Severity of Bronchopulmonary Dysplasia and Neurodevelopmental Outcome at 2 and 5 Years Corrected Age

Association of a Count of Inpatient Morbidities with 2-Year Outcomes among Infants Born Extremely Preterm

OBJECTIVE

To determine if number of neonatal morbidities is associated with death or severe neurodevelopmental impairment (sNDI) among infants born extremely preterm who survived to 36 weeks' postmenstrual age (PMA).

STUDY DESIGN

This is a retrospective cohort analysis of prospectively collected data from 15 NICHD Neonatal Research Network centers. Neonatal morbidities and 2-year outcomes were examined for 3794 infants born at 22 to 26 weeks' gestation from 2014 through 2019 who survived to 36 weeks' PMA.

RESULTS

Serious brain injury (SBI), bronchopulmonary dysplasia (BPD), and severe retinopathy of prematurity (ROP) had the strongest bivariate associations with death or sNDI (ORs, 95% CI): 3.96 (3.39, 4.64), 3.41 (2.94, 3.95), and 2.66 (2.28, 3.11)], respectively. A morbidity count variable was constructed using these morbidities. The estimated ORs and 95% CI for death or sNDI with any 1, any 2, or all 3 of these morbidities, adjusted for maternal and infant characteristics and hospital of birth, increased from 2.75 (2.25, 3.37) to 6.10 (4.83, 7.70) to 12.90 (9.07, 18.36), respectively. Corresponding rates of late death or sNDI with none, any 1, any 2, and all 3 morbidities were 12.6%, 30.3%, 51.9%, and 69.9%, respectively. The estimated logistic model produced predictions of death or sNDI with moderate discrimination (C-statistic [95% CI]: 0.765 [0.749, 0.782]) and good calibration (Intercept [CITL] = -0.004, slope = 1.026).

CONCLUSIONS

Among infants born extremely preterm who survived to 36 weeks' PMA, a count of SBI, BPD, and severe ROP predicts death or sNDI.

TRIAL REGISTRATION

ClinicalTrials.gov ID Generic Database: NCT00063063.

Most babies born at a French hospital before 26 weeks survived with good outcomes

AIM

The aim of this French study was to determine the neonatal morbidity, mortality and neurodevelopmental outcomes when infants born at the limit of viability reached 2 years of corrected age. We then compared the results with national and international cohorts.

METHODS

This study focused on 294 French infants born from 22 to 25 weeks of gestation in a single tertiary perinatal centre from January 2010 to December 2019. We used data on neonatal mortality and morbidity to calculate the survival rates of infants without moderate to severe neurodevelopmental and sensory deficits at 2 years of corrected age. These outcomes were compared with data from contemporary epidemiological studies of similar populations.

RESULTS

Nearly two-thirds (60.5%) of the infants survived to discharge, with varying rates based on their gestational ages, and 57.3% had no severe neonatal morbidity. The vast majority (90.4%) of the 166 alive and available at 2 years of corrected age were free of moderate to severe neurodevelopmental impairment. Our survival rates exceeded a national French cohort study, but were closely aligned with international cohorts.

CONCLUSION

These findings highlight the importance of incorporating local data into ethical decision-making about life-saving treatment for infants at the limit of viability.

Trajectory of Postnatal Oxygen Requirement in Extremely Preterm Infants

OBJECTIVE

To describe the trends in percentage oxygen requirement and mode of respiratory support delivered to extremely premature infants in the 12 weeks after birth.

STUDY DESIGN

This is a retrospective study of extremely premature infants (≤276/7 weeks) discharged from neonatal intensive care units managed by Pediatrix Medical Group between January 1, 2016, and December 31, 2021. Demographic and daily clinical data (mode of respiratory support and fraction of inspired oxygen [FiO2]) were extracted from the Pediatrix Clinical Data Warehouse.

RESULTS

A total of 16 386 infants with a median gestational age of 25 weeks and birthweight of 765 g were included. There were 3808 (23.2%) infants who died. Of the cohort, 6019 (43.1%) infants who survived to 36 weeks' gestation had bronchopulmonary dysplasia. Median FiO2 at all gestations followed a biphasic pattern with a peak on day of life 1, reduction to a nadir by day 4 to 5, and an increase to a second peak around day 14. Infants born at lower gestational ages had a higher median FiO2 at each time point. At lower gestations, there were higher proportions of infants receiving mechanical ventilation and a later introduction of noninvasive modes.

CONCLUSIONS

Extremely premature infants show a consistent biphasic pattern in percentage of supplemental oxygen required after birth.

[Prognosis of bronchopulmonary dysplasia]

Children with bronchopulmonary dysplasia (BPD) often exhibit severe respiratory problems and significant pulmonary dysfunction during school age and adulthood. Exercise tests show a decline in cardiopulmonary function and physical performance in children with BPD, who also have a higher incidence of pulmonary hypertension. These children generally perform poorly in terms of intelligence, language, and motor development. As they age, the risk of neurodevelopmental disorders increases, and health-related quality of life is also affected. This article reviews the prognosis of the respiratory system, physical capacity, cardiovascular system, nervous system, and health-related quality of life in children with BPD, aiming to improve the management of these patients and enhance their subsequent quality of life.

Identification of serum metabolite biomarkers in premature infants with bronchopulmonary dysplasia: protocol for a multicentre prospective observational cohort study

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is one of the most common and significant complications of preterm birth. It ultimately leads to a decrease in the quality of life for preterm infants and impacts their long-term health. Early prediction and timely intervention are crucial to halting the development of BPD. This study aims to identify the biomarkers that can predict the early occurrence and development of BPD by screening serum metabolites in preterm infants. This will provide strong support for the early prediction of BPD and targeted interventions in future research.

METHODS AND ANALYSIS

This is a prospective, multicentre, open-label, observational cohort study spanning 3 years. It will be conducted in six major neonatal intensive care units in Shenzhen, China, involving preterm infants born at gestational ages <32 weeks. Demographic data and treatment information will be collected prospectively. Serum samples will be collected at five distinct time points: within 24 hours after birth, at 1 week, 2 weeks, 28 days and at 36 weeks postmenstrual age. These samples will undergo analysis using liquid chromatography-tandem mass spectrometry for untargeted metabolomics studies. Participants will be categorised into BPD and non-BPD groups based on their final diagnosis, and metabolite differences between these groups will be analysed. The study aims to enrol 1500 preterm infants with gestational ages <32 weeks over 3 years. A three-step analysis strategy-discovery, validation and clinical testing-will be used to identify and validate the clinical utility of novel biomarkers. Additionally, a nested case-control study will be conducted, matching participants 1:1 with a control group sharing similar BPD risk factors.

ETHICS AND DISSEMINATION

Our protocol has been approved by the Medical Ethics Committees of all participating hospitals, including Peking University Shenzhen Hospital, Shenzhen People's Hospital, Shenzhen Baoan Women's and Children's Hospital, Longgang District Maternity and Child Healthcare Hospital, Nanshan Maternity and Child Healthcare Hospital and Shenzhen Luohu People's Hospital. We will disseminate our study results through academic conferences and peer-reviewed public journals.

TRIAL REGISTRATION NUMBER

ChiCTR2400081615.

Activated DRP1 promotes mitochondrial fission and induces glycolysis in ATII cells under hyperoxia

BACKGROUD

Recent studies have reported mitochondrial damage and metabolic dysregulation in BPD, but the changes in mitochondrial dynamics and glucose metabolic reprogramming in ATII cells and their regulatory relationship have not been reported.

METHODS

Neonatal rats in this study were divided into model (FIO2:85%) and control (FIO2: 21%) groups. Lung tissues were extracted at 3, 7, 10 and 14 postnatal days and then conducted HE staining for histopathological observation. We assessed the expression of mitochondria dynamic associated proteins and glycolysis associated enzymes in lung tissues, primary ATII cells and RLE-6TN cells. Double immunofluorescence staining was used to confirm the co-localization of DRP1 and ATII cells. Real-time analyses of ECAR and OCR were performed with primary ATII cells using Seahorse XF96. ATP concentration was measured using an ATP kit. We treated RLE-6TN cells at 85% hyperoxia for 48 h with mitochondrial fission inhibitor Mdivi-1 to verify the role of DRP1 in regulating glucose metabolic reprogramming.

FINDINGS

We found that hyperoxia causes ATII cells' mitochondrial morphological change. The expression of DRP1 and p-DRP1 increased in lung tissue and primary ATII cells of neonatal rats exposed to hyperoxia. Glycolysis related enzymes including PFKM, HK2, and LDHA were also increased. Hyperoxia inhibited ATP production in ATII cells. In RLE-6TN cells, we verified that the administration of Mdivi-1 could alleviate the enhancement of aerobic glycolysis and fragmentation of mitochondria caused by hyperoxia.

INTERPRETATIONS

Hyperoxia exposure leads to increased mitochondrial fission in ATII cells and mediates the reprogramming of glucose metabolism via the DRP1 signaling pathway. Inhibiting the activation of DRP1 signaling pathway may be a promising therapeutic target for BPD.

Association between bronchopulmonary dysplasia severity and its risk factors and long-term outcomes in three definitions: a historical cohort study

OBJECTIVE

To compare the association of the severity categories of the 2001-National Institutes of Health (NIH), the 2018-NIH and the 2019-Jensen bronchopulmonary dysplasia (BPD) definitions with neurodevelopmental and respiratory outcomes at 2 and 5 years' corrected age (CA), and several BPD risk factors.

DESIGN

Single-centre historical cohort study with retrospective data collection.

SETTING

Infants born between 2009 and 2015 at the Amsterdam University Medical Centers, location Amsterdam Medical Center.

PATIENTS

Preterm infants born at gestational age (GA) <30 weeks and surviving up to 36 weeks' postmenstrual age.

INTERVENTIONS

Perinatal characteristics, (social) demographics and comorbidities were collected from the electronic patient records.

MAIN OUTCOME MEASURES

The primary outcomes were neurodevelopmental impairment (NDI) or late death, and respiratory morbidity at 2 and 5 years' CA. Using logistic regression and Brier scores, we investigated if the ordinal grade severity is associated with incremental increase of adverse long-term outcomes.

RESULTS

584 preterm infants (median GA: 28.1 weeks) were included and classified according to the three BPD definitions. None of the definitions showed a clear ordinal incremental increase of risk for any of the outcomes with increasing severity classification. No significant differences were found between the three BPD definitions (Brier scores 0.169-0.230). Respiratory interventions, but not GA, birth weight or small for GA, showed an ordinal relationship with BPD severity in all three BPD definitions.

CONCLUSION

The severity classification of three BPD definitions showed low accuracy of the probability forecast on NDI or late death and respiratory morbidity at 2 and 5 years' CA, with no differences between the definitions.

Unveiling the Emerging Role of Extracellular Vesicle-Inflammasomes in Hyperoxia-Induced Neonatal Lung and Brain Injury

Extremely premature infants are at significant risk for developing bronchopulmonary dysplasia (BPD) and neurodevelopmental impairment (NDI). Although BPD is a predictor of poor neurodevelopmental outcomes, it is currently unknown how BPD contributes to brain injury and long-term NDI in pre-term infants. Extracellular vesicles (EVs) are small, membrane-bound structures released from cells into the surrounding environment. EVs are involved in inter-organ communication in diverse pathological processes. Inflammasomes are large, multiprotein complexes that are part of the innate immune system and are responsible for triggering inflammatory responses and cell death. Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is pivotal in inflammasome assembly and activating inflammatory caspase-1. Activated caspase-1 cleaves gasdermin D (GSDMD) to release a 30 kD N-terminal domain that can form membrane pores, leading to lytic cell death, also known as pyroptosis. Activated caspase-1 can also cleave pro-IL-1β and pro-IL-18 to their active forms, which can be rapidly released through the GSDMD pores to induce inflammation. Recent evidence has emerged that activation of inflammasomes is associated with neonatal lung and brain injury, and inhibition of inflammasomes reduces hyperoxia-induced neonatal lung and brain injury. Additionally, multiple studies have demonstrated that hyperoxia stimulates the release of lung-derived EVs that contain inflammasome cargos. Adoptive transfer of these EVs into the circulation of normal neonatal mice and rats induces brain inflammatory injury. This review focuses on EV-inflammasomes' roles in mediating lung-to-brain crosstalk via EV-dependent and EV-independent mechanisms critical in BPD, brain injury, and NDI pathogenesis. EV-inflammasomes will be discussed as potential therapeutic targets for neonatal lung and brain injury.

Analysis of variable metabolites in preterm infants with bronchopulmonary dysplasia: a systematic review and meta-analysis

Numerous studies have attempted to identify potential biomarkers for early detection of bronchopulmonary dysplasia (BPD) in preterm infants using metabolomics techniques. However, the presence of consistent evidence remains elusive. Our study aimed to conduct a systematic review and meta-analysis to identify differences in small-molecule metabolites between BPD and non-BPD preterm infants. Through meticulous screening of numerous samples, we identified promising candidates, providing valuable insights for future research. We searched PubMed, the Cochrane Library, Embase, Web of Science, China National Knowledge Internet, Wan-fang database, Chinese Science and Technique Journal Database and Chinese Biomedical Literature Database from inception until January 16, 2024. Studies were comprehensively reviewed against inclusion criteria. We included case-control studies and adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Study quality was assessed with the Newcastle-Ottawa scale. We compared the changes in metabolite levels between the BPD and non-BPD preterm infants. A meta-analysis was conducted on targeted metabolomics research data based on the strategy of standardized mean differences (MD) and 95% confidence intervals (CI).Fifteen studies (1357 participants) were included. These clinical-based metabolomics studies clarified 110 differential metabolites between BPD and non-BPD preterm infants. The meta-analysis revealed higher glutamate concentration in the BPD group compared to the non-BPD group (MD = 1, 95% CI 0.59 to 1.41, p < 0.00001). Amino acids were identified as the key metabolites distinguishing preterm infants with and without BPD, with glutamate potentially serving as a BPD predictor in this population.

Analysis of blood metabolite characteristics at birth in preterm infants with bronchopulmonary dysplasia: an observational cohort study

Background

To analyze the characteristics of blood metabolites within 24 h after birth in preterm infants with bronchopulmonary dysplasia (BPD) and to identify biomarkers for predicting the occurrence of BPD.

Methods

Dried blood spots (DBS) were collected at birth from preterm infants with gestational age (GA) of less than 32 weeks in the cohort. The infants were divided into the BPD group and non-BPD group based on whether they eventually developed BPD. Dried blood spot filter papers were prepared from venous blood collected within the first 24 h of life. Metabolites were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and analyzed using the R software package.

Results

DBS samples from 140 infants with the GA < 32 weeks were used in the study, with 4 infants who died being excluded. Among the remaining 136 preterm infants, 38 developed BPD and 98 did not. To control for GA differences, we conducted a subgroup analysis. In the GA 24+4-27+6 weeks subgroup, we observed a significant decrease in histidine levels and the ornithine/citrulline ratio in the BPD group. Additionally, the ratios of acylcarnitines C3/C0 and C5/C0 were also significantly reduced.

Conclusions

Metabolic markers in DBS within 24 h after birth are promising for predicting the occurrence of BPD in preterm infants with GA < 28 weeks.

Clinical Trial Registration

[https://www.chictr.org.cn/], identifier [ChiCTR2100048293, ChiCTR2400081615].

Neonatal multimorbidity and the phenotype of premature aging in preterm infants

Multimorbidity is the co-occurrence of multiple chronic health problems, associated with aging, frailty, and poor functioning. Children born preterm experience more multimorbid conditions in early life compared to term-born peers. Though neonatal multimorbidity is linked to poor health-related quality of life, functional outcomes, and peer group participation, gaps in our theoretical understanding and conceptualization remain. Drawing from life course epidemiology and the Developmental Origins of Heath and Disease models, we offer a framework that neonatal multimorbidity reflects maturational vulnerability posed by preterm birth. The impact of such vulnerability on health and development may be further amplified by adverse exposures and interventions within the environment of the neonatal intensive care unit. This can be exacerbated by disadvantaged home or community contexts after discharge. Uncovering the physiologic and social antecedents of multiple morbid conditions in the neonatal period and their biological underpinnings will allow for more accurate risk-prediction, counseling, and care planning for preterm infants and their families. According to this framework, the maturational vulnerability to multimorbidity imparted by preterm birth and its negative effects on health and development are not predetermined or static. Elucidating pathways of early biologic and physical aging will lead to improvements in care and outcomes. IMPACT: Multimorbidity is associated with significant frailty and dysfunction among older adults and is indicative of early physiologic aging. Preterm infants commonly experience multimorbidities in the newborn period, an underrecognized threat to long-term health and development. We offer a novel framework incorporating multimorbidity, early cellular aging, and life course health development to innovate risk-prediction, care-planning, and therapeutics.

Bronchopulmonary dysplasia to predict neurodevelopmental impairment in infants born extremely preterm

BACKGROUND

Bronchopulmonary dysplasia (BPD) in extremely low gestational age neonates (ELGANs) was associated with neurodevelopmental impairment (NDI). However, the best endpoint of BPD assessment to predict subsequent NDI remains unclear.

METHODS

We re-analyzed the PREMILOC trial, previously designed to test the effect of prophylactic hydrocortisone on survival without BPD at 36 weeks of postmenstrual age (BPDW36) in ELGANs, to compare predictive models of NDI considering baseline characteristics, respiratory course up to and BPD status at 36 or 40 weeks of postmenstrual age (BPDW36/BPDW40).

RESULTS

Among 404/519 (77.8%) infants enrolled in the trial alive at 2 years of age, all neurocognitive scores were available for 302 (74.8%) patients. Gestational diabetes and sex were identified as the only statistically significant baseline predictors of NDI. Adding BPDW40 to this baseline model was found to be superior to predict NDI compared to BPDW36, leading to a mean difference of the developmental quotient of -6.7 points (95% confidence interval: -10.0 to -3.50, P < 0.001). The prophylactic hydrocortisone treatment effect on survival without BPDW40 was found to be highly significant (OR = 2.08 [95% confidence interval: 1.36 to 3.17], P < 0.001).

CONCLUSIONS

These data suggest a better accuracy of BPDW40 to predict NDI in ELGANs, an important finding for future clinical trials and research in drug development.

REGISTRATION NUMBERS

EudraCT number 2007-002041-20, ClinicalTrial.gov number, NCT00623740.

IMPACT

The best endpoint to assess BPD as a surrogate to predict neurocognitive impairment in infants born extremely preterm remains unclear. This study strongly suggests a better discriminative value of BPD as assessed at 40 weeks of postmenstrual age (instead of 36 weeks) to predict neurocognitive impairments at 2 years of age in children born extremely preterm. This study supports the switch up to 40 weeks of the primary outcome chosen in future clinical trials designed to prevent BPD. Our data also provide evidence of the beneficial effect of HC on preventing BPD at full-term equivalent age.

Delivery room resuscitation and short-term outcomes in very preterm infants: a multicenter cross-sectional study in China

Objective

To explore the risk factors of delivery room (DR) resuscitation and assess the association of DR resuscitation with neonatal outcomes in very preterm infants (VPIs).

Methods

A multicenter retrospective cross-sectional study included VPIs with gestational age (GA) <32 weeks born between January, 2022 and June, 2023 and admitted to neonatal intensive care units of six tertiary hospitals in Shenzhen within 24 h after birth. They were divided into routine care group, positive-pressure ventilation (PPV) group, and endotracheal intubation (ETT) group based on the highest intensity of resuscitation received at birth. The association of antepartum and intrapartum risk factors and short-term outcomes with the intensity of DR resuscitation was evaluated.

Results

Of 683 infants included in this study, 170 (24.9%) received routine care, 260 (38.1%) received bag and mask ventilation or T-piece ventilation and 253 (37%) received ETT. Among the antepartum and intrapartum factors, exposure to antenatal steroids (ANS) decreased the likelihood of ETT. Increasing GA decreased the likelihood of receiving a higher level of DR resuscitation. Among the neonatal outcomes, increasing intensity of DR resuscitation was associated with a raise in the risk of Bronchopulmonary dysplasia. Higher levels of DR resuscitation were associated with the risk of early-onset sepsis. ETT was significantly associated with an increased risk of death.

Conclusion

Among VPIs, low GA and no ANS use increased the risk of high-intensity DR resuscitation interventions; and those who receiving ETT were associated with an increased risk of adverse clinical outcomes.

Effects of postnatal corticosteroids on lung development in newborn animals. A systematic review

BACKGROUND

Postnatal systemic corticosteroids reduce the risk of bronchopulmonary dysplasia but the effect depends on timing, dosing, and type of corticosteroids. Animal studies may provide valuable information on these variable effects. This systematic review summarizes the effects of postnatal systemic corticosteroids on lung development in newborn animals.

METHODS

A systematic search was performed in PubMed and Embase in December 2022. The protocol was published on PROSPERO (CRD42021177701).

RESULTS

Of the 202 eligible studies, 51 were included. Only newborn rodent studies met the inclusion criteria. Most studies used dexamethasone (98%). There was huge heterogeneity in study outcome measures and corticosteroid treatment regimens. Reporting of study quality indicators was mediocre and risk of bias was unclear due to poor reporting of study methodology. Meta-analysis showed that postnatal corticosteroids caused a decrease in body weight as well as persistent alveolar simplification. Subgroup analyses revealed that healthy animals were most affected.

CONCLUSION

In newborn rodents, postnatal systemic corticosteroids have a persistent negative effect on body weight and lung development. There was huge heterogeneity in experimental models, mediocre study quality, unclear risk of bias, and very small subgroups for meta-analysis which limited firm conclusions.

IMPACT

Postnatal corticosteroids reduce the risk of bronchopulmonary dysplasia but the effect depends on timing, dosing, and type of corticosteroids while the underlying mechanism of this variable effect is unknown. This is the first systematic review and meta-analysis of preclinical newborn animal studies reviewing the effect of postnatal systemic corticosteroids on lung development. In newborn rodent models, postnatal corticosteroids have a persistent negative effect on body weight and lung alveolarization, especially in healthy animals.

Survival of Infants Born at 22 to 25 Weeks' Gestation Receiving Care in the NICU: 2020-2022

OBJECTIVE

To provide contemporary data on infants inborn at 22 to 25 weeks' gestation and receiving care at level 3 and 4 neonatal intensive care units in the United States.

METHODS

Vermont Oxford Network members submitted data on infants born at 22 to 25 weeks' gestation at a hospital with a level 3 or 4 NICU from 2020 to 2022. The primary outcome was survival to hospital discharge. Secondary outcomes included survival without severe complications, length of stay, and technology dependence.

RESULTS

Overall, 22 953 infants at 636 US hospitals were included. Postnatal life support increased from 68.0% at 22 weeks to 99.8% at 25 weeks. The proportion of infants born at 22 weeks receiving postnatal life support increased from 61.6% in 2020 to 73.7% in 2022. For all infants, survival ranged from 24.9% at 22 weeks to 82.0% at 25 weeks. Among infants receiving postnatal life support, survival ranged from 35.4% at 22 weeks to 82.0% at 25 weeks. Survival without severe complications ranged from 6.3% at 22 weeks to 43.2% at 25 weeks. Median length of stay ranged from 160 days at 22 weeks to 110 days at 25 weeks. Among survivors, infants born at 22 weeks had higher rates of technology dependence at discharge home than infants born at later gestational ages.

CONCLUSIONS

Survival ranged from 24.9% at 22 weeks to 82.1% at 25 weeks, with low proportions of infants surviving without complications, prolonged lengths of hospital stay, and frequent technology dependence at all gestational ages.

Association between early metabolic acidosis and bronchopulmonary dysplasia/death in preterm infants born at less than 28 weeks' gestation: an observational cohort study

BACKGROUND

Metabolic acidosis occurs frequently during the first postnatal days in extremely preterm infants and is mainly attributed to renal immaturity. Recent studies suggested a link between metabolic acidosis and the development of BPD. The aim of this study was to systematically investigate the association between severe metabolic acidosis during the first two weeks of life and bronchopulmonary dysplasia (BPD) / mortality among preterm infants born before 28 weeks' gestation.

METHODS

Monocentric observational cohort study including 1748 blood gas samples of 138 extremely preterm infants born 2020-2022. Metabolic acidosis was defined as pH < 7.2 with base excess (BE) < -10 mmol/L or standard bicarbonate (SBC) < 12 mmol/L. Primary outcome was BPD and/or death at 36 weeks postmenstrual age.

RESULTS

Fifty-six (40.6%) infants had BPD/death. Metabolic acidosis occurred in 50.0% of infants with BPD/death, compared to 22.0% of BPD-free survivors (p = 0.001) during the first 14 postnatal days. Minimum pH (median 7.12 vs. 7.19, p < 0.001), BE (median -10.9 vs. -9.5 mmol/L, p = 0.005), SBC (median 14.7 vs. 16.1 mmol/L, p < 0.001) were different between the two groups. After adjusting for confounders, pH (postnatal days 2-6), BE (postnatal day 3) and SBC (postnatal days 2-4) were significantly lower in infants with BPD/death. Metabolic acidosis on postnatal days 1-7 was associated with higher odds of BPD (adjusted Odds Ratio (aOR) 3.461, 95% CI 1.325-9.042) and BPD/death (aOR 3.087, 95% CI 1.225-7.778).

CONCLUSIONS

Metabolic acidosis during the first week of life was associated with higher odds of BPD/death in extremely preterm infants.

miRNA Signatures in Bronchopulmonary Dysplasia: Implications for Biomarkers, Pathogenesis, and Therapeutic Options

Bronchopulmonary dysplasia (BPD) is a chronic lung disease in premature infants characterized by alveolar dysplasia, vascular simplification and dysmorphic vascular development. Supplemental oxygen and mechanical ventilation commonly used as life-saving measures in premature infants may cause BPD. microRNAs (miRNAs), a class of small, non-coding RNAs, regulate target gene expression mainly through post-transcriptional repression. miRNAs play important roles in modulating oxidative stress, proliferation, apoptosis, senescence, inflammatory responses, and angiogenesis. These cellular processes play pivotal roles in the pathogenesis of BPD. Accumulating evidence demonstrates that miRNAs are dysregulated in the lung of premature infants with BPD, and in animal models of this disease, suggesting contributing roles of dysregulated miRNAs in the development of BPD. Therefore, miRNAs are considered promising biomarker candidates and therapeutic agents for this disease. In this review, we discuss how dysregulated miRNAs and their modulation alter cellular processes involved in BPD. We then focus on therapeutic approaches targeting miRNAs for BPD. This review provides an overview of miRNAs as biomarkers, and highlights potential pathogenic roles, and therapeutic strategies for BPD using miRNAs.

The developmental phenotype of motor delay in extremely preterm infants following early-life respiratory adversity is influenced by brain dysmaturation in the parietal lobe

BACKGROUND

Research indicates that preterm infants requiring prolonged mechanical ventilation often exhibit suboptimal neurodevelopment at follow-up, coupled with altered brain development as detected by magnetic resonance imaging (MRI) at term-equivalent age (TEA). However, specific regions of brain dysmaturation and the subsequent neurodevelopmental phenotype following early-life adverse respiratory exposures remain unclear. Additionally, it is uncertain whether brain dysmaturation mediates neurodevelopmental outcomes after respiratory adversity. This study aims to investigate the relationship between early-life adverse respiratory exposures, brain dysmaturation at TEA, and the developmental phenotype observed during follow-up in extremely preterm infants.

METHODS

89 infants born < 29 weeks' gestation from 2019 to 2021 received MRI examinations at TEA for structural and lobe brain volumes, which were adjusted with sex-and-postmenstrual-age expected volumes for volume residuals. Assisted ventilation patterns in the first 8 postnatal weeks were analyzed using kmlShape analyses. Patterns for motor, cognition, and language development were evaluated from corrected age 6 to 12 months using Bayley Scales of Infant Development, third edition. Mediation effects of brain volumes between early-life respiratory exposures and neurodevelopmental phenotypes were adjusted for sex, gestational age, maternal education, and severe brain injury.

RESULTS

Two distinct respiratory trajectories with varying severity were identified: improving (n = 35, 39%) and delayed improvement (n = 54, 61%). Compared with the improving group, the delayed improvement group exhibited selectively reduced brain volume residuals in the parietal lobe (mean - 4.9 cm3, 95% confidence interval - 9.4 to - 0.3) at TEA and lower motor composite scores (- 8.7, - 14.2 to - 3.1) at corrected age 12 months. The association between delayed respiratory improvement and inferior motor performance (total effect - 8.7, - 14.8 to - 3.3) was partially mediated through reduced parietal lobe volume (natural indirect effect - 1.8, - 4.9 to - 0.01), suggesting a mediating effect of 20%.

CONCLUSIONS

Early-life adverse respiratory exposure is specifically linked to the parietal lobe dysmaturation and neurodevelopmental phenotype of motor delay at follow-up. Dysmaturation of the parietal lobe serves as a mediator in the connection between respiratory adversity and compromised motor development. Optimizing respiratory critical care may emerge as a potential avenue to mitigate the consequences of altered brain growth and motor developmental delay in this extremely preterm population.

Randomized controlled trial of enteral vitamin D supplementation (ViDES) in infants <28 weeks gestational age or <1000 g birth weight: study protocol

BACKGROUND

Vitamin D is necessary to develop healthy lungs and other organs early in life. Most infants born before 28 weeks' gestation have low vitamin D levels at birth and a limited intake during the first month. Enteral vitamin D supplementation is inexpensive and widely used. The appropriate supplementation regimen for extremely preterm infants is controversial, and the effect of different regimens on their blood levels and outcomes is unclear.

METHODS

Randomized, blinded comparative effectiveness trial to compare two vitamin D supplementation regimens for inborn infants <28 weeks gestation or <1000 g birth weight at a large academic center in the United States. Infants are stratified by birth weight and randomized within 96 h after birth to either routine supplementation (400 IU/day with established feedings) or increased supplementation (800 IU/day with any feedings) during the first 28 days after birth. We hypothesize that the higher and early vitamin D dose (800 IU/day with early feeding) compared to placebo plus routine dose (400 IU/day with established feeding) will substantially increase total 25-hydroxyvitamin D3 levels measured as state-of-art at 1 month, reduce respiratory support at 36 weeks' postmenstrual age (on an ordinal scale predictive of later adverse outcomes), and improve or at least not worsen other important secondary outcomes. The infants in the study will follow up at 22-26 months' corrected age (~2 years) with blinded certified examiners to evaluate neurodevelopmental outcomes. The sample size of a minimum of 180 infants provides >90% power to detect a >95% posterior probability of a 33% increase in serum 25-hydroxy vitamin D3 and >80% power to detect a >80% posterior probability of a relative risk decrease of 20% of reducing respiratory support by intention-to-treat Bayesian analyses using a neutral prior probability.

DISCUSSION

Our study will help clarify the uncertain relationship of vitamin D supplementation and its associated serum metabolites to clinical outcomes of extremely preterm infants. Confirmation of our hypotheses would prompt reconsideration of the supplementation regimens used in extremely preterm infants and justify a large multicenter study to verify the generalizability of the results.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05459298. Registered on July 14, 2022.

Randomized Controlled Trial of Enteral Vitamin D Supplementation (ViDES) in Infants <28 Weeks Gestational Age or <1000 Grams Birth Weight: Study Protocol

Background

Vitamin D is necessary to develop healthy lungs and other organs early in life. Most infants born before 28 weeks' gestation have low vitamin D levels at birth and a limited intake during the first month. Enteral vitamin D supplementation is inexpensive and widely used. The appropriate supplementation regimen for extremely preterm infants is controversial, and the effect of different regimens on their blood levels and outcomes is unclear.

Methods

Randomized, blinded comparative effectiveness trial to compare two vitamin D supplementation regimens for inborn infants <28 weeks gestation or <1000 grams birth weight at a large academic center in the United States.Infants are stratified by birth weight and randomized within 96 hours after birth to either routine supplementation (400 IU/day with established feedings) or increased supplementation (800 IU/day with any feedings) during the first 28 days after birth.We hypothesize that the higher and early vitamin D dose (800 IU/d with early feeding) compared to placebo plus routine dose (400 IU/d with established feeding) will substantially increase total 25-hydroxyvitamin D3 levels measured as state-of-art at one month, reduce respiratory support at 36 weeks' postmenstrual age (on an ordinal scale predictive of later adverse outcomes) and improve or at least not worsen other important secondary outcomes. The infants in the study will follow up at 22-26 months' corrected age (~2 years) with blinded certified examiners to evaluate neurodevelopmental outcomes.The sample size of a minimum of 180 infants provides >90% power to detect a >95% posterior probability of a 33% increase in serum 25-hydroxy vitamin D3 and >80% power to detect a >80% posterior probability of a relative risk decrease of 20% of reducing respiratory support by intention-to-treat Bayesian analyses using a neutral prior probability.

Discussion

Our study will help clarify the uncertain relationship of vitamin D supplementation and its associated serum metabolites to clinical outcomes of extremely preterminfants. Confirmation of our hypotheses would prompt reconsideration of the supplementation regimens used in extremely preterm infants and justify a large multicenter study to verify the generalizability of the results.

Trial registration

ClinicalTrials.gov registered on July 14, 2022 (NCT05459298).

Optimal Strategies of Mechanical Ventilation: Can We Avoid or Reduce Lung Injury?

BACKGROUND

Despite the increasing use of non-invasive support modalities, many preterm infants still need invasive mechanical ventilation. Mechanical ventilation can lead to so-called ventilator-induced lung injury, which is considered an important risk factor in the development of bronchopulmonary dysplasia. Understanding the concepts of lung protective ventilation strategies is imperative to reduce the risk of BPD.

SUMMARY

Overdistension, atelectasis, and oxygen toxicity are the most important risk factors for VILI. A lung protective ventilation strategy should therefore optimize lung volume (resolve atelectasis), limit tidal volumes, and reduce oxygen exposure. Executing such a lung protective ventilation strategy requires basic knowledge on neonatal lung physiology. Studies have shown that volume-targeted ventilation (VTV) stabilizes tidal volume delivery, reduces VILI, and reduces BPD in preterm infants with respiratory distress syndrome. High-frequency ventilation (HFV) also reduces BPD although the effect is modest and inconsistent. It is unclear if these benefits also apply to infants with more heterogeneous lung disease.

KEY MESSAGES

Understanding basic physiology and the concept of ventilator-induced lung injury is essential in neonatal mechanical ventilation. Current evidence suggests that the principles of lung protective ventilation are best captured by VTV and HFV.

Neurodevelopmental outcomes of extremely preterm infants with bronchopulmonary dysplasia (BPD) - A retrospective cohort study

OBJECTIVE

To investigate the neurodevelopmental outcomes for preterm infants born < 29 weeks gestation with/without bronchopulmonary dysplasia (BPD).

STUDY DESIGN

Preterm infants < 29 weeks' gestation born 2007-2018 in New South Wales and the Australian Capital Territory, Australia, were included. Infants who died < 36 weeks' postmenstrual age and those with major congenital anomalies were excluded. Subjects were assessed at 18-42 months corrected age using the Bayley Scales of Infant Development, 3rd edition.

RESULTS

1436 infants without BPD (non-BPD) and 1189 infants with BPD were followed. The BPD group, 69 % infants were discharged without respiratory support (BPD1), 29 % on oxygen (BPD2) and 2 % on pressure support/tracheostomy (BPD3). Moderate neurodevelopmental impairment (NDI) was evident in 5.7 % of non-BPD infants, 11 % BPD1, 15 % BPD2, 15 % BPD3 infants. Severe NDI was seen in 1.7 % non-BPD infants, 3.4 % BPD1, 7.3 % BPD2, 35 % BPD3 infants. After adjusting for confounders, infants with BPD2 (OR 2.24, 99.9 % CI 1.25 to 5.77) or BPD3 (OR 5.99, 99.9 % CI 1.27 to 46.77) were more likely to have moderate-severe NDI compared to non-BPD infants.

CONCLUSION

The majority of infants with BPD were discharged home without respiratory support and had better neurocognitive outcomes in early childhood compared to those that required home-based oxygen or respiratory support.

Use and Impact of Pessary, Cerclage, and Progesterone for the Secondary Prevention of Preterm Birth: Data from the German Neonatal Network

BACKGROUND

To evaluate the use and effect of cervical stitch cerclage, pessary, and progesterone on pregnancy outcome in mothers of very low birth weight infants (VLBWI) born<32 weeks of gestation in the German Neonatal Network (GNN).

METHODS

The GNN is a population-based cohort study enrolling VLBWI since 2009. We included 575 neonates from 424 mothers into our analysis, who were born between 2015 and 2019, after prenatal intervention with cerclage, pessary, progesterone or a combination between 20/0 to 25/0 weeks of gestation to prevent preterm birth. Median intervention-to-birth interval was the primary endpoint.

RESULTS

231 of 424 pregnant women had a cerclage only (54.5%), 76 women a pessary only (17.9%), and 27 were prescribed progesterone only (15.3%). The most common combination treatment (>1 intervention group) was cerclage plus progesterone (n=27), followed by cerclage plus pessary (n=13). The median intervention-to-birth interval for the whole cohort was 24 days (IQR 19.0 days). The earlier the intervention was started, the longer the intervention-to-birth interval lasted: When started at 20 weeks, the interval was 34 days in contrast to 11.5 days, when started at 25 weeks. The >1 group was born at a significantly higher median GA with 27.0 weeks (IQR 2.9 weeks) and a higher median birth weight of 980 g (IQR 394 g) accordingly.

CONCLUSION

We propose that the earliest possible start of intervention leads to the most efficient pregnancy prolongation.

Long-term Effects of Intratracheal Budesonide and Surfactant for the Prevention of Bronchopulmonary Dysplasia: A Narrative Review

OBJECTIVE

This study aimed to compare the safety and efficacy of intratracheal administration of budesonide and surfactant with surfactant alone for bronchopulmonary dysplasia (BPD) prevention in premature infants with respiratory distress syndrome.

STUDY DESIGN

A literature search was performed in MEDLINE, Embase, Cochrane, ClinicalTrials.gov, and gray literature. Assessment of quality was conducted using CASP tool, ROBIS tool, and GRADE framework.

RESULTS

A systematic review and meta-analysis and three observational studies were identified. Budesonide was associated with reduced incidence and severity of BPD, reduced mortality, patent ductus arteriosus, need for additional surfactant doses, hypotension, duration of invasive ventilation, hospital stays, salbutamol prescriptions, and hospitalizations in the first 2 years of life. The safety of budesonide on neurodevelopmental outcomes at 2 to 3 years of corrected age was reported.

CONCLUSION

Budesonide might be associated with a reduction in BPD incidence and severity, without evidence of impaired neurodevelopment at 2 to 3 years of age. According to the GRADE framework, the level of evidence is low due to significant heterogeneity of studies and other bias.

KEY POINTS

· BPD prevention is urgently needed.. · Intratracheal budesonide and surfactant for neonatal RDS could reduce BPD.. · The grade of evidence for this intervention is low due to study heterogeneity and other bias..

Corticosteroids for the prevention and treatment of bronchopulmonary dysplasia: an overview of systematic reviews

BACKGROUND

Bronchopulmonary dysplasia (BPD) remains an important complication of prematurity. Pulmonary inflammation plays a central role in the pathogenesis of BPD, explaining the rationale for investigating postnatal corticosteroids. Multiple systematic reviews (SRs) have summarised the evidence from numerous randomised controlled trials (RCTs) investigating different aspects of administrating postnatal corticosteroids. Besides beneficial effects on the outcome of death or BPD, potential short- and long-term harms have been reported.

OBJECTIVES

The primary objective of this overview was to summarise and appraise the evidence from SRs regarding the efficacy and safety of postnatal corticosteroids in preterm infants at risk of developing BPD.

METHODS

We searched the Cochrane Database of Systematic Reviews, MEDLINE, Embase, CINAHL, and Epistemonikos for SRs in April 2023. We included all SRs assessing any form of postnatal corticosteroid administration in preterm populations with the objective of ameliorating pulmonary disease. All regimens and comparisons were included. Two review authors independently checked the eligibility of the SRs comparing corticosteroids with placebo, and corticosteroids with different routes of administration and regimens. The included outcomes, considered key drivers in the decision to administer postnatal corticosteroids, were the composite outcome of death or BPD at 36 weeks' postmenstrual age (PMA), its individual components, long-term neurodevelopmental sequelae, sepsis, and gastrointestinal tract perforation. We independently assessed the methodological quality of the included SRs by using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) and ROBIS (Risk Of Bias In Systematic reviews) tools. We assessed the certainty of the evidence using GRADE. We provided a narrative description of the characteristics, methodological quality, and results of the included SRs.

MAIN RESULTS

We included nine SRs (seven Cochrane, two non-Cochrane) containing 87 RCTs, 1 follow-up study, and 9419 preterm infants, investigating the effects of postnatal corticosteroids to prevent or treat BPD. The quality of the included SRs according to AMSTAR 2 varied from high to critically low. Risk of bias according to ROBIS was low. The certainty of the evidence according to GRADE ranged from very low to moderate. Early initiated systemic dexamethasone (< seven days after birth) likely has a beneficial effect on death or BPD at 36 weeks' PMA (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.81 to 0.95; number needed to treat for an additional beneficial outcome (NNTB) 16, 95% CI 10 to 41; I2 = 39%; 17 studies; 2791 infants; moderate-certainty evidence) and on BPD at 36 weeks' PMA (RR 0.72, 95% CI 0.63 to 0.82; NNTB 13, 95% CI 9 to 21; I2 = 39%; 17 studies; 2791 infants; moderate-certainty evidence). Early initiated systemic hydrocortisone may also have a beneficial effect on death or BPD at 36 weeks' PMA (RR 0.90, 95% CI 0.82 to 0.99; NNTB 18, 95% CI 9 to 594; I2 = 43%; 9 studies; 1376 infants; low-certainty evidence). However, these benefits are likely accompanied by harmful effects like cerebral palsy or neurosensory disability (dexamethasone) or gastrointestinal perforation (both dexamethasone and hydrocortisone). Late initiated systemic dexamethasone (≥ seven days after birth) may have a beneficial effect on death or BPD at 36 weeks' PMA (RR 0.75, 95% CI 0.67 to 0.84; NNTB 5, 95% CI 4 to 9; I2 = 61%; 12 studies; 553 infants; low-certainty evidence), mostly contributed to by a beneficial effect on BPD at 36 weeks' PMA (RR 0.76, 95% CI 0.66 to 0.87; NNTB 6, 95% CI 4 to 13; I2 = 14%; 12 studies; 553 infants; low-certainty evidence). No harmful side effects were shown in the outcomes chosen as key drivers to the decision to start or withhold late systemic dexamethasone. No effects, either beneficial or harmful, were found in the subgroup meta-analyses of late hydrocortisone studies. Early initiated inhaled corticosteroids probably have a beneficial effect on death and BPD at 36 weeks' PMA (RR 0.86, 95% CI 0.75 to 0.99; NNTB 19, 95% CI not applicable; I2 = 0%; 6 studies; 1285 infants; moderate-certainty evidence), with no apparent adverse effects shown in the SRs. In contrast, late initiated inhaled corticosteroids do not appear to have any benefits or harms. Endotracheal instillation of corticosteroids (budesonide) with surfactant as a carrier likely has a beneficial effect on death or BPD at 36 weeks' PMA (RR 0.60, 95% CI 0.49 to 0.74; NNTB 4, 95% CI 3 to 6; I2 = 0%; 2 studies; 381 infants; moderate-certainty evidence) and on BPD at 36 weeks' PMA. No evidence of harmful effects was found. There was little evidence for effects of different starting doses or timing of systemic corticosteroids on death or BPD at 36 weeks' PMA, but potential adverse effects were observed for some comparisons. Lowering the dose might result in a more unfavourable balance of benefits and harms. Moderately early initiated systemic corticosteroids, compared with early systemic corticosteroids, may result in a higher incidence of BPD at 36 weeks' PMA. Pulse dosing instead of continuous dosing may have a negative effect on death and BPD at 36 weeks' PMA. We found no differences for the comparisons of inhaled versus systemic corticosteroids.

AUTHORS' CONCLUSIONS

This overview summarises the evidence of nine SRs investigating the effect of postnatal corticosteroids in preterm infants at risk for BPD. Late initiated (≥ seven days after birth) systemic administration of dexamethasone is considered an effective intervention to reduce the risk of BPD in infants with a high risk profile for BPD, based on a favourable balance between benefits and harms. Endotracheal instillation of corticosteroids (budesonide) with surfactant as a carrier is a promising intervention, based on the beneficial effect on desirable outcomes without (so far) negative side effects. Pending results of ongoing large, multicentre RCTs investigating both short- and long-term effects, endotracheal instillation of corticosteroids (budesonide) with surfactant as a carrier is not appropriate for clinical practice at present. Early initiated (< seven days after birth) systemic dexamethasone and hydrocortisone and late initiated (≥ seven days after birth) hydrocortisone are considered ineffective interventions, because of an unfavourable balance between benefits and harms. No conclusions are possible regarding early and late inhaled corticosteroids, as more research is needed.

Relationships of Severity of Bronchopulmonary Dysplasia with Adverse Neurodevelopmental Outcomes and Poor respiratory Function at 7-8 Years of Age

OBJECTIVE

To clarify the relationships of three definitions of severity of bronchopulmonary dysplasia (BPD) with adverse neurodevelopmental and respiratory outcomes at early school-age.

STUDY DESIGN

Participants comprised 218 consecutive survivors to 7-8 years of age born either <28 weeks' gestation or weighing <1000 g in Victoria, Australia, in 2005. BPD was classified as none, Grade 1 (mild), Grade 2 (moderate), or Grade 3 (severe), using two commonly accepted definitions: 1) Jobe2001, and 2) Higgins2018, and our own 3) VICS2005, adapted from Jensen2019. Outcomes included major neurodevelopmental disability, low intelligence quotient and academic achievement, poor motor function, and poor respiratory function as assessed by spirometry. Outcomes for children with each grade of BPD were compared with children with no BPD.

RESULTS

Of the 218 survivors, 132 (61%) had BPD on Jobe2001 criteria, and 113 (52%) had BPD on both Higgins2018 and VICS2005 criteria. Grade 1 on any criteria was not associated with any adverse neurodevelopmental outcomes. Grade 1 on both Higgins2018 and VICS2005 was associated with reduced spirometry. Grade 2 on both Higgins2018 and VICS2005, and Grade 3 on all criteria were associated with increased risk for both adverse neurodevelopmental and respiratory outcomes.

CONCLUSIONS

Compared with no BPD, receiving additional oxygen up to 29% but no positive pressure support at 36 weeks' postmenstrual age increased the risk of abnormal respiratory function but not adverse neurodevelopment. Receiving ≥30% oxygen or any positive pressure support at 36 weeks increased the risk of both adverse outcomes.

Identifying effect modifiers of systemic hydrocortisone treatment initiated 7-14 days after birth in ventilated very preterm infants on long-term outcome: secondary analysis of a randomised controlled trial

OBJECTIVE

To explore clinical effect modifiers of systemic hydrocortisone in ventilated very preterm infants for survival and neurodevelopmental outcome at 2 years' corrected age (CA).

DESIGN

Secondary analysis of a randomised placebo-controlled trial.

SETTING

Dutch and Belgian neonatal intensive care units.

PATIENTS

Infants born <30 weeks' gestational age (GA), ventilator-dependent in the second week of postnatal life.

INTERVENTION

Infants were randomly assigned to systemic hydrocortisone (cumulative dose 72.5 mg/kg; n=182) or placebo (n=190).

MAIN OUTCOME MEASURES

The composite of death or neurodevelopmental impairment (NDI) at 2 years' CA and its components. Candidate effect modifiers (GA, small for GA, respiratory index, sex, multiple births, risk of moderate/severe bronchopulmonary dysplasia or death) were analysed using regression models with interaction terms and subpopulation treatment effect pattern plots.

RESULTS

The composite outcome was available in 356 (96.0%) of 371 patients (one consent withdrawn). For this outcome, treatment effect heterogeneity was seen across GA subgroups (<27 weeks: hydrocortisone (n=141) vs placebo (n=156), 54.6% vs 66.2%; OR 0.61 (95% CI 0.38 to 0.98); ≥27 weeks: hydrocortisone (n=30) vs placebo (n=31), 66.7% vs 45.2%; OR 2.43 (95% CI 0.86 to 6.85); p=0.02 for interaction). This effect was also found for the component death (<27 weeks: 20.1% vs 32.1%; OR 0.53 (95% CI 0.32 to 0.90); ≥27 weeks: 28.1% vs 16.1%; OR 2.04 (95% CI 0.60 to 6.95); p=0.049 for interaction) but not for the component NDI. No differential treatment effects were observed across other subgroups.

CONCLUSION

This secondary analysis suggests that in infants <27 weeks' GA, systemic hydrocortisone may improve the outcome death or NDI, mainly driven by its component death. There was insufficient evidence for other selected candidate effect modifiers.

Effect of Systemic Hydrocortisone on Brain Abnormalities and Regional Brain Volumes in Ventilator-dependent Infants Born Preterm: Substudy of the SToP-BPD Study

OBJECTIVE

To evaluate whether a high cumulative dose of systemic hydrocortisone affects brain development compared with placebo when initiated between 7 and 14 days after birth in ventilated infants born preterm.

STUDY DESIGN

A double-blind, placebo-controlled, randomized trial was conducted in 16 neonatal intensive care units among infants born at <30 weeks of gestation or with a birth weight of <1250 g who were ventilator-dependent in the second week after birth. Three centers performed MRI at term-equivalent age. Brain injury was assessed on MRI using the Kidokoro scoring system and compared between the 2 treatment groups. Both total and regional brain volumes were calculated using an automatic segmentation method and compared using multivariable regression analysis adjusted for baseline variables.

RESULTS

From the 3 centers, 78 infants participated in the study and 59 had acceptable MRI scans (hydrocortisone group, n = 31; placebo group, n = 28). Analyses of the median global brain abnormality score of the Kidokoro score showed no difference between the hydrocortisone and placebo groups (median, 7; IQR, 5-9 vs median, 8, IQR, 4-10, respectively; P = .92). In 39 infants, brain tissue volumes were measured, showing no differences in the adjusted mean total brain tissue volumes, at 352 ± 32 mL in the hydrocortisone group and 364 ± 51 mL in the placebo group (P = .80).

CONCLUSIONS

Systemic hydrocortisone started in the second week after birth in ventilator-dependent infants born very preterm was not found to be associated with significant differences in brain development compared with placebo treatment.

TRIAL REGISTRATION

The SToP-BPD study was registered with the Netherlands Trial Register (NTR2768; registered on 17 February 2011; https://www.trialregister.nl/trial/2640) and the European Union Clinical Trials Register (EudraCT, 2010-023777-19; registered on 2 November 2010; https://www.clinicaltrialsregister.eu/ctr-search/trial/2010-023777-19/NL).

Does faster weight trajectory lead to improved neurodevelopmental outcomes in ELBW infants with bronchopulmonary dysplasia?

OBJECTIVE

Examine the relationship between weight trajectory and 2-year neurodevelopmental outcomes for extremely low birthweight (ELBW) infants with BPD.

STUDY DESIGN

Secondary analysis of infants born from 2010 to 2019. The predictor was BPD severity and the outcome was neurodevelopmental impairment, defined as any Bayley Scales of Infant Development (BSID) III score <70 at 24 months' corrected age. Repeated measures logistic regression was performed.

RESULTS

In total, 5042 infants were included. Faster weight trajectory was significantly associated with a decreased probability of having at least one BSID III score <70 for infants with grade 1-2 BPD (p < 0.0001) and an increased probability of at least one BSID III score <70 for infants with grade 3 BPD (p < 0.009). There was no significant association between weight trajectory and BSID III score <70 for infants with grade 0 BPD.

CONCLUSION

The association between postnatal weight trajectory and neurodevelopmental outcome in this study differs by BPD severity.

[Management of lung diseases under ultrasound monitoring: potential to make bronchopulmonary dysplasia in preterm infants as an avoidable disease]

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in preterm infants. Despite significant progress in the understanding of its etiology, mechanisms, prevention, and treatment, the prognosis remains poor. BPD not only has a high mortality rate but also causes persistent respiratory, neurological, and cardiovascular impairments in survivors. The author's team has successfully prevented the occurrence of BPD by managing neonatal lung diseases under lung ultrasound monitoring for nearly 7 years, opening up a new approach in BPD prevention. This article provides a brief overview of the approach, aiming to facilitate further research and provide more scientifically sound management strategies to prevent or minimize the occurrence of BPD.

Neurodevelopment and healthcare utilisation at age 5-6 years in bronchopulmonary dysplasia: an EPIPAGE-2 cohort study

OBJECTIVE

We aimed to study neurodevelopmental outcomes and healthcare utilisation at age 5-6 years in very preterm children with bronchopulmonary dysplasia (BPD).

DESIGN

Prospective and national population-based study.

SETTING

All the neonatal units in 25 French regions (21 of the 22 metropolitan regions and 4 overseas regions).

PATIENTS

Children born before 32 weeks' gestation in 2011.

INTERVENTIONS

Blind, comprehensive and standardised assessment by trained neuropsychologists and paediatricians at age 5-6 years.

MAIN OUTCOME MEASURES

Overall neurodevelopmental disabilities, behavioural difficulties, developmental coordination disorders, full-scale IQ, cerebral palsy, social interaction disorders, rehospitalisation in the previous 12 months and detailed developmental support.

RESULTS

Of the 3186 children included, 413 (11.7%) had BPD. The median gestational age of children with BPD was 27 weeks (IQR 26.0-28.0) and without BPD was 30 weeks (28.0-31.0). At age 5-6 years, 3150 children were alive; 1914 (60.8%) had a complete assessment. BPD was strongly associated with mild, moderate and severe overall neurodevelopmental disabilities (OR 1.49, 95% CI 1.05 to 2.20; 2.20, 1.41 to 3.42 and 2.71, 1.67 to 4.40). BPD was associated with developmental coordination disorders, behavioural difficulties, lower IQ score as well as rehospitalisation in the last 12 months and developmental support. The association between BPD and cerebral palsy was statistically significant before adjustment but not in adjusted analyses.

CONCLUSIONS

BPD was strongly and independently associated with many neurodevelopmental disabilities. Improving medical and neurodevelopmental management of BPD in very preterm children should be a priority to reduce its long-term consequences.

A review of the effects of early postnatal hyperoxia exposure on the immature brain

Preterm birth is a public health priority worldwide, with approximately 15 million premature babies born each year. Oxygen supplementation is one of the most common interventions for preterm infants. However, prolonged oxygen inhalation at supraphysiological concentrations can lead to the development of bronchopulmonary dysplasia (BPD). In addition to lifelong pulmonary sequelae, clinical evidence suggests that BPD is associated with adverse neurodevelopmental outcomes, such as motor impairment, cognitive impairment, and behavioral deficits, severely affecting the quality of life of preterm infants. However, the mechanisms underlying the combination of neurodevelopmental impairment with BPD remain unclear. Therefore, in recent years, attention has also been focused on the effects of hyperoxia on brain development in preterm infants. In this review, we outline the pathophysiological mechanisms of brain injury caused by developmental hyperoxia exposure in current animal models and briefly describe the pharmacological therapies that may be applicable to the associated brain injury. Overall, more studies are needed to assess the effects of hyperoxia on the immature brain, particularly combined analyses of the lungs and brain in the same experimental setting, to elucidate the potential causes of combined neurodevelopmental impairment in BPD.

Rapamycin attenuates pyroptosis by suppressing mTOR phosphorylation and promoting autophagy in LPS-induced bronchopulmonary dysplasia

PURPOSE/AIM

Bronchopulmonary dysplasia (BPD) is associated with poor survival in preterm infants. Intrauterine infection can aggravate the degree of obstruction of alveolar development in premature infants; however, the pathogenic mechanism remains unclear. In this study, we sought to determine whether pyroptosis could be inhibited by downregulating mammalian target of rapamycin (mTOR) activation and inducing autophagy in BPD-affected lung tissue.

MATERIALS AND METHODS

We established a neonatal rat model of BPD induced by intrauterine infection via intraperitoneally injecting pregnant rats with lipopolysaccharide (LPS). Subsequently, mTOR levels and pyroptosis were evaluated using immunohistochemistry, immunofluorescence, TUNEL staining, and western blotting. The Shapiro-Wilk test was employed to assess the normality of the experimental data. Unpaired t-tests were used to compare the means between two groups, and comparisons between multiple groups were performed using analysis of variance.

RESULTS

Pyroptosis of lung epithelial cells increased in BPD lung tissues. After administering an mTOR phosphorylation inhibitor (rapamycin) to neonatal rats with BPD, the level of autophagy increased, while the expression of autophagy cargo adaptors, LC3 and p62, did not differ. Following rapamycin treatment, NLRP3, Pro-caspase-1, caspase-1, pro-IL-1β, IL-1β, IL-18/Pro-IL-18, N-GSDMD/GSDMD, Pro-caspase-11, and caspase-11 were negatively regulated in BPD lung tissues. The opposite results were observed after treatment with the autophagy inhibitor MHY1485, showing an increase in pyroptosis and a significant decrease in the number of alveoli in BPD.

CONCLUSIONS

Rapamycin reduces pyroptosis in neonatal rats with LPS-induced BPD by inhibiting mTOR phosphorylation and inducing autophagy; hence, it may represent a potential therapeutic for treating BPD.

Risk Factors for Neurodevelopmental Impairment at 2- and 5-Years Corrected Age in Preterm Infants with Established Bronchopulmonary Dysplasia

INTRODUCTION

The objective of this study was to identify risk factors for neurodevelopmental impairment (NDI) at 2- and 5-years corrected age (CA) in a cohort of preterm infants with established bronchopulmonary dysplasia (BPD).

METHODS

This single-center retrospective cohort study included infants born between 2009 and 2016 at a gestational age (GA) <30 weeks with moderate or severe BPD at 36 weeks' postmenstrual age. Perinatal characteristics, (social) demographics, and comorbidities were collected from the electronic patient records. Odds ratios for NDI were calculated with univariate and multivariate logistic regression analyses adjusting for potential confounders.

RESULTS

Of the 602 eligible infants, 123 infants were diagnosed with BPD. NDI was present in 30.3% and 56.1% at 2- and 5-years CA, respectively. The only independent risk factors associated with NDI in the multivariate analyses were birthweight (adjusted odds ratio [aOR] 0.74, 95% CI 0.57-0.95; aOR 0.70, 95% CI 0.54-0.91, respectively), small for GA (SGA) (aOR 3.25, 95% CI 1.09-9.61; aOR 5.44, 95% CI 1.62-18.2, respectively) at both time points, and male gender at 5-years CA (OR 2.49, 95% CI 1.11-5.57).

CONCLUSION

Birthweight and SGA are independent risk factors for NDI at 2- and 5-years CA and male gender at 5-years CA in preterm infants with BPD. In contrast, well-known other risk factors for NDI in the general population of preterm infants, such as GA, maternal education, and neonatal comorbidities were not independently associated with NDI.

Towards a harmonized bronchopulmonary dysplasia definition: a study protocol for an international Delphi procedure

INTRODUCTION

Bronchopulmonary dysplasia (BPD) remains the most common complication of preterm birth with lifelong consequences. Multiple BPD definitions are currently used in daily practice. Uniformity in defining BPD is important for clinical care, research and benchmarking. The aim of this Delphi procedure is to determine what clinicians and researchers consider the key features for defining BPD. With the results of this study, we hope to advance the process of reaching consensus on the diagnosis of BPD.

METHODS AND ANALYSIS

A Delphi procedure will be used to establish why, when and how clinicians propose BPD should be diagnosed. This semi-anonymous iterative technique ensures an objective approach towards gaining these insights. An international multidisciplinary panel of clinicians and researchers working with preterm infants and/or patients diagnosed with BPD will participate. Steering committee members will recruit potential participants in their own region or network following eligibility guidelines to complete a first round survey online. This round will collect demographic information and opinions on key features of BPD definitions. Subsequent rounds will provide participants with the results from the previous round, for final acceptance or rejection of key features. Statements will be rated using a 5-point Likert scale. After completing the Delphi procedure, an (online) consensus meeting will be organised to discuss the results.

ETHICS AND DISSEMINATION

For this study, ethical approval a waiver has been provided. However, all participants will be asked to provide consent for the use of personal data. After the Delphi procedure is completed, it will be published in a peer-reviewed journal and disseminated at international conferences.

Emerging role of metabolic reprogramming in hyperoxia-associated neonatal diseases

Oxygen therapy is common during the neonatal period to improve survival, but it can increase the risk of oxygen toxicity. Hyperoxia can damage multiple organs and systems in newborns, commonly causing lung conditions such as bronchopulmonary dysplasia and pulmonary hypertension, as well as damage to other organs, including the brain, gut, and eyes. These conditions are collectively referred to as newborn oxygen radical disease to indicate the multi-system damage caused by hyperoxia. Hyperoxia can also lead to changes in metabolic pathways and the production of abnormal metabolites through a process called metabolic reprogramming. Currently, some studies have analyzed the mechanism of metabolic reprogramming induced by hyperoxia. The focus has been on mitochondrial oxidative stress, mitochondrial dynamics, and multi-organ interactions, such as the lung-gut, lung-brain, and brain-gut axes. In this article, we provide an overview of the major metabolic pathway changes reported in hyperoxia-associated neonatal diseases and explore the potential mechanisms of metabolic reprogramming. Metabolic reprogramming induced by hyperoxia can cause multi-organ metabolic disorders in newborns, including abnormal glucose, lipid, and amino acid metabolism. Moreover, abnormal metabolites may predict the occurrence of disease, suggesting their potential as therapeutic targets. Although the mechanism of metabolic reprogramming caused by hyperoxia requires further elucidation, mitochondria and the gut-lung-brain axis may play a key role in metabolic reprogramming.

The role of oxygen in the development and treatment of bronchopulmonary dysplasia

Oxygen (O2) is crucial for both the development and treatment of one of the most important consequences of prematurity: bronchopulmonary dysplasia (BPD). In fetal life, the hypoxic environment is important for alveolar development and maturation. After birth, O2 becomes a double-edged sword. While O2 is needed to prevent hypoxia, it also causes oxidative stress leading to a plethora of morbidities, including retinopathy and BPD. The advent of continuous O2 monitoring with pulse oximeters has allowed clinicians to recognize the narrow therapeutic margins of oxygenation for the preterm infant, but more knowledge is needed to understand what these ranges are at different stages of the preterm infant's life, including at birth, in the neonatal intensive care unit and after hospital discharge. Future research, especially in innovative technologies such as automated O2 control and remote oximetry, will improve the understanding and treatment of the O2 needs of infants with BPD.

Protocol for a randomized controlled trial to evaluate a year-long (NICU-to-home) evidence-based, high dose physical therapy intervention in infants at risk of neuromotor delay

INTRODUCTION

Developmental disabilities and neuromotor delay adversely affect long-term neuromuscular function and quality of life. Current evidence suggests that early therapeutic intervention reduces the severity of motor delay by harnessing neuroplastic potential during infancy. To date, most early therapeutic intervention trials are of limited duration and do not begin soon after birth and thus do not take full advantage of early neuroplasticity. The Corbett Ryan-Northwestern-Shirley Ryan AbilityLab-Lurie Children's Infant Early Detection, Intervention and Prevention Project (Project Corbett Ryan) is a multi-site longitudinal randomized controlled trial to evaluate the efficacy of an evidence-based physical therapy intervention initiated in the neonatal intensive care unit (NICU) and continuing to 12 months of age (corrected when applicable). The study integrates five key principles: active learning, environmental enrichment, caregiver engagement, a strengths-based approach, and high dosage (ClinicalTrials.gov identifier NCT05568264).

METHODS

We will recruit 192 infants at risk for neuromotor delay who were admitted to the NICU. Infants will be randomized to either a standard-of-care group or an intervention group; infants in both groups will have access to standard-of-care services. The intervention is initiated in the NICU and continues in the infant's home until 12 months of age. Participants will receive twice-weekly physical therapy sessions and caregiver-guided daily activities, assigned by the therapist, targeting collaboratively identified goals. We will use various standardized clinical assessments (General Movement Assessment; Bayley Scales of Infant and Toddler Development, 4th Edition (Bayley-4); Test of Infant Motor Performance; Pediatric Quality of Life Inventory Family Impact Module; Alberta Infant Motor Scale; Neurological, Sensory, Motor, Developmental Assessment; Hammersmith Infant Neurological Examination) as well as novel technology-based tools (wearable sensors, video-based pose estimation) to evaluate neuromotor status and development throughout the course of the study. The primary outcome is the Bayley-4 motor score at 12 months; we will compare scores in infants receiving the intervention vs. standard-of-care therapy.

Modified lung ultrasound score for bronchopulmonary dysplasia predicts late respiratory outcomes in preterm infants

OBJECTIVE

Lung ultrasound (LUS) is a useful and radiation-free diagnostic tool for predicting bronchopulmonary dysplasia, which is a risk factor for late respiratory disease. However, data on the relationship of LUS with late respiratory disease was scarce. This study aims to determine whether LUS is associated with late respiratory disease during early childhood.

METHODS

This prospective cohort study enrolled preterm infants born before 32 weeks of gestation. LUS was performed at 36 weeks' postmenstrual age. The predictive values of a modified lung ultrasound (mLUS) score based on eight standard sections were assessed to predict late respiratory disease, defined as a physician diagnosis of bronchopulmonary dysplasia deterioration, asthma, reactive airway disease, bronchiolitis, pneumonia, or respiratory-related hospitalization during the first 2 years of life.

RESULTS

A total of 94 infants completed follow-up, of whom 74.5% met the late respiratory disease criteria. The mLUS scores were significantly associated with late respiratory disease (adjusted odds ratio: 1.23, CI: 1.10-1.38, p < 0.001). The mLUS scores also well predicted late respiratory disease (AUC = 0.820, 95% CI: 0.733-0.907). These scores were superior to the classic lung ultrasound score (p = 0.02) and as accurate as the modified NICHD-defined bronchopulmonary dysplasia classification (p = 0.91). A mLUS score ≥14 was the optimal cutoff point for predicting late respiratory disease.

CONCLUSION

The modified lung ultrasound score correlates significantly with late respiratory disease and well predicts it in preterm infants during the first 2 years of life.

Effect of biomedical complications on very and extremely preterm children's language

Introduction

Very and extremely preterm children have been found to show delays in the development of language in early years. In some investigations, however, a rigorous control of biomedical complications, such as Periventricular Leukomalacia (PVL), Intraventricular Hemorrhage (IVH) or Bronchopulmonary Dysplasia (BPD), does not always exist. For that reason, a confounding effect of low gestational age and biomedical complications may lead to erroneous conclusions about the effect of gestational age.

Methods

In this investigation we compare language development [use of words, sentence complexity and mean length of the three longest utterances (MLU3)] of three groups of Chilean children at 24 months of age (corrected age for preterm children). The first group was composed of 42 healthy full-term children (Full term group: FT), the second group of 60 preterm children born below 32 gestational weeks without medical complications (low risk preterm group: LRPT), and the third group was composed of 64 children below 32 gestational weeks who had medical complications (High risk preterm group: HRPT). The three groups were similar in terms of gender distribution, maternal education, and socio-economic environment. The instrument used to assess language was the Communicative Development Inventories (CDI). In addition, the Ages and Stages Questionnaire-3 (ASQ-3) was also used to assess other developmental dimensions.

Results

The results indicate that HRPT and LRPT children obtained significantly lower results than the FT group in the three language measures obtained through the CDI. No significant differences were observed between the HRPT and the LRPT groups, although the HRPT obtained the lowest results in the three CDI measures. The results obtained through the administration of the ASQ-3 confirm the delay of both preterm groups in communicative development when compared to the FT group. No significant differences between the FT and the PT groups were observed in gross motor, fine motor and problem solving dimensions of the ASQ-3. The LRPT group obtained results that were significantly higher than those of the FT group and the HRPT group in gross motor development.

Discussion

These results seem to indicate that the area of language development is particularly influenced by very or extremely low gestational age.

Bronchopulmonary dysplasia and neurobehavioural outcomes at birth and 2 years in infants born before 30 weeks

OBJECTIVE

To identify neurobehavioural risks in preterm infants with bronchopulmonary dysplasia (BPD) prior to hospital discharge.

DESIGN AND PATIENTS

Longitudinal study of 676 newborns born before 30 weeks of gestation.

SETTING

Nine university NICUs affiliated with six universities. All were Vermont Oxford Network (VON) participants.

PATIENTS AND INTERVENTIONS

Infants were enrolled in the Neonatal Neurobehavior and Outcomes in Very Preterm Infants Study from April 2014 to June 2016. Prospective medical record reviews, VON definitions and criteria, and maternal interviews were used to collect maternal and neonatal medical variables and socioenvironmental data.

MAIN OUTCOME MEASURES

NICU Network Neurobehavioral Scale (NNNS) at the time of hospital discharge; Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) and Gross Motor Function Classification System at 2 years' corrected age.

RESULTS

Infants with moderate/severe BPD were less attentive (Wald χ2 9.68, p=0.008), more lethargic (Wald χ2 9.91, p=0.007), with increased non-optimal reflexes (Wald χ2 7.37, p=0.025). Infants with moderate/severe BPD were more likely to have Bayley-III language and motor scores <85 (adjusted OR (aOR) 1.74, 95% CI 1.06 to 2.85, and aOR 2.06, 95% CI 1.10 to 3.85). Infants with both moderate/severe and mild BPD were more likely to have a cerebral palsy diagnosis (aOR 2.96, 95% CI 1.34 to 6.54, and aOR 2.81, 95% CI 1.32 to 5.99).

CONCLUSIONS

BPD severity presents risks for poor neurodevelopment at NICU discharge and at age 2 years. Early identification of poorly regulated behaviour can provide critical information for early preventive and targeted interventions with potential to improve long-term outcomes.

AMPK-driven Macrophage Responses Are Autophagy Dependent in Experimental Bronchopulmonary Dysplasia

The pathogenesis of bronchopulmonary dysplasia (BPD) remains incompletely understood. Recent studies suggest insufficient AMP-activated protein kinase (AMPK) activation as a potential cause of impaired autophagy in rodent and nonhuman primate models of BPD. Impaired autophagy is associated with enhanced inflammatory signaling in alveolar macrophages (AMs) and increased severity of murine BPD induced by neonatal hyperoxia exposure. The goal of this study was to determine the role of autophagy and AMPK activation in macrophage responses in murine BPD. C57BL/6J mice were exposed to neonatal hyperoxia starting on postnatal day (P)1 and treated with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) between P3 and P6. Mice were euthanized on P7, and markers of AMPK activation and autophagy were assessed by immunoblotting. Alveolarization was assessed using radial alveolar counts, mean linear intercept measurements, and quantification of alveolar septal myofibroblasts. Relative mRNA expression of M1-like and M2-like genes was assessed in AMs isolated from BAL fluid from wild-type, LysMCre--Becn1fl/fl, and LysMCre+-Becn1fl/fl mice after neonatal hyperoxia exposure. AICAR treatment resulted in AMPK activation and induction of autophagic activity in whole-lung and BAL cell lysates and attenuated hyperoxia-induced alveolar simplification in neonatal lungs. AICAR-treated control but not Beclin1-deficient AMs demonstrated significantly decreased expression of M1-like markers and significantly increased expression of M2-like markers. In conclusion, pharmacologic activation of AMPK by AICAR resulted in induction of autophagy and played a protective role, at least in part, through attenuation of proinflammatory signaling in AMs via autophagy-dependent mechanisms in a murine model of BPD.

The prevention and management strategies for neonatal chronic lung disease

INTRODUCTION

Survival from even very premature birth is improving, but long-term respiratory morbidity following neonatal chronic lung disease (bronchopulmonary dysplasia (BPD)) has not reduced. Affected infants may require supplementary oxygen at home, because they have more hospital admissions particularly due to viral infections and frequent, troublesome respiratory symptoms requiring treatment. Furthermore, adolescents and adults who had BPD have poorer lung function and exercise capacity.

AREAS COVERED

Antenatal and postnatal preventative strategies and management of infants with BPD. A literature review was undertaken using PubMed and Web of Science.

EXPERT OPINION

There are effective preventative strategies which include caffeine, postnatal corticosteroids, vitamin A, and volume guarantee ventilation. Side-effects, however, have appropriately caused clinicians to reduce use of systemically administered corticosteroids to infants only at risk of severe BPD. Promising preventative strategies which need further research are surfactant with budesonide, less invasive surfactant administration (LISA), neurally adjusted ventilatory assist (NAVA) and stem cells. The management of infants with established BPD is under-researched and should include identifying the optimum form of respiratory support on the neonatal unit and at home and which infants will most benefit in the long term from pulmonary vasodilators, diuretics, and bronchodilators.

Effect of systemic hydrocortisone in ventilated preterm infants on parent-reported behavioural outcomes at 2 years' corrected age: follow-up of a randomised clinical trial

OBJECTIVE

To report the parent-reported behavioural outcomes of infants included in the Systemic Hydrocortisone To Prevent Bronchopulmonary Dysplasia in preterm infants study at 2 years' corrected age (CA).

DESIGN

Randomised placebo-controlled trial.

SETTING

Dutch and Belgian neonatal intensive care units.

PATIENTS

Infants born <30 weeks' gestation and/or birth weight <1250 g, and ventilator dependent in the second week of life.

INTERVENTION

Infants were randomly assigned to a 22-day course of systemic hydrocortisone (cumulative dose 72.5 mg/kg; n=182) or placebo (n=190).

MAIN OUTCOME MEASURES

Parent-reported behavioural outcomes at 2 years' CA assessed with the Child Behavior Checklist (CBCL 1½-5).

RESULTS

Parents completed the CBCL of 183 (70% (183/262)) infants (hydrocortisone group, n=96; placebo group, n=87). Multiple imputation was used to account for missing data. Infants with critically elevated T-scores (>55) were found in 22.9%, 19.1% and 29.4% of infants for total, internalising and externalising problems, respectively; these scores were not significantly different between groups (mean difference -1.52 (95% CI -4.00 to 0.96), -2.40 (95% CI -4.99 to 0.20) and -0.81 (95% CI -3.40 to 1.77), respectively). In the subscales, we found a significantly lower T-score for anxiety problems in the hydrocortisone group (mean difference -1.26, 95% CI -2.41 to -0.12).

CONCLUSION

This study found high rates of behaviour problems at 2 years' CA following very preterm birth, but these problems were not associated with hydrocortisone treatment initiated between 7 and 14 days after birth in ventilated preterm infants.

TRIAL REGISTRATION NUMBER

NTR2768; EudraCT 2010-023777-19.

Definitions of Bronchopulmonary Dysplasia: Which One Should We Use?

OBJECTIVE

To assess the clinical applicability of the current definitions of bronchopulmonary dysplasia (BPD) and their ability to predict subsequent respiratory outcomes.

STUDY DESIGN

In this retrospective cohort study, data were collected from 104 preterm infants (mean gestational age, 25.8 weeks) diagnosed with BPD between 2010 and 2018 at a single tertiary care center. The infants were classified according to the following definitions: 2001 National Institute of Child Health and Human Development (NICHD), 2017 Canadian Neonatal Network (CNN), 2018 NICHD, and 2019 Neonatal Research Network (NRN). Logistic regression and the area under the receiver operating characteristic curve (AUC) were used to assess the predictive ability of each definition on mortality or severe respiratory morbidity at 18-24 months of age.

RESULTS

All patients could be adequately classified by each definition, except for the 2001 NICHD definition, in which 11.4% were unclassifiable. The prevalence of BPD was 49% by the 2017 CNN definition and 70% by the 2018 NICHD and 2019 NRN definitions. The best regression model was the one that included the 2018 NICHD definition, which had an accuracy of 85.6% and a significantly higher AUC compared with the 2001 NICHD (0.891 vs 0.824; P = .015) and 2017 CNN (0.891 vs 0.811; P = .036) definitions, but not compared with the 2019 NRN definition (0.891 vs 0.833; P = .09).

CONCLUSIONS

The current definitions of BPD showed a good predictive ability for mid-term respiratory outcomes, with the highest ability for the 2018 NICHD definition. Further studies are needed to establish the most appropriate definition of BPD.

Neurocognitive outcomes at age 5 years after prophylactic hydrocortisone in infants born extremely preterm

AIM

To assess the 5-year neurocognitive outcomes of children born extremely preterm exposed to prophylactic hydrocortisone to improve survival without bronchopulmonary dysplasia.

METHOD

This was a prespecified secondary analysis of the PREMILOC clinical trial (trial registration: EudraCT no. 2007-002041-20, NCT00623740). The primary outcome was full-scale IQ based on the Wechsler Preschool and Primary Scale of Intelligence.

RESULTS

Among 109 surviving children recruited at the Robert Debré Children's Hospital, Paris, outcome data were available for 42 out of 56 infants (75%) in the group treated with hydrocortisone and 41 out of 53 (77%) in the placebo group. Mean scores were not significantly different between the two groups on full-scale IQ (hydrocortisone: 91.9 [SD = 13.9], placebo: 86.3 [SD = 15.4]; mean difference = 5.7, 95% confidence interval [CI] = -1.0 to 12.3, p = 0.10); however, working memory and retention ability were significantly better in the group treated with hydrocortisone. In a multivariate logistic regression including potential confounding variables, hydrocortisone treatment was significantly associated with a greater chance to survive at 5 years of age with a full-scale IQ equal to or greater than 90 compared to placebo (adjusted odds ratio = 4.26, 95% CI = 1.47-12.36, p = 0.008).

INTERPRETATION

This exploratory analysis provides reassuring data regarding the long-term neurodevelopmental safety of prophylactic hydrocortisone in infants born extremely preterm.

Bronchopulmonary dysplasia is not related to neurofilament light for neuroaxonal damage in preterm infants

BACKGROUND

Neurofilament light (NfL) has been identified as a biomarker for neuroaxonal damage in preterm infants, but its relation with bronchopulmonary dysplasia (BPD) has not been established. We hypothesized that BPD is associated with increased NfL levels at an early stage, indicative of early neuroaxonal damage.

METHODS

We included preterm infants born <30 weeks of gestation for assessment of NfL levels from cord blood and blood obtained at postnatal days 3, 7, 14, and 28. We used linear regression analysis to compare NfL levels between infants with moderate/severe BPD and infants with no/mild BPD, and linear mixed model analysis to compare the effect of time on NfL levels between groups.

RESULTS

Sixty-seven infants with a gestational age (GA) of 27 ± 1.3 weeks were included for analysis, of whom 19 (28%) developed moderate/severe BPD. Although NfL levels were higher at every time point in infants with BPD, statistical significance was lost after adjustment for GA, small for gestational age (SGA) and intraventricular hemorrhage (IVH). Groups did not differ in NfL change over time.

CONCLUSIONS

The positive association between BPD and NfL in the first weeks of life could be explained by GA, SGA and IVH rather than by development of BPD.

IMPACT

Neurofilament light chain (NfL) is a known biomarker for neuroaxonal damage. Biomarkers for brain damage during the first weeks of life in preterm infants developing BPD are lacking. NfL levels obtained during the first weeks of life did not differ between infants with and without BPD in analyses adjusted for GA, SGA, and IVH.

Comparison of definitions of bronchopulmonary dysplasia to reflect the long-term outcomes of extremely preterm infants

Survivors of neonatal bronchopulmonary dysplasia (BPD) have persistent respiratory, neurodevelopmental, and growth impairment over the first few years of life and later childhood, which represents an emerging burden for health systems. Therefore, there is an increasing need for a new definition and grading system of BPD that predicts long-term outcomes of high-risk infants who need timely and proper intervention to improve outcomes. We compared new definitions of BPD (National Institute of Child Health and Human Development [NICHD] 2018 and Neonatal Research Network [NRN] 2019) to the original NICHD 2001 definition at 3 years of age using a nationwide cohort of extreme preterm infants. New definitions and severity grading were clearly related to respiratory, neurodevelopmental, and growth impairments at 3 years of age and at 18-24 months corrected age (CA), whereas the original NICHD 2001 definition was not. Furthermore, the negative effect of BPD on growth was ameliorated at 3 years of age compared to 18-24 months CA. However, the negative effect of BPD in neonates on the respiratory system and neurodevelopment persisted at 3 years of age. These new definitions should be adopted to identify high-risk infants and improve long-term outcomes by exact diagnosis and BPD severity classification.

Increased transmissibility of SARS-CoV-2 alpha variant (B.1.1.7) in children: three large primary school outbreaks revealed by whole genome sequencing in the Netherlands

Background

Variant of concern (VOC) SARS-CoV-2 alpha variant (B.1.1.7) was the dominant strain in the Netherlands between March 2021–June 2021. We describe three primary school outbreaks due to the alpha variant using whole genome sequencing with evidence of large-scale transmission among children, teachers and their household contacts.

Method

All outbreaks described were investigated by the South Limburg Public Health Service, the Netherlands. A case was defined as an individual with a real-time polymerase chain reaction test or antigen test positive for SARS-CoV-2. Whole genome sequencing was performed on random samples from at least one child and one teacher of each affected class.

Results

Peak attack rates in classes were 53%, 33% and 39%, respectively. Specific genotypes were identified for each school across a majority of affected classes. Attack rates were high among staff members, likely to promote staff-to-children transmission. Cases in some classes were limited to children, indicating child-to-child transmission. At 39%, the secondary attack rate (SAR) in household contacts of infected children was remarkably high, similar to SAR in household contacts of staff members (42%). SAR of household contacts of asymptomatic children was only 9%.

Conclusion

Our findings suggest increased transmissibility of the alpha variant in children compared to preceding non-VOC variants, consistent with a substantial rise in the incidence of cases observed in primary schools and children aged 5–12 since the alpha variant became dominant in March 2021. Lack of mandatory masking, insufficient ventilation and lack of physical distancing also probably contributed to the school outbreaks. The rise of the delta variant (B.1.617.2) since July 2021 which is estimated to be 55% more transmissible than the alpha variant, provides additional urgency to adequate infection prevention in school settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07623-9.