its prevention and treatment.

Objective

To perform a systematic review, meta-analysis, and metaregression of clinical studies exploring the association between chorioamnionitis (CA) and BPD in preterm infants.

Data Sources

PubMed and Embase were searched without language restriction (last search, October 1, 2018). Key search terms included bronchopulmonary dysplasia, chorioamnionitis, and risk factors.

Study Selection

Included studies were peer-reviewed studies examining preterm (<37 weeks' gestation) or very low-birth-weight (<1500 g) infants and reporting primary data that could be used to measure the association between exposure to CA and the development of BPD.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline was followed. Data were independently extracted by 2 researchers. A random-effects model was used to calculate odds ratios (ORs) and 95% CIs. Heterogeneity in effect size across studies was studied using multivariate, random-effects metaregression analysis.

Main Outcomes and Measures

The primary outcome was BPD, defined as supplemental oxygen requirement on postnatal day 28 (BPD28) or at the postmenstrual age of 36 weeks (BPD36). Covariates considered as potential confounders included differences between CA-exposed and CA-unexposed infants in gestational age, rates of respiratory distress syndrome (RDS), exposure to antenatal corticosteroids, and rates of early- and late-onset sepsis.

Results

A total of 3170 potentially relevant studies were found, of which 158 met the inclusion criteria (244 096 preterm infants, 20 971 CA cases, and 24 335 BPD cases). Meta-analysis showed that CA exposure was significantly associated with BPD28 (65 studies; OR, 2.32; 95% CI, 1.88-2.86; P < .001; heterogeneity: I2 = 84%; P < .001) and BPD36 (108 studies; OR, 1.29; 95% CI, 1.17-1.42; P < .001; heterogeneity: I2 = 63%; P < .001). The association between CA and BPD remained significant for both clinical and histologic CA. In addition, significant differences were found between CA-exposed and CA-unexposed infants in gestational age, birth weight, odds of being small for gestational age, exposure to antenatal corticosteroids, and early- and late-onset sepsis. Chorioamnionitis was not significantly associated with RDS (48 studies; OR, 1.10; 95% CI, 0.92-1.34; P = .24; heterogeneity: I2 = 90%; P < .001), but multivariate metaregression analysis with backward elimination revealed that a model combining the difference in gestational age and the odds of RDS was associated with 64% of the variance in the association between CA and BPD36 across studies.

Conclusions and Relevance

The results of this study confirm that among preterm infants, exposure to CA is associated with a higher risk of developing BPD, but this association may be modulated by gestational age and risk of RDS.

Neurodevelopmental outcomes among extremely premature infants with linear growth restriction

OBJECTIVE

To compare neurodevelopmental outcomes in linear growth-restricted (LGR) infants born <29 weeks with and without weight gain out of proportion to linear growth.

STUDY DESIGN

We compared 2-year neurodevelopmental outcomes between infants with and without LGR and between LGR infants with and without weight gain out of proportion to linear growth. The outcomes were Bayley-III cognitive, motor, and language scores, cerebral palsy, Gross Motor Function Classification System (GMFCS) level ≥ 2, and neurodevelopmental impairment.

RESULT

In total, 1227 infants were analyzed. LGR infants were smaller and less mature at birth, had higher BMI, and had lower Bayley-III language scores (82.3 vs. 85.0, p < 0.05). Among infants with LGR, infants with high BMI had lower language scores compared with those with low-to-normal BMI (80.8 vs. 83.3, p < 0.05), and were more likely to have GMFCS level ≥2 and neurodevelopmental impairment.

CONCLUSION

Among infants with LGR, weight gain out of proportion to linear growth was associated with poorer neurodevelopmental outcomes.

Bronchopulmonary Dysplasia Is Associated with Altered Brain Volumes and White Matter Microstructure in Preterm Infants

BACKGROUND

Bronchopulmonary dysplasia (BPD), an inflammatory disease involving disrupted lung development, is associated with neurodevelopmental outcome in preterm infants.

OBJECTIVE

This study examined the brain volume and white matter (WM) microstructure in preterm infants at term-equivalent age and explored the effects of BPD on brain development.

METHOD

We studied 56 preterm infants (33 with BPD and 23 without BPD) with no evidence of focal abnormalities on conventional magnetic resonance imaging (MRI) at term-equivalent age. Regional brain volumes and diffusion tensor images were examined using advanced segmentation techniques to acquire quantitative volume measurements, and the JHU neonatal template was used for the atlas-based analysis. We compared these infants with 22 healthy term infants of a similar postmenstrual age.

RESULTS

The preterm infants with BPD had smaller cerebral WM (p = 0.005) volumes than the preterm infants without BPD, independent of sex, gestational age, age at MRI scan, and total intracranial volume. Independent of sex, gestational age, and age at MRI scan, the preterm infants with BPD exhibited marked reductions in fractional anisotropy in the corpus callosum (p = 0.006), corticospinal tract (p = 0.003), and superior cerebellar peduncle (p = 0.002) compared with the infants with no BPD, with a significance level of p ≤ 0.008 as a Bonferroni correction for multiple comparisons.

CONCLUSION

Our study highlights the potential impairing influence of BPD on WM and cerebellar development in preterm infants compared with those without BPD at term-equivalent age, suggesting its clinical significance for neurodevelopment in BPD infants.

Postnatal Microstructural Developmental Trajectory of Corpus Callosum Subregions and Relationship to Clinical Factors in Very Preterm Infants

Our objectives were to define the microstructural developmental trajectory of six corpus callosum subregions and identify perinatal clinical factors that influence early development of these subregions in very preterm infants. We performed a longitudinal cohort study of very preterm infants (32 weeks gestational age or younger) (N = 36) who underwent structural MRI and diffusion tensor imaging serially at four time points - before 32, 32, 38, and 52 weeks postmenstrual age. We divided the corpus callosum into six subregions, performed probabilistic tractography, and used linear mixed effects models to evaluate the influence of antecedent clinical factors on its microstructural growth trajectory. The genu and splenium demonstrated the most rapid developmental maturation, exhibited by a steep increase in fractional anisotropy. We identified several factors that favored greater corpus callosum microstructural development, including advancing postmenstrual age, higher birth weight, and college level or higher maternal education. Bronchopulmonary dysplasia, low 5-minute Apgar scores, caffeine therapy/apnea of prematurity and male sex were associated with reduced corpus callosum microstructural integrity/development over the first six months after very preterm birth. We identified a unique postnatal microstructural growth trajectory and associated clinical factor profile for each of the six corpus callosum subregions that is consistent with the heterogeneous functional role of these white matter subregions.

Brainstem auditory abnormality in extremely premature babies and the impact of neonatal bronchopulmonary dysplasia

INTRODUCTION

Extremely premature babies, particularly those who have neonatal bronchopulmonary dysplasia, are at risk of brain damage and neurodevelopmental impairment. This study aimed to examine functional status of the brainstem auditory pathway in extremely premature babies and assess the impact of bronchopulmonary dysplasia on function.

MATERIAL AND METHODS

Brainstem auditory evoked response was studied at term in babies born at ≤27 weeks of gestation with or without neonatal bronchopulmonary dysplasia. The normal controls were term babies without perinatal problems.

RESULTS

Compared with the normal controls, the extremely premature babies showed an elevated response threshold, increased latencies of waves I, III and particularly V. They also showed significantly increased I-V and III-V intervals. The amplitudes of waves I and V were moderately reduced. These abnormalities were clearly more significant in those with bronchopulmonary dysplasia than those without bronchopulmonary dysplasia. A direct comparison between the two groups of extremely premature babies revealed that wave V latency, and I-V and particularly III-V intervals were significantly longer in the babies with bronchopulmonary dysplasia than those without bronchopulmonary dysplasia.

CONCLUSIONS

Extremely premature babies have functional impairment of the brainstem auditory pathway. The impairment is clearly more significant in those with bronchopulmonary dysplasia than those without bronchopulmonary dysplasia. Neonatal bronchopulmonary dysplasia and associated unfavorable conditions are major contributors to brainstem auditory impairment in extremely premature babies.

Bronchopulmonary dysplasia-impact of severity and timing of diagnosis on neurodevelopment of preterm infants: a retrospective cohort study

OBJECTIVE

To assess the contribution of the severity of bronchopulmonary dysplasia (BPD) and the time point of its diagnosis to the prediction of neurodevelopmental impairment (NDI) at corrected age of 2 years in preterm infants.

DESIGN

Retrospective cohort study.

SETTING

Level-III perinatal centre.

PATIENTS AND OUTCOME MEASURES

Infants born in 2000-2013 with gestational age <30 weeks. BPD was defined as FiO₂ >21% for ≥28 days and its severity classified as mild, FiO₂=21%; moderate, FiO₂ <30% and severe, FiO₂ ≥30% and/or positive pressure support. We applied these criteria at two time points: 36 and 40 weeks' postmenstrual age (PMA). Multivariable regression models were used to estimate the association (OR (95% CI)) between BPD characteristics and NDI defined as cognitive or motor development score <2 SD; severe cerebral palsy; deafness and blindness.

RESULTS

Of 610 (81% of cohort) children assessed at 2 years, 357 (58%) had BPD and 98 (16%) had NDI. Neither FiO₂ >21% for ≥28 days nor mild or moderate BPD at either 36 or 40 weeks' PMA was associated with NDI, but severe BPD was (at 36 weeks' PMA 5.6 (2.0 to 16.0) and at 40 weeks' PMA 16.6 (4.6 to 59.9)). Infants with severe BPD at both 36 and 40 weeks' PMA had lower mental (mean difference -11.4 (-18.5 to -4.3), -25.7(-35.9 to -15.5), respectively) and motor (-7.8 (-14.9 to -0.6), -20.1(-30.7 to -9.5), respectively), developmental scores than infants without BPD.

CONCLUSION

In this cohort, severe BPD was a better independent predictor of NDI at 2 years than mild or moderate BPD. BPD diagnosed at 40 weeks' PMA might allow better identification of infants at highest risk for NDI.

Implementation of the Hammersmith Infant Neurological Examination in a High-Risk Infant Follow-Up Program

BACKGROUND

High-risk infant follow-up programs provide early identification and referral for treatment of neurodevelopmental delays and impairments. In these programs, a standardized neurological examination is a critical component of evaluation for clinical and research purposes.

METHODS

To address primary challenges of provider educational diversity and standardized documentation, we designed an approach to training and implementation of the Hammersmith Infant Neurological Examination with precourse materials, a workshop model, and adaptation of the electronic medical record.

CONCLUSIONS

Provider completion and documentation of a neurological examination were evaluated before and after Hammersmith Infant Neurological Examination training. Standardized training and implementation of the Hammersmith Infant Neurological Examination in a large high-risk infant follow-up is feasible and effective and allows for quantitative evaluation of neurological findings and developmental trajectories.

Use of the Hammersmith Infant Neurological Examination in infants with cerebral palsy: a critical review of the literature

The Hammersmith Infant Neurological Examination (HINE) has been proposed as one of the early neurological examination tools for the diagnosis of cerebral palsy (CP). The aim of the present study was to critically review the existing literature and our experience with the use of the HINE in infants at risk of CP. The published papers confirm that the HINE can play an important role in the diagnosis and prognosis of infants at risk of developing CP, and provide information on aspects of neurological findings impaired in different forms of CP and brain lesions.

Neonatal physiological correlates of near-term brain development on MRI and DTI in very-low-birth-weight preterm infants

Structural brain abnormalities identified at near-term age have been recognized as potential predictors of neurodevelopment in children born preterm. The aim of this study was to examine the relationship between neonatal physiological risk factors and early brain structure in very-low-birth-weight (VLBW) preterm infants using structural MRI and diffusion tensor imaging (DTI) at near-term age.

Structural brain MRI, diffusion-weighted scans, and neonatal physiological risk factors were analyzed in a cross-sectional sample of 102 VLBW preterm infants (BW ≤ 1500 g, gestational age (GA) ≤ 32 weeks), who were admitted to the Lucile Packard Children's Hospital, Stanford NICU and recruited to participate prior to routine near-term brain MRI conducted at 36.6 ± 1.8 weeks postmenstrual age (PMA) from 2010 to 2011; 66/102 also underwent a diffusion-weighted scan. Brain abnormalities were assessed qualitatively on structural MRI, and white matter (WM) microstructure was analyzed quantitatively on DTI in six subcortical regions defined by DiffeoMap neonatal brain atlas. Specific regions of interest included the genu and splenium of the corpus callosum, anterior and posterior limbs of the internal capsule, the thalamus, and the globus pallidus. Regional fractional anisotropy (FA) and mean diffusivity (MD) were calculated using DTI data and examined in relation to neonatal physiological risk factors including gestational age (GA), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), and sepsis, as well as serum levels of C-reactive protein (CRP), glucose, albumin, and total bilirubin.

Brain abnormalities were observed on structural MRI in 38/102 infants including 35% of females and 40% of males. Infants with brain abnormalities observed on MRI had higher incidence of BPD (42% vs. 25%) and sepsis (21% vs. 6%) and higher mean and peak serum CRP levels, respectively, (0.64 vs. 0.34 mg/dL, p = .008; 1.57 vs. 0.67 mg/dL, p= .006) compared to those without. The number of signal abnormalities observed on structural MRI correlated to mean and peak CRP (rho = .316, p = .002; rho = .318, p= .002). The number of signal abnormalities observed on MRI correlated with thalamus MD (left: r= .382, p= .002; right: r= .400, p= .001), controlling for PMA-at-scan. Thalamus WM microstructure demonstrated the strongest associations with neonatal risk factors. Higher thalamus MD on the left and right, respectively, was associated with lower GA (r = −.322, p = .009; r= −.381, p= .002), lower mean albumin (r = −.276, p= .029; r= −.385, p= .002), and lower mean bilirubin (r = −.293, p= .020; r= −.337 p= .007).

Results suggest that at near-term age, thalamus WM microstructure may be particularly vulnerable to certain neonatal risk factors. Interactions between albumin, bilirubin, phototherapy, and brain development warrant further investigation. Identification of physiological risk factors associated with selective vulnerability of certain brain regions at near-term age may clarify the etiology of neurodevelopmental impairment and inform neuroprotective treatment for VLBW preterm infants.

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Biomarkers of inflammation in preterm infants correlated with brain abnormalities detected on near-term structural MRI.

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Biomarkers of inflammation in preterm infants correlated with near-term WM microstructure assessed on DTI.

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Signal abnormalities observed on near-term structural MRI correlated with increased thalamus MD.

Need for supplemental oxygen at discharge in infants with bronchopulmonary dysplasia is not associated with worse neurodevelopmental outcomes at 3 years corrected age

OBJECTIVES

To determine if chronic oxygen dependency (discharge home on supplemental oxygen) in children with bronchopulmonary dysplasia (BPD; defined as requirement for supplemental O2 at 36 weeks postmenstrual age) predicts neurodevelopmental disability rates and growth outcomes at 36 months corrected age (CA).

STUDY DESIGN

Longitudinal cohort study.

SETTING

Southern Alberta regional center located at high altitude.

PARTICIPANTS

Preterm infants weighing ≤1250 grams with no BPD, BPD, and BPD with chronic oxygen dependency.

MAIN OUTCOME MEASURES

Neurodevelopmental and growth outcomes.

RESULTS

Of 1563 preterm infants admitted from 1995-2007, 1212 survived. Complete follow-up data were available for 1030 (85%) children. Children in BPD and BPD with chronic oxygen dependency groups had significantly lower birth weights, gestational ages, prolonged mechanical ventilation and oxygen supplementation and received more postnatal steroids, compared to those without BPD. Children with BPD and BPD with chronic oxygen dependency were more likely to be below the 5th centile in weight and height compared to those without BPD but there was little difference between the BPD and BPD with chronic oxygen dependency groups. After controlling for confounding variables, children who had BPD and BPD with chronic oxygen dependency had higher odds of neurodevelopmental disability compared to those without BPD [OR (odds ratio) 1.9 (95%CI 1.1 to 3.5) and OR 1.8 (1.1 to 2.9), respectively], with no significant difference between BPD and BPD with chronic oxygen dependency [OR 0.9 (95% CI 0.6 to 1.5)].

CONCLUSIONS

BPD and BPD with chronic oxygen dependency in children predicts abnormal neurodevelopmental outcomes at 36 months CA. However, the neurodevelopmental disability rates were not significantly higher in BPD with chronic oxygen dependency children compared to children with BPD only. Compared to those without BPD, growth is impaired in children with BPD and BPD with chronic oxygen dependency, but no difference between the latter two groups.

The quality of general movements after treatment with low-dose dexamethasone in preterm infants at risk of bronchopulmonary dysplasia

BACKGROUND

High-dose dexamethasone (DXM) treatment of preterms at risk of bronchopulmonary dysplasia leads to a deterioration in quality of their general movements (GMs). It is unknown whether low-dose DXM affects GM quality similarly.

OBJECTIVES

To assess the effect of low-dose DXM treatment on the quality of GMs and fidgety GMs (FMs).

METHODS

A prospective study of preterms admitted to our NICU between 2010 and 2012, and treated with DXM (starting dose 0.25 mg/kg/day). We assessed GM/FM quality and calculated their motor optimality score (MOS) before, during, and after treatment up to 3 months postterm. Neurological follow-up was performed between 12 and 36 months. We related risk factors with infants' GM trajectories and MOSs. At 3 months we compared the MOSs of low-dose DXM infants and a historical cohort of infants treated with high-dose DXM or hydrocortisone.

RESULTS

17 infants were included. GM/FM quality improved in 9 out of 13 initially abnormal infants (p = 0.004). Shorter periods of mechanical ventilation and higher birth weights were associated with better GM trajectories (p = 0.032 and p = 0.042, respectively). Infants starting treatment later had higher MOSs on day 7 (p = 0.047). Low-dose DXM infants had higher MOSs than high-dose DXM infants (β = -0.535; 95% CI -0.594 to -0.132; p = 0.003). Out of 17 infants, 2 died, 14 developed normally, and 1 developed with mild neurodevelopmental impairments. Infants whose GMs/FMs remained normal or improved had better outcomes than infants whose GMs/FMs remained abnormal (p = 0.019).

CONCLUSIONS

Out of the 17 infants treated with low-dose DXM, 2 died. Of the surviving infants, neurological functioning improved with the majority having normal neurodevelopment at the age of 12-36 months.