Congenital Diaphragmatic Hernia: Pulmonary Hypertension and Pulmonary Vascular Disease.

This review provides a comprehensive summary of the current understanding of pulmonary hypertension (PH) in congenital diaphragmatic hernia, outlining the underlying pathophysiologic mechanisms, methods for assessing PH severity, optimal management strategies, and prognostic implications.

The effect of fertility treatment and socioeconomic status on neonatal and post-neonatal mortality in the United States.

OBJECTIVE: To determine the association between fertility treatment, socioeconomic status (SES), and neonatal and post-neonatal mortality. STUDY DESIGN: Retrospective cohort study of all births (19,350,344) and infant deaths from 2014-2018 in the United States. The exposure was mode of conception-spontaneous vs fertility treatment. The outcome was neonatal (<28d), and post-neonatal (28d-1y) mortality. Multivariable logistic models were stratified by SES. RESULT: The fertility treatment group had statistically significantly higher odds of neonatal mortality (high SES OR 1.59; CI [1.5, 1.68], low SES OR 2.11; CI [1.79, 2.48]) and lower odds of post-neonatal mortality (high SES OR 0.87, CI [0.76, 0.996], low SES OR 0.6, CI [0.38, 0.95]). SES significantly modified the effect of ART/NIFT on neonatal and post-neonatal mortality. CONCLUSIONS: Fertility treatment is associated with higher neonatal and lower post-neonatal mortality and SES modifies this effect. Socioeconomic policies and support for vulnerable families may help reduce rates of infant mortality.

Prostaglandin-E1 infusion in persistent pulmonary hypertension of the newborn.

BACKGROUND: Neonates with persistent pulmonary hypertension of the newborn (PPHN) can present with hypoxia and right ventricular dysfunction with resultant inadequate oxygen delivery and end-organ damage. This study describes the use of prostaglandin-E1 (PGE) for ductal patency to preserve right ventricular systolic function and limit afterload in newborns with PPHN. METHODS: This is a retrospective cohort study that follows the hemodynamics, markers of end-organ perfusion, length of therapeutics, and echocardiographic variables of 57 newborns who used prostglandin-E1 in the setting of PPHN. RESULTS: Tachycardia, lactic acidosis, and supplemental oxygen use improved following PGE initiation. Fractional area change (FAC), to assess right ventricular systolic function, and pulmonary arterial acceleration time indexed to right ventricular ejection time (PAAT/RVET), to assess right ventricular afterload, also improved over three time points relative to PGE use (before, during, and after). CONCLUSIONS: Overall, we described the safety and utility of PGE in newborns with severe PPHN for stabilization while allowing natural disease progression.

Fertility treatment increases the risk of preterm birth independent of multiple gestations.

Objective: To investigate the complex interplay between fertility treatment, multiple gestations, and prematurity. Design: Retrospective cohort study linking the national Center for Disease Control and Prevention infant birth and death data from 2014 to 2018. Setting: National database from Center of Disease Control and Prevention. Patients: In total, 19,454,155 live-born infants with gestational ages 22-44 weeks, 114,645 infants born using non IVF fertility treatment (NIFT), and 179,960 via assisted reproductive technology (ART). Intervention: Noninvasive fertility treatment or ART vs. spontaneously conceived pregnancies. Main Outcome Measures: The main outcome assessed was prematurity. Formal mediation analysis was conducted to calculate the percentage mediated by multiple gestations. Results: Newborns born using NIFT or ART compared with those with no fertility treatment had a higher incidence of multiple gestation (no fertility treatment = 3.0%; NIFT = 24.7%; ART = 32.7%; P<.001) and prematurity (no fertility treatment = 11.2%; NIFT = 23.4%; ART = 28.4%; P<.001). Mediation analysis demonstrates that 76.8% (95% confidence interval [CI], 75.2%-78.1%) of the effect of NIFT on prematurity was mediated through multiple gestations. Similarly, 71.2% (95% CI, 70.8%-72.7%) of the effect of ART on prematurity is mediated through multiple gestation. However, the direct effect of NIFT on prematurity is 20.4% (95% CI, 19.0%-22.0%). The direct effect of ART was 24.7% (95% CI, 23.7%-25.6%). Conclusion: A significant proportion of prematurity associated with fertility treatment is mediated by the treatment itself, independent of multiple gestations.

Safety and tolerability of continuous inhaled iloprost in critically ill pediatric pulmonary hypertension patients: A retrospective case series.

Inhaled iloprost (iILO) has shown efficacy in treating patients with hypoxic lung disease and pulmonary hypertension, inducing selective pulmonary vasodilation and improvement in oxygenation. However, its short elimination half-life of 20-30 min necessitates frequent intermittent dosing (6-9 times per day). Thus, the administration of iILO via continuous nebulization represents an appealing method of drug delivery in the hospital setting. The objectives are: (1) describe our continuous iILO delivery methodology and safety profile in mechanically ventilated pediatric pulmonary hypertension patients; and (2) characterize the initial response of iILO in these pediatric patients currently receiving iNO. Continuous iILO was delivered and well tolerated (median 6 days; range 1-94) via tracheostomy or endotracheal tube using the Aerogen® mesh nebulizer system coupled with a Medfusion® 400 syringe pump. No adverse events or delivery malfunctions were reported. Initiation of iILO resulted in an increase in oxygen saturation from 81.4 ± 8.6 to 90.8 ± 4.1%, p < 0.05. Interestingly, prior iNO therapy for >1 day resulted in a higher response rate to iILO (as defined as a ≥ 4% increase in saturations) compared to those receiving iNO <1 day (85% vs. 50%, p = 0.06). When the use of iILO is considered, continuous delivery represents a safe, less laborious alternative and concurrent treatment with iNO should not be considered a contraindication. However, given the retrospective design and small sample size, this study does not allow the evaluation of the efficacy of continuous iILO on outcomes beyond the initial response. Thus, a prospective study designed to evaluate the efficacy of continuous iILO is necessary.

Sociodemographic factors associated with tracheostomy and mortality in bronchopulmonary dysplasia.

OBJECTIVES: We sought to investigate how race, ethnicity, and socioeconomic status relate to tracheostomy insertion and post-tracheostomy mortality among infants with bronchopulmonary dysplasia (BPD). METHODS: The Vizient Clinical Database/Resource Manager was queried to identify infants born ≤32 weeks with BPD admitted to US hospitals from January 2012 to December 2020. Markers of socioeconomic status were linked to patient records from the Agency for Healthcare Research and Quality's Social Determinants of Health Database. Regression models were used to assess trends in annual tracheostomy insertion rate and odds of tracheostomy insertion and post-tracheostomy mortality, adjusting for sociodemographic and clinical factors. RESULTS: There were 40,021 ex-premature infants included in the study, 1614 (4.0%) of whom received a tracheostomy. Tracheostomy insertion increased from 2012 to 2017 (3.1%-4.1%), but decreased from 2018 to 2020 (3.3%-1.6%). Non-Hispanic Black infants demonstrated a 25% higher odds (aOR 1.25, 1.09-1.43) and Hispanic infants demonstrated a 20% lower odds (aOR 0.80, 0.65-0.96) of tracheostomy insertion compared with non-Hispanic White infants. Patients receiving public insurance had increased odds of tracheostomy insertion (aOR 1.15, 1.03-1.30), but there was no relation between other metrics of socioeconomic status and tracheostomy insertion within our cohort. In-hospital mortality among the tracheostomy-dependent was 14.1% and was not associated with sociodemographic factors. CONCLUSIONS: Disparities in tracheostomy insertion are not accounted for by differences in socioeconomic status or the presence of additional neonatal morbidities. Post-tracheostomy mortality does not demonstrate the same relationships. Further investigation is needed to explore the source and potential mitigators of the identified disparities.

Expected small left heart size in the presence of congenital diaphragmatic hernia: Fetal values and Z-scores for infants confirmed to have no heart disease postnatally.

Objectives: In fetuses with left-sided congenital diaphragmatic hernia (CDH), left heart structures may appear small, but usually normalize after birth in the absence of structural cardiac anomalies. To decrease the possibility of an erroneous diagnosis of structural heart disease, we identify normal values for left heart structures in the presence of left CDH and secondarily investigate the relationship of left heart size and survival to neonatal hospital discharge. Methods: Left heart structures [mitral valve (MV) and aortic valve (AoV) annulus diameter, left ventricle (LV) length and width] were measured by fetal echocardiogram in fetuses with left CDH and no congenital heart disease. We generated linear regression models to establish the relationship of gestational age for each left heart structure using data from fetuses who survived after birth. We calculated z-scores (normalized to gestational age), and assessed the relationship of survival to the size of each structure. Results: One hundred forty-two fetuses underwent fetal echocardiogram (median 25 weeks' gestation, IQR 23, 27 weeks). Left heart structures were deemed small when using published normative data from unaffected fetuses (z-scores: MV -1.09 ± 1.35, AoV -2.12 ± 1.16, LV length -1.36 ± 1.24, LV width -4.79 ± 0.79). CDH-specific models derived from log-transformed values yielded left-shifted distributions, reflecting the small structures (mean z-score lower by: MV 0.99 ± 0.30, AoV 2.04 ± 0.38, LV length 1.30 ± 0.36, and LV width 4.69 ± 0.28; p < 0.0001 for all comparisons). Non-survivors had worse z-scores than survivors for all measurements, but this did not reach statistical significance. Conclusions: Log-transformed linear models generated new normative data for fetal left heart structures in left CDH, which may be used to allay antenatal concerns regarding structural left heart anomalies. There were no significant differences in z-scores between survivors and non-survivors, suggesting that in the absence of true structural disease, cardiac evaluation is not predictive in isolation and that causes of mortality are likely multifactorial in this population.

Persistence of persistent pulmonary hypertension of the newborn: A case of de novo TBX4 variant.

We present a case of a late preterm infant placed on extracorporeal life support in the first day of life for persistent pulmonary hypertension of the newborn. Developmental arrest, pulmonary vascular hypertensive changes, and pulmonary interstitial glycogenosis were present on lung biopsy at 7 weeks of age. Pulmonary hypertension has persisted through childhood. Genetic testing at 8 years identified a novel mutation in TBX4.

Pulmonary artery acceleration time in young children is determined by heart rate and transpulmonary gradient but not by pulmonary blood flow: A simultaneous echocardiography-cardiac catheterization study.

INTRODUCTION: Pulmonary artery acceleration time (PAAT) is considered useful for the non-invasive evaluation of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR). PAAT is dependent on PAP, PVR, pulmonary artery compliance, stroke volume, and heart rate. Its relative dependency on these determinants may differ between young and older children, raising uncertainty regarding its utility in young children. We aim to identify the primary determinants of the PAAT in children less than 36 months undergoing cardiac catheterization and its utility for the diagnosis of elevated PVR. METHODS: We prospectively studied 42 children undergoing cardiac catheterization and simultaneous echocardiography. We determined the correlations of PAAT to the above-mentioned determinants and evaluated receiver operator characteristic (ROC) curves for diagnosis of PVR indexed to body surface area (PVRi) ≥3 Wu*m2 . RESULTS: Median age was 11.5 (IQR 5.2, 21.2) months. Moderate correlations were found between PAAT and mean PAP (R = -.66, p < .001), PVRi (R = -.54, p = .004), pulmonary artery compliance (R = .65, p < .001), transpulmonary gradient (R = -.67, p < .001), stroke volume (R = .61, p = .002), and heart rate (R = -.63, p < .001). In multivariate regression modeling, only transpulmonary gradient and heart rate were independent determinants of PAAT. PAAT ≤77 msec had acceptable utility for diagnosing PVRi ≥ 3 Wu*m2 (AUC .8 [.64, .95], n = 36), low sensitivity (59%), and excellent specificity (94%). CONCLUSION: Transpulmonary gradient and heart rate, but not pulmonary blood flow, are important determinants of PAAT in children <36 months undergoing cardiac catheterization. PAAT has low sensitivity for diagnosing elevated PVRi, therefore, should not be solely relied upon in screening for elevated PVRi in young children.

Doppler Echocardiographic Features of Pulmonary Vein Stenosis in Ex-Preterm Children.

BACKGROUND: Echocardiography is used to screen for the presence of pulmonary vein stenosis (PVS) in ex-preterm infants and children. However, there are no standard accepted criteria for screening or diagnosis of PVS by echocardiography. The aim of this study was to identify Doppler waveform features and Doppler systolic and diastolic velocity cutoff values associated with a diagnosis of PVS by cardiac catheterization. METHODS: In this retrospective observational study, the echocardiograms of ex-preterm children <3 years old who underwent cardiac catheterization at a single institution were reviewed. PVS on cardiac catheterization was defined by a mean pressure gradient of >3 mm Hg in the pulmonary vein, with angiographic evidence of stenosis. Pulmonary vein Doppler waveforms, from echocardiograms obtained before catheterization, in children with and without PVS were compared. Nonstenosed veins in patients with PVS were excluded. The systolic and diastolic velocities of blood flow, phasic flow, and return of the Doppler waveform to baseline were analyzed. RESULTS: Forty-seven children were analyzed in the study, 18 children with 25 stenosed pulmonary veins and 29 children with 78 nonstenosed pulmonary veins. Stenosed pulmonary veins had higher peak systolic and diastolic velocities and higher peak and mean pressure gradients as measured by spectral Doppler. Peak systolic and diastolic velocities had areas under the receiver operating characteristic curve of 0.89 (95% CI, 0.79-0.99) and 0.93 (95% CI, 0.85-0.99) for PVS, respectively, and a threshold velocity of 0.7 m/sec had sensitivity of 80% and 84% and specificity of 94%. There was no correlation between Doppler-derived pulmonary vein mean gradient and measured pulmonary vein mean gradient during cardiac catheterization in stenosed pulmonary veins. Presence of phasic flow in the pulmonary vein and return of the Doppler waveform to baseline were associated with a nonstenosed pulmonary vein (sensitivity of 94% and 60% and specificity of 52% and 60%, respectively). CONCLUSIONS: Systolic and diastolic Doppler velocities and features of the waveform can discriminate stenosed pulmonary veins confirmed by cardiac catheterization in ex-preterm children. These results suggest the use of lower systolic and diastolic Doppler velocity cutoff values than currently published to screen for PVS in ex-preterm children. These cutoff values require validation in prospective studies.

Oral Feeding in Infants After Congenital Diaphragmatic Hernia Repair While on Non-invasive Positive Pressure Ventilation: The Impact of a Dysphagia Provider-Led Protocol.

Infants with congenital diaphragmatic hernia (CDH) who require non-invasive positive pressure ventilation or high flow nasal cannula are at risk for aspiration and delayed initiation of oral feeding. We developed a dysphagia provider-led protocol that involved early consultation with an occupational therapist or speech/language pathologist and modified barium swallow study (MBSS) to assess for readiness for oral feeding initiation/advancement on non-invasive positive pressure ventilation. The objective of this study was to retrospectively compare this intervention cohort to a historical control cohort to evaluate the protocol's impact on the time to initiate oral feeding. We describe the development and implementation of the protocol, the MBSS findings of the intervention cohort, and compared the control (n = 64) and intervention (n = 37) cohorts using Fischer's exact test and Mann-Whitney test. We found that both cohorts had similar prenatal and neonatal characteristics including age at extubation. Significantly more infants in the intervention cohort were on non-invasive positive pressure ventilation or high flow nasal cannula at the time of oral feeding initiation (84% vs. 28%, p < 0.0001). None of the control cohort infants underwent MBSS while on respiratory support. Of the intervention cohort, 15 infants underwent a MBSS while on non-invasive positive pressure ventilation; 6 had no evidence of laryngeal penetration and/or aspiration during swallowing. Infants in the control cohort initiated oral feeds significantly sooner after extubation (6 versus 11 days, p = 0.001) and attained full oral feeds earlier (20 days versus 28 days, p = 0.02) than the intervention group. There was no difference in the rate of gastrostomy tube placement (38%). Appropriate monitoring by a dysphagia provider and evaluation with clinical and radiological means are crucial to determine the safety of initiating oral feeding in term infants with CDH. Continued surveillance is needed to determine the long-term impact on oral feeding progression in this population.

Hemodynamic optimization for neonates with neonatal encephalopathy caused by a hypoxic ischemic event: Physiological and therapeutic considerations.

Neonatal encephalopathy due to a hypoxic-ischemic event is commonly associated with cardiac dysfunction and acute pulmonary hypertension; both therapeutic hypothermia and rewarming modify loading conditions and blood flow. The pathophysiological contributors to disease are complex with a high degree of clinical overlap and traditional bedside measures used to assess circulatory adequacy have multiple confounders. Comprehensive, quantitative echocardiography may be used to delineate the relative contribution of lung parenchymal, pulmonary vascular, and cardiac disease to hypotension and/or hypoxemic respiratory failure. In this review, we provide a detailed overview of the contributors to hemodynamic instability following perinatal hypoxic-ischemic injury. Our proposed approach to therapy focuses on physiopathological considerations with interventions individualized to this potentially complex condition and considers the pharmacological idiosyncrasies, which may occur among neonates with NE presenting with multiorgan dysfunction while undergoing therapeutic hypothermia.

Outcomes of Very Preterm Infants Conceived with Assisted Reproductive Technologies.

OBJECTIVE: To compare mortality and early respiratory outcomes of very preterm infants conceived via assisted reproductive technology (ART) vs spontaneously. STUDY DESIGN: We identified inborn infants (July 2014-July 2019) with gestational age <32 weeks (n = 439); 54 cases were ART conceived. Spontaneously conceived controls (n = 103) were matched by multiple gestation status and gestational age. Primary outcome was 1-year mortality. Secondary outcomes were receipt of respiratory support and supplemental oxygen at 7 and 28 days and 36 weeks of postmenstrual age. We evaluated the association between conception method and outcomes by logistic regression, with adjustment for sociodemographic status. RESULTS: Women who conceived via ART had increased rates of prepregnancy and gestational diabetes, and no differences in rates of hypertensive disorders. Infant 1-year mortality was not different by mode of conception (ART 11.8% vs spontaneous 7.1%, P = .49). Infants conceived by ART were less likely to receive respiratory support or supplemental oxygen at all time points, but this relationship only reached significance for receipt of oxygen at 28 days (ART 20.8% vs spontaneous 39.0%, P = .03); this remained true after adjustment for race/ethnicity and socioeconomic index. CONCLUSIONS: When controlling for gestational age and multiple gestation status, very preterm infants conceived following ART had similar outcomes as those conceived spontaneously.

Association between Z-score for birth weight and postoperative outcomes in neonates and infants with congenital heart disease.

OBJECTIVE: We hypothesized that infants with fetal growth restrictions have increased mortality and morbidity after congenital heart disease surgery. METHODS: The study included patients in The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2016) who underwent cardiac surgery at a corrected gestational age of ≤44 weeks. Patients were classified as severely (birth weight Z-score -4 to -2), moderately (Z-score -2 to -1), and mildly growth restricted (Z-score -1.0 to -0.5) and compared with a reference population (Z-score 0-0.5). Multivariable logistic regression clustering on center was used to evaluate the association of birth weight Z-score with operative mortality and postoperative complications and its interaction with gestational age was assessed. RESULTS: In 25,244 patients, operative mortality was 8.6% and major complications occurred in 19.4%. Compared with the reference group, the adjusted odds ratio (AOR) of mortality was increased in infants with severe (AOR, 2.4; 95% confidence interval [CI], 2.0-3.0), moderate (AOR, 1.7; 95% CI, 1.4-2.0), and mild growth restriction (AOR, 1.4; 95% CI, 1.2-1.6). The AOR for major postoperative complications was increased for severe (AOR, 1.4; 95% CI, 1.2-1.7) and moderate growth restriction (AOR, 1.2; 95% CI, 1.1-1.4). There was significant interaction between birth weight Z-score and gestational age (P = .007). CONCLUSIONS: Even birth weight Z-scores slightly below average are independent risk factors for mortality and morbidity in infants who undergo cardiac surgery. The strongest association between poor fetal growth and operative mortality exists in early-term infants. These novel findings might account for some of the previously unexplained variation in cardiac surgical outcomes.

Pulmonary hypertension is an important co-morbidity in developmental lung diseases of infancy: Bronchopulmonary dysplasia and congenital diaphragmatic hernia.

Bronchopulmonary dysplasia (BPD) following preterm birth and congenital diaphragmatic hernia (CDH) are both forms of developmental lung disease that may result in persistent pulmonary and pulmonary vascular morbidity in childhood. The pulmonary vascular disease (PVD) which accompanies BPD and CDH is due to developmental abnormalities and ongoing perinatal insults. This may be accompanied by evidence of elevated right heart pressures and pulmonary vascular resistance, leading to diagnosis of pulmonary hypertension (PH). The development of PH in these conditions is associated with increased morbidity and mortality in the vulnerable BPD and CDH populations. We present a review of PVD pathogenesis and evaluation in BPD and CDH and discuss management of related sequelae of PH co-morbidity for affected infants.

Infant Outcomes Following Maternal Infection With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): First Report From the Pregnancy Coronavirus Outcomes Registry (PRIORITY) Study.

Infant outcomes after maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are not well described. In a prospective US registry of 263 infants, maternal SARS-CoV-2 status was not associated with birth weight, difficulty breathing, apnea, or upper or lower respiratory infection through 8 weeks of age.

Bronchopulmonary dysplasia precursors influence risk of white matter injury and adverse neurodevelopmental outcome in preterm infants.

BACKGROUND: Cumulative supplemental oxygen (CSO) and cumulative mean airway pressure (CMAP) are associated with bronchopulmonary dysplasia (BPD) in preterm infants, but their relationships to white matter injury (WMI) and neurodevelopment have not been evaluated. METHODS: Preterm infants <32 weeks' gestation were prospectively imaged with 3 T MRI near term. CSO and CMAP were retrospectively summed over the first 14 and 28 days. Neurodevelopment was assessed at 30 months adjusted using the Bayley-III. ROC and linear regression were used to evaluate the relationship between CSO, CMAP, and BPD with WMI and neurodevelopmental performance, respectively. RESULTS: Of the 87 infants, 30 (34.5%) had moderate-severe BPD, which was associated with WMI (OR 5.5, 95% CI 1.1-34.9, p = 0.012). CSO and CMAP predicted WMI as well as BPD (AUC 0.68-0.77). CSO was independently associated with decreased language and cognitive performance (mean difference at 14 days: -11.0, 95% CI -19.8 to -2.2, p = 0.015 and -9.8, 95% CI -18.9 to -0.7, p = 0.035, respectively) at 30 months adjusted. CONCLUSIONS: BPD precursors predict WMI as well as BPD. Cumulative supplemental oxygen over the first 14 days of life is independently associated with lower language and cognitive performances. These data suggest that early respiratory status influences the risk of adverse neurodevelopment in preterm infants. IMPACT: Respiratory precursors to bronchopulmonary dysplasia (BPD), cumulative supplemental oxygen and mean airway pressure, over the first 14-28 days performed as well as BPD for the prediction of white matter injury on MRI in preterm infants. Cumulative supplemental oxygen was independently associated with lower language and cognitive performance on the Bayley-III at 30 months adjusted. These data suggest that early respiratory status may help explain why BPD is independently associated with adverse neurodevelopmental outcomes in the preterm population and highlights the importance of interventions targeting respiratory status as a potential avenue to improve neurodevelopmental outcomes.

Predicting NICU admissions in near-term and term infants with low illness acuity.

OBJECTIVE: Describe NICU admission rate variation among hospitals in infants with birthweight ≥2500 g and low illness acuity, and describe factors that predict NICU admission. STUDY DESIGN: Retrospective study from the Vizient Clinical Data Base/Resource Manager®. Support vector machine methodology was used to develop statistical models using (1) patient characteristics (2) only the indicator for the inborn hospital and (3) patient characteristics plus indicator for the inborn hospital. RESULTS: NICU admission rates of 427,449 infants from 154 hospitals ranged from 0 to 28.6%. C-statistics for the patient characteristics model: 0.64 (Confidence Interval (CI) 0.62-0.65), hospital only model: 0.81 (CI, 0.81-0.82), and patient characteristic plus hospital variable model: 0.84 (CI, 0.83-0.84). CONCLUSION/RELEVANCE: There is wide variation in NICU admission rates in infants with low acuity diagnoses. In all cohorts, birth hospital better predicted NICU admission than patient characteristics alone.