New BPD-prevalence and risk factors for bronchopulmonary dysplasia/mortality in extremely low gestational age infants ≤28 weeks

Systemic heparin administration impairs lung development in neonatal mice

Preterm infants born in the saccular stage of lung development are at risk for developing bronchopulmonary dysplasia (BPD). Oxygen toxicity and volutrauma are identified as major contributors of BPD. Despite mitigation of these risks preterm infants continue to be affected by chronic lung disease. Heparin is commonly administered to preterm infants and is known to interfere with angiogenesis, a critical element of lung development. We previously demonstrated, in a murine model, that compensatory lung growth after left pneumonectomy is inhibited by heparin administration. Based on these results, we hypothesized that heparin would interfere with lung development in neonatal mice, which are born during the saccular phase of lung development. Newborn C57BL/6J mice received either therapeutic unfractionated heparin (UFH), low molecular weight heparin (LMWH) or normal saline (control) for the first week of life. At one month, both UFH and LMWH produced an emphysematous lung phenotype. Late administration of heparin, after the saccular phase did not impact lung function or growth. This data establishes the negative effects of UFH and LMWH during the critical period of postnatal lung development. Based on this work, clinical studies on the impact of heparin on lung development of newborn and preterm infants are warranted.

The interplay between birth weight and intraventricular hemorrhage in very preterm neonates-a retrospective cohort study

BACKGROUND

Intraventricular hemorrhage (IVH) most commonly occurs in infants born very preterm (<32 weeks' gestation). There are mixed findings on whether infants small for gestational age (SGA) or with suspected fetal growth restriction (FGR) are at higher risk for IVH. Understanding the relationship between SGA or FGR and IVH is critical to inform clinical care.

OBJECTIVE

The primary aim was to determine the rates of IVH in very preterm newborns, with SGA or suspected FGR, and to stratify for severity of both FGR and IVH. The secondary aim was to identify risk factors for IVH in a large contemporary cohort.

STUDY DESIGN

A population-based retrospective cohort study using data from the Australian and New Zealand Neonatal Network. Participants were babies born before 32 weeks' gestation (22-31 weeks + 6 days gestation) between 2014 and 2019 inclusive. The primary outcomes were IVH and severity of IVH. Small babies were classified as being SGA (SGA; birth weight <10th percentile), suspected FGR (birth weight <10th and ≥3rd birth weight percentile and abnormal antenatal ultrasound), or severe FGR (birth weight <3rd percentile). Multivariate regression was then performed, adjusting for potential maternal and fetal confounders to determine the association between FGR and IVH.

RESULTS

20,551 very preterm newborns were included in the study with a median gestational age (25th, 75th) of 29 (27, 30) weeks gestation and birth weight of 1201 (383.9) grams. The incidence of any IVH was 20.02% (n=4115) and increased with decreasing gestation at birth (10% of infants born at 31 weeks had IVH compared with 70% of infants born at 22 weeks). The rate of severe IVH (Grade 3 or 4) was 3.23%. In this cohort, 7.7% were SGA (n=1583) and 6.23% (n=1281) of babies had suspected early-onset FGR. The incidence of SGA was reduced in babies with IVH (6.0% vs 8.1%, respectively, aOR, 0.82; 95% CI 0.68-0.97). Similarly, suspected FGR was significantly lower in infants with IVH (any grade) compared to those without (2.5% vs 4.6%, respectively, adjusted odds ratio (aOR), 0.69; 95% CI 0.54-0.89). Further, there was a negative association between SGA (aOR, 0.80; 95% CI 0.67-0.95) and FGR (aOR 0.69; 95% CI 0.54-0.88) and the severity of IVH. Severe FGR (<3rd birth weight percentile) was not associated with either the presence (1.9% with IVH, vs 2.1% without IVH, aOR, 0.86; 95% CI 0.64-1.16) or severity of IVH (aOR, 0.85; 95% CI 0.63-1.14).

CONCLUSION

This large retrospective cohort study identified that in very preterm infants born with a median gestational age at birth of 29 weeks and who survive to the neonatal unit, the presence of SGA or suspected FGR is associated with a reduced rate of IVH, compared to infants without SGA/FGR. Future studies should directly assess whether placental insufficiency prevents the development of IVH, so that novel neuroprotective strategies for the very preterm infant can be implemented.

Sample entropy of oxygen saturation in preterm infants

Bronchopulmonary dysplasia (BPD) is the most common respiratory complication after preterm birth. Early preventive measures are important to reduce further damage on lung tissue. Thus, early discrimination between infants with and without BPD is of high importance. A low sample entropy (SampEn) of time series of the oxyhemoglobin saturation (SpO2-SampEn for short) is associated with an increased risk of hypoxemic events in neonates. We hypothesized that preterm infants have a lower SpO2-SampEn compared to term infants. Moreover, that infants with BPD have a lower SpO2-SampEn compared to those without BPD. Preterm infants < 32 w gestation and healthy term infants were eligible for study. We recorded SpO2 over 90 min through the clinical monitoring system with a sampling frequency of 0.98 Hz and calculated the SpO2-SampEn at 32 w postmenstrual age (PMA), 36 w PMA, and at discharge. We included 95 term and 180 preterm infants, of whom 44 (24.4%) developed BPD. SpO2-SampEn was lower in preterm infants compared to term infants. SpO2-SampEn was lower in infants with BPD compared to infants without BPD at 32 w PMA. However, gestational age was the only predictor of SampEn at 32 w PMA. This difference between infants with and without BPD was no longer present at 36 w PMA and discharge. SpO2-SampEn can be utilized to discriminate between preterm and term infants and between preterm infants with and without BPD. However, confounding factors such as caffeine therapy, gestational age and the natural boundary of 100% of SpO2 values have to be considered.

Clinical analysis and predictive value of early serum lipid levels in very premature and extremely preterm infants with bronchopulmonary dysplasia: a 4 years retrospective study

BACKGROUND

Lipid metabolism plays an important role in fetal growth and development, but its role in lung maturation is currently unknown. We investigated the relationship between early serum lipid levels and clinical characteristics of bronchopulmonary dysplasia (BPD) in very preterm and extremely preterm infants.

METHODS

This study analyzed the clinical data of preterm infants with gestational age ≤ 32 weeks between January 2020 and February 2024, while clinical risk factors, maternal comorbidities, treatment methods and prognosis were retrospectively reviewed for subjects (n = 341) recruited from neonatal intensive care unit (NICU).

RESULTS

Of 228 BPD and 113 non-BPD extremely preterm infants, univariate analysis found that triglyceride (TG, P < 0.01) and high-density lipoprotein (HDL, P = 0.04) levels on the first day of admission were significantly lower in BPD infants, however, apolipoprotein A1 levels were higher than those in the non-BPD group (P < 0.01). Multivariable model further revealed that apolipoprotein A1 (Apo-A1) was a dominant determinant (OR 6.55, 95% CI 2.61,6.12). Regarding perinatal risk factors, maternal gestational hypertension was a risk factor for the morbidity of BPD (P = 0.04), while prenatal hormone exposure displayed a positive performance (P = 0.01). Kaplan-Meier curve showed no statistical difference in survival between low and normal serum lipid level groups (P > 0.05).

CONCLUSIONS

TG, HDL, Apo-A1 levels provide an insight risk and prognostication stratification in very preterm BPD infants, thus, neonatologists should emphasize high-risk features and optimize preventive therapy.

Characterizing the Role of Left Ventricular Indices and Biventricular Interaction in Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension in Extreme Prematurity

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is a common respiratory morbidity in preterm infants. The onset of pulmonary hypertension leads to worse respiratory outcomes. The contribution of left ventricular diastolic dysfunction in BPD-PH is well reported. We evaluated the serial left ventricular function and possible ventricular interdependence among BPD-PH.

METHODS

This is a single-center, prospective observational study. Infants <28 weeks of gestation are included.

RESULTS

Eighty infants were enrolled. The incidence of BPD-PH was 23%. The BPD-PH group had a high incidence of hemodynamically significant ductus arteriosus (83% vs. 56%, p < 0.018), longer oxygen days (96.2 ± 68.1 vs. 59.35 ± 52, p < 0.008), and prolonged hospital stay (133.8 ± 46 vs. 106.5 ± 38 days, p < 0.005). Serial tissue Doppler imaging showed prolonged left ventricle (LV) isovolumetric contraction time (IVCT) (31.05 ± 3.3 vs. 26.8 ± 4.4 ms, p < 0.001) and myocardial performance index (MPI) (0.43 ± 0.03 vs. 0.37 ± 0.04, p < 0.001) from 33 weeks. The changes in IVCT (35.9 ± 6.7 vs. 27.9 ± 4.5 ms, p < 0.001), isovolumetric relaxation time (IVRT) (50 ± 6.5 vs. 39.9 ± 5.8 ms, p < 0.001), and MPI (0.48 ± 0.05 vs. 0.36 ± 0.03, p < 0.001) persisted at 36 weeks. The receiver operator characteristic curve showed LV MPI >40 has 83% sensitivity and 65% specificity (AUC: 0.77, p < 0.001) in the diagnosis of PH. The BPD-PH group had a higher LV E/E' ratio (13.1 ± 4.4 vs. 11.4 ± 3.4, p < 0.02). Pearson correlation test showed a moderate positive correlation between RV MPI and LV MPI (r = 0.585, p < 0.001).

CONCLUSIONS

Significant LV diastolic dysfunction was observed in BPD-PH. This is the first study to show biventricular strain and possible ventricular interdependence in BPD-PH. The prolonged LV IVRT and MPI may be a novel echocardiographic indicator of BPD-PH.

Fingolimod, a sphingosine-1-phosphate receptor modulator, prevents neonatal bronchopulmonary dysplasia and subsequent airway remodeling in a murine model

Neonatal bronchopulmonary dysplasia (BPD) is associated with alveolar simplification and airway remodeling. Airway remodeling leads to deformation of airways characterized by peribronchial collagen deposition and hypertrophy of airway smooth muscle, which contribute to the narrowing of airways. Poorly developed lungs contribute to reduced lung function that deteriorates with the passage of time. We have earlier shown that sphingosine kinase 1 (SPHK 1)/sphingosine-1-phosphate (S1P)/S1P receptor1 (S1PR1) signaling plays a role in the pathogenesis of BPD. In this study, we investigated the role of fingolimod or FTY720, a known S1PR1 modulator approved for the treatment of multiple sclerosis in the treatment of BPD. Fingolimod promotes the degradation of S1PR1 by preventing its recycling, thus serving as the equivalent of an inhibitor. Exposure of neonatal mice to hyperoxia enhanced the expression of S1PR1 in both airways and alveoli as compared with normoxia. This increased expression of S1PR1 in the airways persisted into adulthood, accompanied by airway remodeling and airway hyperreactivity (AHR) after neonatal hyperoxia. Intranasal fingolimod at a much lower dose compared with the intraperitoneal route of administration during neonatal hyperoxia improved alveolarization in neonates and reduced airway remodeling and AHR in adult mice associated with improved lung function. The intranasal route was not associated with the lymphopenia seen with the intraperitoneal route of administration of the drug. An increase in S1PR1 expression in the airways was associated with an increase in the expression of enzyme lysyl oxidase (LOX) in the airways following hyperoxia, which was suppressed by fingolimod. This association warrants further investigation.NEW & NOTEWORTHY The role of the S1P receptor1 modulator, fingolimod, as an FDA-approved drug in preventing the recurrence of multiple sclerosis is established. Fingolimod prevented bronchopulmonary dysplasia (BPD) and its sequela of airway remodeling in a neonatal murine model. This protection was associated with the downregulation of lysyl oxidase signaling pathway. Fingolimod could be repurposed for the therapy of BPD.

Impact of implementation of 2019 European respiratory distress syndrome guidelines on bronchopulmonary dysplasia in very preterm infants

BACKGROUND

To evaluate the impact of implementation of 2019 European respiratory distress syndrome (RDS) guidelines on the incidence of bronchopulmonary dysplasia (BPD).

METHOD

We retrospectively collected the clinical data of very preterm infants (VPIs) born before 32 gestational weeks from January 1st 2018 to December 31st 2021. VPIs were divided into group A and group B according to their birth date which was before or at/after January 1st 2020, when the 2019 European RDS guidelines were introduced. BPD is considered as primary outcome. We statistically analyzed all the data, and we compared the general characteristics, ventilation support, medication, nutrition and the outcomes between the two groups.

RESULTS

A total of 593 VPIs were enrolled, including 380 cases in group A and 213 cases in group B. There were no statistic differences regarding to gender ratio, gestational age, birth weight and delivery mode between the two groups. Compared with group A, group B showed higher rate of antenatal corticosteroid therapy (75.1% vs. 65.5%). The improvement of ventilation management in these latter patients included lower rate of invasive ventilation (40.4% vs. 50.0%), higher rate of volume guarantee (69.8% vs. 15.3%), higher positive end expiratory pressure (PEEP) [6 (5, 6) vs. 5 (5, 5) cmH2O] and higher rate of synchronized nasal intermittent positive pressure ventilation (sNIPPV) (36.2% vs. 5.6%). Compared with group A, group B received higher initial dose of pulmonary surfactant [200 (160, 200) vs. 170 (130, 200) mg/Kg], shorter antibiotic exposure time [13 (7, 23) vs. 17 (9, 33) days], more breast milk (86.4% vs. 70.3%) and earlier medication for hemodynamically significant patent ductus arteriosus (hsPDA) treatment [3 (3, 4) vs. 8 (4, 11) days] (p < 0.05). As the primary outcome, the incidence of BPD was significantly decreased (16.9% vs. 24.2%) (p < 0.05), along with lower extrauterine growth retardation (EUGR) rate (39.0% vs. 59.7%), while there were no statistic differences regarding to other secondary outcomes, including mortality, intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), retinopathy of preterm (ROP) and necrotizing enterocolitis (NEC). However, in the subgroups of infants less than 28 gestational weeks or infants less than 1,000 g, the incidence of BPD was not significantly decreased (p > 0.05).

CONCLUSIONS

After implementation of 2019 European RDS guidelines, the overall incidence of BPD was significantly decreased in VPIs. Continuous quality improvement is still needed in order to decrease the incidence of BPD in smaller infants who are less than 28 gestational weeks or less than 1,000 g.

Lung Recruitment Before Surfactant Administration in Extremely Preterm Neonates: 2-Year Follow-Up of a Randomized Clinical Trial

IMPORTANCE

A multicenter randomized clinical trial (RCT) showed a lung recruitment maneuver using high-frequency oscillatory ventilation just before surfactant administration (ie, intubate-recruit-surfactant-extubate [IN-REC-SUR-E]) improved the efficacy of treatment compared with the standard intubate-surfactant-extubate (IN-SUR-E) technique without increasing the risk of adverse neonatal outcomes.

OBJECTIVE

To examine follow-up outcomes at corrected postnatal age (cPNA) 2 years of preterm infants previously enrolled in an RCT and treated with IN-REC-SUR-E or IN-SUR-E in 35 tertiary neonatal intensive care units.

DESIGN, SETTING, AND PARTICIPANTS

This was a follow-up study of infants recruited into the primary RCT from 2015 to 2018 at 35 tertiary neonatal intensive care units (NICUs) in Italy. Follow-up examinations included neurodevelopmental, growth, and respiratory outcomes of these children at cPNA 2 years. Participants included spontaneously breathing extremely preterm neonates (24 0/7 to 27 6/7 weeks' gestation) reaching failure criteria for continuous positive airway pressure within the first 24 hours of life. Data were analyzed from April 2023 to January 2024.

INTERVENTION

Infants were randomly assigned (1:1) to IN-REC-SUR-E or IN-SUR-E and then followed up.

MAIN OUTCOMES AND MEASURES

The primary outcome was the occurrence of death after discharge or major disability at cPNA 2 years. Secondary outcomes were neurodevelopmental outcomes (major disability, cerebral palsy, cognitive impairment, visual deficit, or auditory deficit), anthropometric measurements (weight, length, and head circumference), and recurrent respiratory infections and hospitalizations because of respiratory causes at 2y cPNA.

RESULTS

A total of 137 extremely preterm infants (median [IQR] gestational age, 26.5 [25.3-27.5] weeks and 75 [54.7%] female), initially enrolled in the original RCT, were followed up at cPNA 2 years, including 64 infants in the IN-SUR-E group and 73 infants in the IN-REC-SUR-E group. There were no significant differences in the occurrence of death after discharge or major disability at cPNA 2 years (IN-SUR-E: 13 children [20.3%] vs IN-REC-SUR-E: 10 children [13.7%]; P = .36). There were no significant differences in incidence of disability, cerebral palsy, or cognitive impairment in the IN-REC-SUR-E group compared with the IN-SUR-E group. There were no significant differences in anthropometric measurements (weight, length, and head circumference) between groups. There were no significant differences in the incidence of recurrent respiratory infections or in hospitalizations because of respiratory causes between groups.

CONCLUSIONS AND RELEVANCE

In this RCT of lung recruitment before surfactant vs standard care there were no significant differences between the 2 groups in death, neurodevelopmental outcomes, anthropometric measurements, or recurrent respiratory infections at the 2-year follow-up. These findings can aid clinicians in decision-making for the best strategy to administer surfactant, considering long-term outcomes.

Mitochondrial DNA mutations in extremely preterm infants with bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a serious chronic lung disease affecting extremely preterm infants. While mitochondrial dysfunction has been investigated in various medical conditions, limited research has explored mitochondrial DNA (mtDNA) gene mutations, specifically in BPD. This study aimed to evaluate mitochondrial mtDNA gene mutations in extremely preterm infants with BPD. In this prospective observational study, we enrolled a cohort of extremely preterm infants diagnosed with BPD. Clinical data were collected to provide comprehensive patient profiles. Peripheral blood mononuclear cells were isolated from whole-blood samples obtained within a defined timeframe. Subsequently, mtDNA extraction and sequencing using next-generation sequencing technology were performed to identify mtDNA gene mutations. Among the cohort of ten extremely preterm infants with BPD, mtDNA sequencing revealed the presence of mutations in seven patients, resulting in a total of twenty-one point mutations. Notably, many of these mutations were identified in loci associated with critical components of the respiratory chain complexes, vital for proper mitochondrial function and cellular energy production. This pilot study provides evidence of mtDNA point mutations in a subset of extremely preterm infants with BPD. These findings suggest a potential association between mitochondrial dysfunction and the pathogenesis of BPD. Further extensive investigations are warranted to unravel the mechanisms underlying mtDNA mutations in BPD.

Inpatient education reduces length of outpatient oxygen therapy in bronchopulmonary dysplasia: A quality improvement project

BACKGROUND

Patients discharged on home oxygen therapy (HOT) for bronchopulmonary dysplasia (BPD) often receive months of this therapy. A previous trial comparing two methods of HOT weaning showed that increased parent involvement in HOT weaning decreased HOT duration. Our outpatient team uses a standard protocol for outpatient HOT weaning, starting at the first clinic visit 4-6 weeks after discharge.

AIM

To shorten HOT duration by teaching parents the outpatient HOT weaning process before neonatal intensive care unit (NICU) discharge.

METHODS

We launched a quality improvement program in April 2021 for preterm infants with BPD without significant comorbidities who were stable on ≤0.5 L nasal cannula. Eligible infants started the outpatient HOT weaning protocol while inpatient, with education for parents and nurses. The outcome measure was the duration of HOT after discharge. Process measures focused on protocol adherence. Balancing measures included NICU length of stay and appropriateness of parent-directed HOT weaning.

RESULTS

During the study period, there were a total of 133 eligible patients discharged on home oxygen, with 75 in the baseline group and 58 in the intervention group. Forty-five (78%) participated in the HOT weaning protocol while inpatient. HOT was reduced from an average of 27 to 12 weeks after May 2021. We observed no change in NICU length of stay or inappropriate HOT weaning.

CONCLUSION

Early introduction of HOT weaning with a focus on caregiver education is associated with a decreased duration of HOT.

Effects of bradycardia, hypoxemia and early intubation on bronchopulmonary dysplasia in very preterm infants: An observational study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is the most common pulmonary complication in preterm infants.

OBJECTIVES

The study aimed to explore the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants.

METHODS

This is a prospective observational cohort study. Preterm infants with a mean gestational age of 28.67 weeks were recruited from two level III neonatal intensive care units (NICUs) in Taiwan. Continuous electrocardiography was used to monitor heart rates and oxygen saturation (SpO2). Infants were monitored for heart rates of <100 beats per minute and SpO2 levels of <90 % lasting for 30 s. Generalized estimating equations were used to analyze the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants. Model fit was visually assessed using receiver operating characteristic curve analysis.

RESULTS

Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among the preterm infants (N = 39) during NICU stay; the odds ratios for bradycardia, hypoxemia, and early intubation for BPD versus non-BPD were 1.058, 1.013, and 29.631, respectively (all p < 0.05). A model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development (area under the curve = 0.919).

CONCLUSIONS

Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among very preterm infants during NICU stay. The model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development.

Improving early diagnosis of bronchopulmonary dysplasia

INTRODUCTION

Bronchopulmonary disease (BPD) is associated with long-term neurodevelopmental and cardiorespiratory complications, often requiring significant use of resources. To reduce this healthcare burden, it is essential that those at high risk of BPD are identified early so that strategies are introduced to prevent disease progression. Our aim was to discuss potential methods for improving early diagnosis in the first week after birth.

AREAS COVERED

A narrative review was undertaken. The search strategy involved searching PubMed, Embase and Cochrane databases from 1967 to 2024. The results of potential biomarkers and imaging modes are discussed. Furthermore, the value of scoring systems is explored.

EXPERT OPINION

BPD occurs as a result of disruption to pulmonary vascular and alveolar development, thus abnormal levels of factors regulating those processes are promising avenues to explore with regard to early detection of high-risk infants. Data from twin studies suggests genetic factors can be attributed to 82% of the observed difference in moderate to severe BPD, but large genome-wide studies have yielded conflicting results. Comparative studies are required to determine which biomarker or imaging mode may most accurately diagnose early BPD development. Models which include the most predictive factors should be evaluated going forward.

Incidence and Predictors of Bronchopulmonary Dysplasia Development and Severity Among Preterm Infants Born at 32 Weeks of Gestation or Less

Background As the most common chronic lung disease (CLD) related to premature birth, bronchopulmonary dysplasia (BPD) is associated with long-term lung disease along with cardiovascular and neurodevelopmental disorders. However, data on the incidence and predictors of BPD in Qatar are lacking. Objectives In this study, we aimed to determine the incidence of BPD among infants born at ≤ 32 weeks gestational age (GA) at our neonatal unit, and identify risk factors for the development of BPD and moderate-severe BPD. Methods This was a retrospective observational cohort study conducted at a single site: a level-III neonatal intensive care unit (NICU) in Qatar. We included 1539 neonates born at ≤ 32 weeks of gestation with birth weights of ≤ 1500 grams who were admitted to the NICU between 2017 and 2020. Univariate and multivariate logistic regression analyses were performed to identify potential factors and predictors and their possible associations with the development of BPD and moderate-severe BPD. We also applied BPD classifications to determine the variability in the incidence of BPD in our cohort according to various definitions (2001 National Institute of Child Health and Human Development (NICHD) Diagnostic Criteria, 2016 Revisions of NICHD Criteria, and 2019 Neonatal Research Network Jensen Grading). Results A total of 451 infants (29.3%) had BPD (BPD group) while 1088 (70.7%) did not (non-BPD group), and the overall incidence of BPD was 29.3%. The most relevant risk factors associated with a higher risk of developing BPD identified in the multivariate logistic regression analysis were appropriate weight for gestational age (adjusted OR (aOR) 3.67, 95%CI 2.02-6.67, P < 0.001), presence of patent ductus arteriosus (PDA) (aOR 2.61, 95%CI 1.86-3.66, P < 0.001), late-onset sepsis (aOR 2.16; 95%CI 1.29-3.62; P = 0.003), and use of invasive ventilation (aOR 1.90; 95%CI 1.35-2.69; P < 0.001). The most relevant independent risk factors associated with a higher risk for developing moderate-severe BDP were postnatal steroids (aOR 7.12, 95%CI 3.77-13.44, P < 0.001), use of inhaled nitric oxide (aOR 3.65, 95%CI 1.48-9.01, P = 0.005), use of invasive ventilation (aOR 2.13, 95%CI 1.13-4.00, P = 0.019), late-onset sepsis (aOR 2.07, 95%CI 1.10-3.91, P = 0.025), and male sex (aOR 2.04, 95%CI 1.24-3.36, P = 0.005). The difference in the distribution of BPD severity across the three different definitions of NICHD was significant (P < 0.001). Conclusion The results of this study showed that the incidence of BPD remained high in infants born at ≤ 32 weeks of gestational age and birth weight <1500 g with appropriate weight for gestational age. The presence of PDA at birth or first echocardiography, late-onset sepsis, and use of invasive ventilation were significant risk factors for the incidence of BPD. The identification of risk factors will contribute to the implementation of lung-protective strategies for at-risk infants who may benefit from potential preventive therapy.

A Review of the Use of Extracellular Vesicles in the Treatment of Neonatal Diseases: Current State and Problems with Translation to the Clinic

Neonatal disorders, particularly those resulting from prematurity, pose a major challenge in health care and have a significant impact on infant mortality and long-term child health. The limitations of current therapeutic strategies emphasize the need for innovative treatments. New cell-free technologies utilizing extracellular vesicles (EVs) offer a compelling opportunity for neonatal therapy by harnessing the inherent regenerative capabilities of EVs. These nanoscale particles, secreted by a variety of organisms including animals, bacteria, fungi and plants, contain a repertoire of bioactive molecules with therapeutic potential. This review aims to provide a comprehensive assessment of the therapeutic effects of EVs and mechanistic insights into EVs from stem cells, biological fluids and non-animal sources, with a focus on common neonatal conditions such as hypoxic-ischemic encephalopathy, respiratory distress syndrome, bronchopulmonary dysplasia and necrotizing enterocolitis. This review summarizes evidence for the therapeutic potential of EVs, analyzes evidence of their mechanisms of action and discusses the challenges associated with the implementation of EV-based therapies in neonatal clinical practice.

Prediction of bronchopulmonary dysplasia in very preterm infants: competitive risk model nomogram

Objective

To develop predictive clinical models of bronchopulmonary dysplasia (BPD) through competing risk analysis.

Methods

Retrospective observational cohort study, including preterm newborns ≤32 weeks gestational age, conducted between January 1, 2013 and September 30, 2022 in a third-level Neonatal Intensive Care Unit in Spain. A prediction study was carried out using competing risk models, where the event of interest was BPD and the competing event was death. A multivariate competing risk model was developed separately for each postnatal day (days 1, 3, 7 and 14). Nomograms to predict BPD risk were developed from the coefficients of the final models and internally validated.

Results

A total of 306 patients were included in the study, of which 73 (23.9%) developed BPD and 29 (9.5%) died. On day 1, the model with the greatest predictive capacity was that including birth weight, days since rupture of membranes, and surfactant requirement (area under the receiver operating characteristic (ROC) curve (AUC), 0.896; 95% CI, 0.792-0.999). On day 3, the final predictive model was based on the variables birth weight, surfactant requirement, and Fraction of Inspired Oxygen (FiO2) (AUC, 0.891; 95% CI, 0.792-0.989).

Conclusions

Competing risk analysis allowed accurate prediction of BPD, avoiding the potential bias resulting from the exclusion of deceased newborns or the use of combined outcomes. The resulting models are based on clinical variables measured at bedside during the first 3 days of life, can be easily implemented in clinical practice, and can enable earlier identification of patients at high risk of BPD.

Comprehensive Analysis of Risk Factors for Bronchopulmonary Dysplasia in Preterm Infants in Taiwan: A Four-Year Study

Bronchopulmonary dysplasia (BPD) is a major respiratory condition mainly affecting premature infants. Although its occurrence is global, risk factors may differ regionally. This study, involving 3111 infants with birth weight ≤ 1500 gm or gestational age (GA) < 30 weeks, aimed to identify risk factors for BPD and BPD/mortality in Taiwan using data from the Taiwan Neonatal Network. The BPD criteria were based on the National Institute of Child Health and Human Development standards. Average GA was 27.5 weeks, with 23.7% classified as small for GA (SGA). Multivariate analysis highlighted low GA, low birth weight, and other perinatal factors as significant risk indicators for BPD. For moderate-to-severe BPD, additional risk factors included male gender and SGA, endotracheal intubation (ETT) or cardiopulmonary cerebral resuscitation (CPCR) in initial resuscitation. In the moderate-to-severe BPD/death group, SGA and ETT or CPCR in initial resuscitation remained the only additional risk factors. The study pinpoints male gender, SGA and ETT or CPCR as key risk factors for moderate-to-severe BPD/death in low-birth-weight infants in Taiwan, offering a basis for focused interventions and further research.

Risk factors for bronchopulmonary dysplasia infants with respiratory score greater than four: a multi-center, prospective, longitudinal cohort study in China

Bronchopulmonary dysplasia (BPD) is the most common complication of prematurity involving both pre- and post-natal factors. A large, prospective, longitudinal cohort study was conducted to determine whether inflammation-related factors are associated with an increased risk of BPD in preterm infants who were born at a gestational age < 32 weeks, < 72 h after birth and respiratory score > 4. The study included infants from 25 participating hospitals in China between March 1, 2020 and March 31, 2022. The primary outcomes were BPD and severity of BPD at 36 weeks post-menstrual age. A total of 1362 preterm infants were enrolled in the study. After exclusion criteria, the remaining 1088 infants were included in this analysis, of whom, 588 (54.0%) infants were in the BPD group and 500 (46.0%) were in the non-BPD group. In the BPD III model, the following six factors were identified: birth weight (OR 0.175, 95% CI 0.060-0.512; p = 0.001), surfactant treatment (OR 8.052, 95% CI 2.658-24.399; p < 0.001), mean airway pressure (MAP) ≥ 12 cm H2O (OR 3.338, 95% CI 1.656-6.728; p = 0.001), late-onset sepsis (LOS) (OR 2.911, 95% CI 1.514-5.599; p = 0.001), ventilator-associated pneumonia (VAP) (OR 18.236, 95% CI 4.700-70.756; p < 0.001) and necrotizing enterocolitis (NEC) (OR 2.725, 95% CI 1.182-6.281; p = 0.019). Premature infants remained at high risk of BPD and with regional variation. We found that post-natal inflammation-related risk factors were associated with an increased risk of severe BPD, including LOS, VAP, NEC, MAP ≥ 12 cm H2O and use of surfactant.

Complex roles of TGF-β signaling pathways in lung development and bronchopulmonary dysplasia

As survival of extremely preterm infants continues to improve, there is also an associated increase in bronchopulmonary dysplasia (BPD), one of the most significant complications of preterm birth. BPD development is multifactorial resulting from exposure to multiple antenatal and postnatal stressors. BPD has both short-term health implications and long-term sequelae including increased respiratory, cardiovascular, and neurological morbidity. Transforming growth factor β (TGF-β) is an important signaling pathway in lung development, organ injury, and fibrosis and is implicated in the development of BPD. This review provides a detailed account on the role of TGF-β in antenatal and postnatal lung development, the effect of known risk factors for BPD on the TGF-β signaling pathway, and how medications currently in use or under development, for the prevention or treatment of BPD, affect TGF-β signaling.

Phase I trial of human umbilical cord-derived mesenchymal stem cells for treatment of severe bronchopulmonary dysplasia

Severe bronchopulmonary dysplasia (BPD) is a chronic lung disorder that primarily affects premature babies with extremely low birth weight and involves in multiple organ system; no effective pharmacotherapy for this disease exists, and mortality remains high. Based on the evidence from previous preclinical studies and phase I clinical trials, this study aims to test the safety of intravenous application of a single dose of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in patients with severe BPD. The Mesenchymal Stem cells for Bronchopulmonary Dysplasia Treatment (MSBDT) trial is a single center, open-label, dose-escalation phase I clinical trial. Severe BPD patients were enrolled in Children Hospital of Chongqing Medical University, Chongqing, China. The first six patients were treated with low-dose hUC-MSCs (1 × 106 cells/kg) and the next seven patients were treated with high-dose hUC-MSCs (5 × 106 cells/kg). This study is registered with ClinicalTrials.gov, number NCT03558334. No prespecified infusion-associated adverse events, immediate complication, respiratory or cardiovascular compromise were observed during infusion and 24 h after infusion. No significant changes in safety laboratory values were observed. One death event occurred in the low-dose group on study day 10, and one death event occurred in the high-dose group on study day 24, while, after review in detail, the two cases are not believed to be infusion-associated events. In conclusion, intravenous application of a single dose of hUC-MSCs was tolerated in thirteen patients with severe BPD.

Artificial intelligence in bronchopulmonary dysplasia- current research and unexplored frontiers

Provide an overview of bronchopulmonary dysplasia, its definitions, and their shortcomings. Explore the areas where machine learning may be used to further our understanding of bronchopulmonary dysplasia.

Development of a peripheral blood transcriptomic gene signature to predict bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most common lung disease of extreme prematurity, yet mechanisms that associate with or identify neonates with increased susceptibility for BPD are largely unknown. Combining artificial intelligence with gene expression data is a novel approach that may assist in better understanding mechanisms underpinning chronic lung disease and in stratifying patients at greater risk for BPD. The objective of this study is to develop an early peripheral blood transcriptomic signature that can predict preterm neonates at risk for developing BPD. Secondary analysis of whole blood microarray data from 97 very low birth weight neonates on day of life 5 was performed. BPD was defined as positive pressure ventilation or oxygen requirement at 28 days of age. Participants were randomly assigned to a training (70%) and testing cohort (30%). Four gene-centric machine learning models were built, and their discriminatory abilities were compared with gestational age or birth weight. This study adheres to the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) statement. Neonates with BPD (n = 62 subjects) exhibited a lower median gestational age (26.0 wk vs. 30.0 wk, P < 0.01) and birth weight (800 g vs. 1,280 g, P < 0.01) compared with non-BPD neonates. From an initial pool (33,252 genes/patient), 4,523 genes exhibited a false discovery rate (FDR) <1%. The area under the receiver operating characteristic curve (AUC) for predicting BPD utilizing gestational age or birth weight was 87.8% and 87.2%, respectively. The machine learning models, using a combination of five genes, revealed AUCs ranging between 85.8% and 96.1%. Pathways integral to T cell development and differentiation were associated with BPD. A derived five-gene whole blood signature can accurately predict BPD in the first week of life.

[Influencing factors for the development and severity of bronchopulmonary dysplasia in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g]

OBJECTIVES

To study the influencing factors for the development and severity of bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g.

METHODS

A retrospective analysis was performed on the medical data of preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g who were admitted to Women and Children's Hospital Affiliated to Xiamen University from January 1, 2017 to December 31, 2021. According to oxygen dependence on day 28 after birth, they were divided into two groups: BPD (n=218) and non-BPD (n=142). According to disease severity based on oxygen concentration required at the corrected age of 36 weeks or at discharge, the infants with BPD were divided into two groups: mild BPD (n=154) and moderate/severe BPD (n=64). Indices such as perinatal data and nutritional status were compared between groups. The multivariate logistic regression analysis was used to determine the influencing factors for BPD and its severity.

RESULTS

The incidence rate and severity of BPD increased with the reduction in gestational age and birth weight (P<0.05). The multivariate logistic regression analysis showed that a long duration of invasive mechanical ventilation (OR=1.320, P<0.05), hemodynamically significant patent ductus arteriosus (OR=2.032, P<0.05), and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.041, P<0.05) were risk factors for BPD, while an older gestational age was a protective factor against BPD (OR=0.535, P<0.05). Early-onset sepsis (OR=2.524, P<0.05) and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.029, P<0.05) were risk factors for moderate/severe BPD, while a high mean weight growth velocity was a protective factor against moderate/severe BPD (OR=0.906, P<0.05).

CONCLUSIONS

The incidence rate and severity of BPD in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g can be reduced by shortening the duration of invasive mechanical ventilation, giving early treatment of early-onset sepsis and hemodynamically significant patent ductus arteriosus, adopting active enteral nutritional strategies, and increasing mean weight growth velocity.

Diagnosis and management of pulmonary hypertension in infants with bronchopulmonary dysplasia: a guide for paediatric respiratory specialists

Pulmonary hypertension (PH) can develop in babies with bronchopulmonary dysplasia (BPD). PH is common in those with severe BPD and is associated with a high mortality rate. However, in babies surviving beyond 6 months, resolution of PH is likely. There is currently no standardised screening protocol for PH in BPD patients. Diagnosis in this group relies heavily on transthoracic echocardiography. Management of BPD-PH should be led by a multidisciplinary team and focus on optimal medical management of the BPD and associated conditions that may contribute to PH. PH-targeted pharmacotherapies have been used in BPD-PH. To date, these have not been investigated in clinical trials and evidence of their efficacy and safety is absent.

Educational aims

To identify those BPD patients most at risk of developing PH.To be aware of detection, multidisciplinary management, pharmacological treatment and monitoring strategies for BPD-PH patients.To understand the potential clinical course for patients with BPD-PH and that evidence on efficacy and safety of PH-targeted pharmacotherapy in BPD-PH is limited.

[Risk factors for moderate/severe bronchopulmonary dysplasia in preterm infants with a gestational age of <32 weeks: a multicenter retrospective analysis]

OBJECTIVES

To investigate the risk factors for moderate/severe bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age of <32 weeks.

METHODS

A retrospective analysis was performed on the medical data of preterm infants with a gestational age of <32 weeks and a length of hospital stay of ≥28 days who were admitted to the neonatal intensive care unit (NICU) of 17 institutions of Jiangsu Neonatal Perinatal Cooperation Network from January 1, 2019 to December 31, 2020 and were diagnosed with BPD. The preterm infants were grouped according to gestational age and severity of BPD. A multivariate logistic regression analysis was used to investigate the risk factors for moderate/severe BPD in various gestational age groups.

RESULTS

During the two-year period, a total of 2 603 preterm infants with a gestational age of <32 weeks were admitted to the NICU of the 17 institutions, among whom 961 were diagnosed with BPD, and the incidence rates of BPD and moderate/severe BPD were 36.92% (961/2 603) and 8.64% (225/2 603), respectively. The incidence rate of moderate/severe BPD was 56.5% (26/46) in preterm infants with a gestational age of 24+0-25+6 weeks, 31.0% (66/213) in those with a gestational age of 26+0-27+6 weeks, 16.9% (75/445) in those with a gestational age of 28+0-29+6 weeks, and 22.6% (58/257) in those with a gestational age of 30+0-31+6 weeks. The multivariate logistic regression analysis showed that there were different risk factors for moderate/severe BPD in preterm infants with different gestational ages: patent ductus arteriosus requiring treatment as risk factors in preterm infants with a gestational age of 24+0-25+6 weeks; premature rupture of membranes ≥18 hours, positive pressure ventilation for resuscitation, clinical sepsis, and duration of mechanical ventilation ≥14 days as risk factors in preterm infants with a gestational age of 26+0-27+6 weeks; duration of mechanical ventilation ≥14 days, neonatal pneumonia, and patent ductus arteriosus requiring treatment as risk factors in preterm infants with a gestational age of 28+0-29+6 weeks; positive pressure ventilation for resuscitation, neonatal pneumonia, and anemia of prematurity as risk factors in preterm infants with a gestational age of 30+0-31+6 weeks (P<0.05).

CONCLUSIONS

The development of moderate/severe BPD is multifactorial in preterm infants with a gestational age of <32 weeks, and there are different risk factors in different gestational age groups. Targeted preventive measures for preterm infants of different gestational ages may be useful to reduce the severity of BPD.

Nutrition of Infants with Bronchopulmonary Dysplasia before and after Discharge from the Neonatal Intensive Care Unit

Bronchopulmonary dysplasia (BPD) represents a severe sequela in neonates born very prematurely. The provision of adequate nutritional support in this high-risk population is challenging. The development of the lungs and physical growth are closely linked together in infants with BPD. Growth deficiency has been associated with pulmonary dysfunction, whereas improvement in respiratory status results in growth acceleration. Currently, there is not enough data regarding optimal nutritional strategies in this population. Nutrition in these infants should provide sufficient calories and nutrients to establish growth, avoid growth retardation and assist alveolarization of the lungs. Meticulous follow-up is mandatory during and after discharge from the Neonatal Intensive care Unit (NICU) to minimize growth retardation and improve lung function. Despite the significant literature supporting the contribution of growth and nutrition in the avoidance of BPD, there is limited research regarding interventions and management of infants with established BPD. Our aim was to review clinical strategies applied in everyday clinical practice and identify debates on the nutritional approach of newborns with BPD. Well-organized interventions and clinical trials regarding the somatic development and nutrition of infants with BPD are warranted.

Caffeine and bronchopulmonary dysplasia: Clinical benefits and the mechanisms involved

Bronchopulmonary dysplasia (BPD) is a chronic respiratory disease that occurs during the neonatal period and is commonly associated with prematurity. This condition results in a severe economic burden on society and the families involved. Caffeine is used not only for the treatment of apnea in prematurity, but also for the prevention of BPD. There are multiple clinical benefits of caffeine treatment, including improved extubation success, a reduced duration of mechanical ventilation, improved lung function, and a reduction of patent ductus arteriosus requiring treatment. These clinical benefits of caffeine for the treatment of BPD are supported by both clinical trials and evidence from animal models. However, the mechanism by which caffeine protects against BPD remains unclear. Here, we review the clinical value of caffeine in the prevention of BPD and its potential mechanisms of action, including anti-inflammatory, antioxidant, antifibrotic, and antiapoptotic properties, the regulation of angiogenesis, and diuretic effects. Our aim is to provide a new theoretical basis for the clinical treatment of BPD.

Increased Risk for Respiratory Complications in Male Extremely Preterm Infants: A Propensity Score Matching Study

BACKGROUND

Many factors can affect the clinical outcome of extremely premature infants (EPIs), but the effect of sex is paradoxical. This study used propensity score matching to adjust baseline information to reassess the clinical outcome of EPIs based on sex.

METHODS

A retrospective analysis was performed on EPIs admitted in the Department of Neonatology of the Third Affiliated Hospital of Guangzhou Medical University from 2011 to 2020. A propensity score matching (PSM) analysis was used to adjust the confounding factors including gestational age, birth weight, 1-minute Apgar score ≤ 3, withholding or withdrawing life-sustaining treatment(WWLST), mechanical ventilation, duration of mechanical ventilation, the mother with advanced age (≥35 years old), complete-course antenatal steroid therapy and hypertensive disorders of pregnancy. The survival rate at discharge and the incidence of major complications were evaluated between the male and female groups.

RESULTS

A total of 439 EPIs were included, and 240 (54.7%) infants were males. After matching the nine confounding factors, 148 pairs of infants were finally enrolled. There was no significant difference in the survival rate at discharge, as well as the mortality of activating treatment or WWLST between the two groups (all P>0.05). However, the incidence of respiratory distress syndrome, bronchopulmonary dysplasia (BPD), and moderate to severe BPD in the male group was significantly increased (all P<0.01), especially at birth weight between 750 and 999 grams.

CONCLUSIONS

The male EPIs have a higher risk of respiratory complications than females, particularly at 750 to 999 grams of birth weight.