The validity of the observed-to-expected lung-to-head ratio in congenital diaphragmatic hernia in an era of standardized neonatal treatment; a multicenter study

Comparison of current to past outcomes in congenital diaphragmatic hernia using mri observed-to-expected total fetal lung volume

BACKGROUND

Fetal Centers use imaging studies to predict congenital diaphragmatic hernia (CDH) prognosis and the need for fetal therapy. Given improving CDH survival, we hypothesized that current fetal imaging severity predictions no longer reflect true outcomes and fail to justify the risks of fetal therapy.

METHODS

We analyzed our single-center contemporary data in a left-sided CDH cohort (n = 58) by prognostic criteria determined by MRI observed-to-expected total fetal lung volumes: severe <25%, moderate 25-35%, and mild >35%. We compared contemporary survival to prior studies and the TOTAL trials.

RESULTS

Contemporary survival was significantly higher than past studies for all prognostic classifications (mild 100% vs 80-94%, moderate 95% vs 59-75%, severe 79% vs 13-25%; P < 0.01), and to either control or fetal therapy arms of the TOTAL trials.

CONCLUSIONS

Current fetal imaging criteria are overly pessimistic and may lead to unwarranted fetal intervention. Fetal therapies remain experimental. Future studies will require updated prognostic criteria.

The role of extracorporeal life support and timing of repair in infants with congenital diaphragmatic hernia

Extracorporeal life support (ECLS) serves as a rescue therapy for patients with congenital diaphragmatic hernia (CDH) and severe cardiopulmonary failure, and only half of these patients survive to discharge. This costly intervention has a significant complication risk and is reserved for patients with the most severe disease physiology refractory to maximal cardiopulmonary support. Some contraindications to ECLS do exist such as coagulopathy, lethal chromosomal or congenital anomaly, very preterm birth, or very low birth weight, but many of these limits are being evaluated through further research. Consensus guidelines from the past decade vary in recommendations for ECLS use in patients with CDH but this therapy appears to have a survival benefit in the most severe subset of patients. Improved outcomes have been observed for patients treated at high-volume centers. This review details the evolving literature surrounding management paradigms for timing of CDH repair for patients receiving preoperative ECLS. Most recent data support early repair following cannulation to avoid non-repair which is uniformly fatal in this population. Longer ECLS runs are associated with decreased survival, and patient physiology should guide ECLS weaning and eventual decannulation rather than limiting patients to arbitrary run lengths. Standardization of care across centers is a major focus to limit unnecessary costs and improve short-term and long-term outcomes for these complex patients.

Pulmonary vasculature development in congenital diaphragmatic hernia: a novel automated quantitative imaging analysis

PURPOSE

Impaired fetal lung vasculature determines the degree of pulmonary hypertension in the congenital diaphragmatic hernia (CDH). This study aims to demonstrate the morphometric measurements that differ in pulmonary vessels of fetuses with CDH.

METHODS

Nitrofen-induced CDH Sprague-Dawley rat fetuses were scanned with microcomputed tomography. The analysis of the pulmonary vascular tree was performed with artificial intelligence.

RESULTS

The number of segments in CDH was significantly lower than that in the control group on the left (U = 2.5, p = 0.004) and right (U = 0, p = 0.001) sides for order 1(O1), whereas there was a significant difference only on the right side for O2 and O3. The pooled element numbers in the control group obeyed Horton's law (R2 = 0.996 left and R2 = 0.811 right lungs), while the CDH group broke it. Connectivity matrices showed that the average number of elements of O1 springing from elements of O1 on the left side and the number of elements of O1 springing from elements of O3 on the right side were significantly lower in CDH samples.

CONCLUSION

According to these findings, CDH not only reduced the amount of small order elements, but also destroyed the fractal structure of the pulmonary arterial trees.

The Delivery Room Resuscitation of Infants with Congenital Diaphragmatic Hernia Treated with Fetoscopic Endoluminal Tracheal Occlusion: Beyond the Balloon

INTRODUCTION

Randomized controlled trials found that fetoscopic endoluminal tracheal occlusion (FETO) resulted in increased fetal lung volume and improved survival for infants with isolated, severe left-sided congenital diaphragmatic hernia (CDH). The delivery room resuscitation of these infants is particularly unique, and the specific delivery room events are largely unknown. The objective of this study was to compare the delivery room resuscitation of infants treated with FETO to standard of care (SOC) and describe lessons learned.

METHODS

Retrospective single-center cohort study of infants treated with FETO compared to infants who met FETO criteria during the same period but who received SOC.

RESULTS

FETO infants were more likely to be born prematurely with 8/12 infants born <35 weeks gestational age compared to 3/35 SOC infants. There were 5 infants who required emergent balloon removal (2 ex utero intrapartum treatment and 3 tracheoscopic removal on placental bypass with delayed cord clamping) and 7 with prenatal balloon removal. Surfactant was administered in 6/12 FETO (50%) infants compared to 2/35 (6%) in the SOC group. Extracorporeal membrane oxygenation use was lower at 25% and survival was higher at 92% compared to 60% and 71% in the SOC infants, respectively.

CONCLUSION

The delivery room resuscitation of infants treated with FETO requires thoughtful preparation with an experienced multidisciplinary team. Given increased survival, FETO should be offered to infants with severe isolated left-sided CDH, but only in high-volume centers with the experience and capability of removing the balloon, emergently if needed. The neonatal clinical team must be skilled in managing the unique postnatal physiology inherent to FETO where effective interdisciplinary teamwork is essential. Empiric and immediate surfactant administration should be considered in all FETO infants to lavage thick airway secretions, particularly those delivered <48 h after balloon removal.

Early echocardiographic pulmonary artery measurements as prognostic indicators in left congenital diaphragmatic hernia

BACKGROUND

To predict whether the left pulmonary artery (LPA) to the main pulmonary artery (MPA) ratio measured by echocardiography in left congenital diaphragmatic hernia (CDH) was related to death or need for extracorporeal membrane oxygenation (ECMO).

METHODS

This retrospective study analyzed neonates with left CDH born between 2018 and 2022 in a single tertiary medical institution. Echocardiography was performed immediately after birth. The diameter of the LPA was measured at the bifurcation, and the diameter of the MPA was measured at the maximal dimension during the systolic phase. The Nakata index, McGoon ratio, and ejection fraction (EF) were analyzed and compared with the LPA: MPA ratio as predictive values.

RESULTS

Seventy-two neonates with left CDH were included, 19 (26.4%) died or needed ECMO, and 53 (73.6%) survived without ECMO. The lower observed/expected lung-to-head ratio, lower EF, lower LPA: MPA ratio, lower RPA: MPA ratio, lower Nakata index, and lower McGoon ratio were associated with death or need for ECMO. By multivariate analysis, lower LPA: MPA ratio, RPA: MPA ratio, and Nakata index were independent postnatal risk factors for death or need for ECMO. Among the measurements, the LPA: MPA ratio had the highest area under the curve (0.957) with a sensitivity of 84.2% and specificity of 96.3% at a cut-off value of 31.2%.

CONCLUSION

In patients with left CDH, the LPA: MPA ratio measured by echocardiography could be used as an independent postnatal predictor of death or need for ECMO.

Respiratory function after birth in infants with congenital diaphragmatic hernia

OBJECTIVE

To characterise the transitional pulmonary physiology of infants with congenital diaphragmatic hernia (CDH) using measures of expiratory tidal volume (TV) and end-tidal carbon dioxide (ETCO2).

DESIGN

Prospective single-centre observational study.

SETTING

Quaternary neonatal intensive care unit.

PATIENTS

Infants with an antenatal diagnosis of CDH born at the Children's Hospital of Philadelphia.

INTERVENTIONS

TV and ETCO2 were simultaneously recorded using a respiratory function monitor (RFM) during invasive positive pressure ventilation immediately after birth.

MAIN OUTCOME MEASURES

TV per birth weight and ETCO2 values were summarised for each minute after birth. Subgroups of interest were defined by liver position (thoracic vs abdominal) and extracorporeal membrane oxygenation (ECMO) treatment.

RESULTS

RFM data were available for 50 infants from intubation until a median (IQR) of 9 (7-14) min after birth. TV and ETCO2 values increased for the first 10 min after birth, but intersubject values were heterogeneous. TVs were overall lower and ETCO2 values higher in infants with an intrathoracic liver and infants who were ultimately treated with ECMO. On hospital discharge, survival was 88% (n=43) and 34% (n=17) of infants were treated with ECMO.

CONCLUSION

Respiratory function immediately after birth is heterogeneous for infants with CDH. Lung aeration, as evidenced by expired TV and ETCO2, appears to be ongoing throughout the first 10 min after birth during invasive positive pressure ventilation. Close attention to expired TV and ETCO2 levels by 10 min after birth may provide an opportunity to optimise and individualise ventilatory support for this high-risk population.

Prenatal assessment of pulmonary vasculature development in fetuses with congenital diaphragmatic hernia: A literature review

Pathophysiological studies have shown that pulmonary vascular development is impaired in fetuses with a congenital diaphragmatic hernia (CDH), leading to a simplified vascular tree and increased vascular resistance. Multiple studies have described prenatal ultrasound parameters for the assessment of the pulmonary vasculature, but none of these parameters are used in daily clinical practice. We provide a comprehensive review of the literature published between January 1990 and February 2022 describing these parameters, and aim to explain the clinical relevance of these parameters from what is known from pathophysiological studies. Prenatal detection of a smaller diameter of the contralateral (i.e. contralateral to the diaphragmatic defect) first branch of the pulmonary artery (PA), higher pulsatility indices (PI), higher peak early diastolic reverse flow values, and a lower vascularization index seem of added value for the prediction of survival and, to a lesser extent, morbidity. Integration within the routine evaluation is complicated by the lack of uniformity of the methods used. To address the main components of the pathophysiological changes, we recommend future prenatal studies in CDH with a focus on PI values, PA diameters and pulmonary vascular branching.

Sex-Specific Differences in Congenital Diaphragmatic Hernia Mortality

OBJECTIVE

To compare disease severity and mortality differences between female and male patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We queried the CDH Study Group (CDHSG) database for CDH neonates managed between 2007 and 2018. Female and males were compared in statistical analyses using t tests, χ² tests, and Cox regression, as appropriate (P ≤ .05).

RESULTS

There were 7288 CDH patients, of which 3048 (41.8%) were female. Females weighed less on average at birth than males (2.84 kg vs 2.97 kg, P < .001) despite comparable gestational age. Females had similar rates of extracorporeal life support (ECLS) utilization (27.8% vs 27.3%, P = .65). Although both cohorts had equivalent defect size and rates of patch repair, female patients had increased rates of intrathoracic liver herniation (49.2% vs 45.9%, P = .01) and pulmonary hypertension (PH) (86.6% vs 81.1%, P < .001). Females had lower survival rates at 30-days (77.3% vs 80.1%, P = .003) and overall lower survival to discharge (70.2% vs 74.2%, P < .001). Subgroup analysis revealed that increased mortality was significant among those who underwent repair but were never supported on ECLS (P = .005). On Cox regression analysis, female sex was independently associated with mortality (adjusted hazard ratio 1.32, P = .02).

CONCLUSION

After controlling for the established prenatal and postnatal predictors of mortality, female sex remains independently associated with a higher risk of mortality in CDH. Further study into the underlying causes for sex-specific disparities in CDH outcomes is warranted.

One Size Does Not Fit All: Congenital Diaphragmatic Hernia Management in Neonates

Congenital diaphragmatic hernia (CDH) results from abnormal development of the diaphragm during fetal life, allowing abdominal organs to herniate through the defect into the thorax. Stunted lung growth is associated with pulmonary hypoplasia and pulmonary hypertension, which are the primary sources of morbidity and mortality for this population. Despite strides in neonatal and surgical care, the management of neonates with CDH remains challenging. Optimal treatment strategies are still largely unknown. Many centers utilize gentle ventilation, permissive hypercapnia, and pulmonary hypertension treatment inclusive of nitric oxide, sildenafil, or epoprostenol, delayed surgical repair, and extracorporeal membrane oxygenation (ECMO). Evidence-based guidelines are needed to enhance CDH care practices and better outcomes. The successful management of CDH is a collaborative team effort from the prenatal to the postnatal period and beyond.

Termination of pregnancy after a prenatal diagnosis of congenital diaphragmatic hernia: Factors influencing the parental decision process

OBJECTIVE

To evaluate the incidence of termination of pregnancies (TOP) and factors associated with the decision for TOP in prenatally detected congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Single-centre retrospective cohort includes all prenatally detected CDH cases born between January 2009 and December 2021. Parental factors, such as parity, and fetal characteristics, such as disease severity, were collected. Descriptive statistics were used to present the data. Differences between terminated and continued pregnancies were analysed.

RESULTS

The study population consisted of 278 prenatally detected CDH cases of which 80% detected <24 weeks of gestation. The TOP rate was 28% in cases that were detected <24 weeks of gestation. Twenty continued pregnancies resulted in either intrauterine fetal demise (n = 6), preterm birth <24 weeks (n = 2), or comfort care after birth (n = 12). The survival rate was 70% in the remaining 195 live born cases. Factors associated with the decision for TOP were additional fetal genetic or anatomical abnormalities (p < 0.0001) and expected severity of pulmonary hypoplasia in left-sided CDH (p = 0.0456).

CONCLUSION

The decision to terminate a pregnancy complicated by fetal CDH depends on the severity of pulmonary hypoplasia and the presence of additional abnormalities. This emphasises the importance of early referral to expertise centres for detailed evaluation and multidisciplinary counselling.

Prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia: a systematic review and meta-analysis

PURPOSE

This study aimed to evaluate prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia (CDH).

METHODS

A systematic literature search was performed to identify relevant observational studies that evaluated the ability of lung-to-head ratio (LHR), observed-to-expected LHR (o/e-LHR), observed-to-expected total fetal lung volume (o/e-TFLV), lung-to-thorax transverse area ratio (L/T ratio), intrathoracic herniation of the liver and the stomach, and side of diaphragmatic hernia, using a threshold for the prediction of mortality in fetuses with CDH. Study quality was assessed using the QUADAS-2 tool. Hierarchical summary receiver operating characteristic curves were constructed.

RESULTS

A total of 50 articles were included in this meta-analysis. The QUADAS-2 tool identified a high risk of bias in more than one domain scored in all parameters. Among those parameters, the diagnostic odds ratio of mortality with o/e-LHR < 25%, o/e-TFLV < 25%, and L/T ratio < 0.08 were 11.98 [95% confidence interval (CI) 4.65-30.89], 11.14 (95% CI 5.19-23.89), and 10.28 (95% CI 3.38-31.31), respectively. The predictive values for mortality were similar between the presence of liver herniation and retrocardiac fetal stomach position.

CONCLUSIONS

This systematic review suggests that o/e-LHR, o/e-TFLV, and L/T ratio are equally good predictors of neonatal mortality in fetuses with isolated CDH.

Postnatal care setting and survival after fetoscopic tracheal occlusion for severe congenital diaphragmatic hernia: A systematic review and meta-analysis

BACKGROUND

Fetoscopic endoluminal tracheal occlusion (FETO) was recently shown to improve postnatal survival in a multicenter, randomized controlled trial of infants with severe congenital diaphragmatic hernia (CDH). However, the external validity of this study remains unclear given a lack of standardization in postnatal management approaches. The purpose of this study was to evaluate the impact of an integrated prenatal and postnatal care setting on survival outcomes in severe CDH after FETO.

STUDY DESIGN

A systematic review, meta-analysis, and individual participant analysis of FETO outcomes in severe CDH were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The primary outcome was survival to discharge. Subgroup analyses of patients managed in integrated versus nonintegrated settings were performed to identify predictors of outcome.

RESULTS

The review generated five studies (n = 192) for the meta-analysis of FETO versus expectant prenatal management. These data revealed a significant survival benefit after FETO that was restricted to an integrated setting (OR 2.97, 95% Confidence Interval 1.69-4.26). There were nine studies (n = 150) for the individual participant analysis, which showed that FETO managed in an integrated setting had significantly increased survival rates when compared to FETO treated in a nonintegrated setting (70.7% vs. 45.7%, p = 0.003). Multi-level logistic regression identified increased availability of extracorporeal membrane oxygenation (ECMO) as the strongest determinant of postnatal survival (OR=18.8, p = 0.049).

CONCLUSION

This systematic review shows that institutional integration of prenatal and postnatal care is associated with the highest overall survival in children with severe CDH. These data highlight the importance of a standardized, multidisciplinary approach, including access to ECMO, as a critical postnatal component in optimizing FETO outcomes in CDH.

Image-based prenatal predictors correlate with postnatal survival, extracorporeal life support use, and defect size in left congenital diaphragmatic hernia

OBJECTIVE

To evaluate the association between prenatal imaging predictors of patients with left-sided congenital diaphragmatic hernia (LCDH) and postnatal outcomes.

STUDY DESIGN

CDH study group data were reviewed for LCDH infants born 2015-2019. Prenatal ultrasound (US) and magnetic resonance imaging (MRI) data were collected and correlated with postnatal information including CDHSG defect size (A through D or non-repair (NR)).

RESULTS

In total, 929 LCDH patients were included. Both US and MRI imaging predictors correlated with postnatal survival (72.2%) and ECLS use (29.6%). Logistic regression models confirmed increased survival and decreased ECLS use with larger values for all predictors. Importantly, all prenatal values evaluated showed no significant difference between defect size D and NR patients.

CONCLUSIONS

This is the largest cohort of LCDH patients and demonstrates that prenatal imaging factors correlate with postnatal outcomes and confirms that patients in the non-repair group are prenatally similar to type D defects.

Small prenatal diameter of the ascending aorta is associated with increased mortality risk in neonates with congenital diaphragmatic hernia

INTRODUCTION

The aim of this study was to evaluate whether selected prenatal markers obtained from fetal echocardiography can predict postnatal outcome in congenital diaphragmatic hernia (CDH) patients. We also aimed to verify the prognostic value of lung-to-head ratio (LHR).

MATERIAL AND METHODS

The study group included 29 fetuses with CDH. We analyzed potentially prognostic parameters measured using fetal echocardiography and fetal ultrasound. The assessed parameters were compared between the group of patients with CDH who survived to discharge (n = 21) and the subset of patients who died before discharge from hospital (n = 8).

RESULTS

In survivors, mean z-score for ascending aorta (AAo) diameter was 0.23 ±0.98 vs. - 1.82 ±1.04 in patients who died (t-test, p = 0.0015). In survivors, the main pulmonary artery/ascending aorta ratio was 1.22 ±0.17 vs. 1.46 ±0.21 in patients who died (t-test, p = 0.017). In survivors, the LHR was 1.81 ±0.96 vs. 0.95 ±0.6 in patients who died (t-test, p = 0.019). In survivors, the observed to expected LHR was 57 ±30% vs 30 ±18% in patients who died (t-test, p = 0.018).

CONCLUSIONS

Narrowing of the ascending aorta in CDH fetuses is a poor prognostic factor associated with increased mortality in neonates. Our study also confirmed the prognostic value of LHR.

Spontaneous breathing approach in mild congenital diaphragmatic hernia: A resuscitation algorithm

BACKGROUND

Infants with a congenital diaphragmatic hernia (CDH) and expected mild pulmonary hypoplasia have an estimated survival rate of 90%. Current guidelines for delivery room management do not consider the individual patient's disease severity, but an individualized approach with spontaneous breathing instead of routine mechanical ventilation could be beneficial for the mildest cases. We developed a resuscitation algorithm for this individualized approach serving two purposes: improving the success rate by structuring the approach and providing a guideline for other centers.

METHODS

An initial algorithm was discussed with all local stakeholders. Afterwards, the resulting algorithm was refined using input from international experts.

RESULTS

Eligible CDH infants: left-sided defect, observed to expected lung-to-head ratio ≥50%, gestational age at birth ≥37.0 weeks, and no major associated structural or genetic abnormalities. To facilitate fetal-to-neonatal transition, we propose to start stabilization with non-invasive respiratory support and to adjust this individually.

CONCLUSIONS

Infants with mild CDH might benefit from an individualized approach for neonatal resuscitation. Herein, we present an algorithm that could serve as guidance for centers implementing this.

Prediction of neonatal survival according to lung-to-head ratio in fetuses with right congenital diaphragmatic hernia (CDH): A multicentre study from the Latin American CDH Study Group registry

OBJECTIVE

To evaluate survival outcomes of fetuses with right sided congenital diaphragmatic hernia (CDH) treated in Latin American centres and to assess the utility of left lung area to predict neonatal survival.

METHODS

A retrospective cohort including isolated right sided CDH cases managed expectantly during pregnancy in six tertiary centers from five Latin American countries. The utility of the observed/expected lung-to-head ratio (O/E-LHR) in predicting neonatal survival was assessed, and the best cut-off to predict prognosis was automatically selected by decision tree analysis.

RESULTS

A total of 99 right sided CDH cases were recruited, 58 isolated fetuses were selected at a median gestational age of 26.2 weeks, showing an overall survival rate of 26.2%. A linear trend was observed between survival and the O/E-LHR, showing that at higher O/E-LHR, the greater probability of survival (r = 0.56, p < 0.001). O/E-LHR discriminates two groups with different survival outcomes: fetuses with an O/E-LHR ≥65% showed a significantly higher survival rate than those with an O/E-LHR <65% (81.8% vs. 15.6%, p < 0.01).

CONCLUSIONS

Overall survival rate in right sided CDH is lower in Latin American countries. The severity category of pulmonary hypoplasia should be classified according to lung area and the survival rate in such population.

Genetic Diagnostic Strategies and Counseling for Families Affected by Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a relatively common and severe birth defect with variable clinical outcome and associated malformations in up to 60% of patients. Mortality and morbidity remain high despite advances in pre-, intra-, and postnatal management. We review the current literature and give an overview about the genetics of CDH to provide guidelines for clinicians with respect to genetic diagnostics and counseling for families. Until recently, the common practice was (molecular) karyotyping or chromosome microarray if the CDH diagnosis is made prenatally with a 10% diagnostic yield. Undiagnosed patients can be reflexed to trio exome/genome sequencing with an additional diagnostic yield of 10 to 20%. Even with a genetic diagnosis, there can be a range of clinical outcomes. All families with a child with CDH with or without additional malformations should be offered genetic counseling and testing in a family-based trio approach.

Intrapulmonary artery Doppler to predict mortality and morbidity in fetuses with mild or moderate left-sided congenital diaphragmatic hernia

OBJECTIVES

In fetuses with isolated left-sided congenital diaphragmatic hernia (LCDH), prenatal detection of severe pulmonary hypoplasia is important, as fetal therapy can improve survival. Cases with mild or moderate lung hypoplasia still carry a considerable risk of mortality and morbidity, but there has been less interest in the accurate prediction of outcome in these cases. In this study of fetuses with mild or moderate isolated LCDH, we aimed to investigate: (1) the association between intrapulmonary artery (IPA) Doppler findings and mortality at discharge; (2) whether adding IPA Doppler findings improves the prediction of mortality based on lung size and liver herniation; and (3) the association between IPA Doppler findings and early neonatal morbidity.

METHODS

This was a retrospective study of all consecutive fetuses assessed at the BCNatal and UZ Leuven hospitals between 2008 and 2020 with a prenatal diagnosis of isolated, non-severe LCDH, defined as observed-to-expected lung-to-head ratio (o/e-LHR) > 25%, that were managed expectantly during pregnancy followed by standardized neonatal management. An additional inclusion criterion was the availability of IPA Doppler measurements. The primary outcome was the association between IPA Doppler findings and mortality at discharge. Other predictors included o/e-LHR, liver herniation and gestational age at birth. Secondary outcomes were the association between IPA Doppler findings and the presence of pulmonary hypertension (PHT), need for supplemental oxygen at discharge and need for extracorporeal membrane oxygenation. IPA pulsatility index (PI) values were converted into Z-scores. Logistic regression analysis was performed to investigate the associations between predictor variables and outcome, and the best model was chosen based on the Nagelkerke R² .

RESULTS

Observations for 70 non-severe LCDH cases were available. Fifty-four (77%) fetuses survived until discharge. On logistic regression analysis, higher IPA-PI was associated with an increased risk of mortality (odds ratio (OR), 3.96 (95% CI, 1.62-9.70)), independently of o/e-LHR (OR, 0.87 (95% CI, 0.79-0.97)). An IPA-PI Z-score cut-off of 1.8 predicted mortality with a detection rate of 69% and specificity of 93%. Adding IPA-PI to o/e-LHR improved significantly the model's performance (Nagelkerke R² , 46% for o/e-LHR + IPA-PI vs 28% for o/e-LHR (P < 0.002)), with a detection rate of 81% at a 10% false-positive rate. IPA-PI was associated with PHT (OR, 2.20 (95% CI, 1.01-4.59)) and need for oxygen supplementation at discharge (OR, 1.90 (95% CI, 1.10-3.40)), independently of lung size.

CONCLUSIONS

In fetuses with mild or moderate LCDH, IPA-PI was associated with mortality and morbidity, independently of lung size. A model combining o/e-LHR with IPA-PI identified up to four in five cases that eventually died, despite being considered to have non-severe pulmonary hypoplasia. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal liver and lung volume index of neonatal survival with congenital diaphragmatic hernia

BACKGROUND

Magnetic resonance imaging (MRI) assesses pulmonary hypoplasia in fetal congenital diaphragmatic hernia (CDH). Neonatal mortality may occur with CDH.

OBJECTIVE

To quantify MRI parameters associated with neonatal survival in fetuses with isolated CDH.

MATERIALS AND METHODS

Fetal MRI for assessing CDH included region of interest (ROI) measurements for total lung volume (TLV), herniated liver volume, herniated other organ volume and predicted lung volume. Ratios of observed lung volume and liver up volume to predicted lung volume (observed to predicted TLV, percentage of the thorax occupied by liver) were calculated and compared to neonatal outcomes. Analyses included Wilcoxon rank sum test, multivariate logistic regression and receiver operating characteristic (ROC) curves.

RESULTS

Of 61 studies, the median observed to predicted TLV was 0.25 in survivors and 0.16 in non-survivors (P=0.001) with CDH. The median percentage of the thorax occupied by liver was 0.02 in survivors and 0.22 in non-survivors (P<0.001). The association of observed to predicted TLV and percentage of the thorax occupied by liver with survival for gestational age (GA) >28 weeks was greater compared to GA ≤28 weeks. The ROC analysis demonstrated an area under the curve of 0.96 (95% confidence interval 0.91-1.00) for the combined observed to predicted TLV, percentage of the thorax occupied by liver and GA.

CONCLUSION

The percentage of the thorax occupied by liver and observed to predicted TLV was predictive of neonatal survival in fetuses with CDH.

Prenatal stomach position and volume in relation to postnatal outcomes in left-sided congenital diaphragmatic hernia

Objective

To examine the association between prenatal stomach position (SP) grade and stomach volume (SV) and the need for pulmonary hypertension (PH) treatment after birth in prenatally diagnosed left‐sided congenital diaphragmatic hernia (CDH), live born >34 weeks.

Methods

In retrospect, SP grade and SV were determined in fetuses with isolated left‐sided CDH from 19 weeks gestational age (GA) onwards at three different time periods (≤24 weeks' GA: US1, 24–30 weeks' GA: US2; ≥30 weeks' GA: US3). Primary outcome was need for treatment of PH after birth. Secondary analyses included the predictive value of SP and SV for other respiratory outcomes and postnatal defect size.

Results

A total of 101 fetuses were included. SP grade was significantly associated with need for treatment of PH (US1, US2, and US3: p < 0.02). Also, prenatal SP grade was positively associated with defect size and development of chronic lung disease (CLD) in survivors. No association was found between SV and respiratory morbidities or postnatal defect size.

Conclusion

SP grade in left‐sided CDH fetuses is associated with an increased need for PH treatment, a larger postnatal defect size and CLD in survivors. We consider SP determination a valuable contribution to the prenatal assessment of left‐sided CDH.

What is already known about this topic?

Prenatal stomach position (SP) grade has been proposed as a predictive ultrasound parameter for postnatal survival, patch repair, need for extracorporeal membrane oxygenation and need for prolonged respiratory support in left‐sided congenital diaphragmatic hernia (CDH).

What does this study add?

In children with left‐sided CDH, prenatal SP grade is associated with an increase in need for treatment of pulmonary hypertension and development of chronic lung disease, with the greatest increase in SP Grade 2 and 4.

A higher prenatal SP grade is associated with a larger postnatal defect size.

In the majority of cases SP grade does not vary throughout gestation.

Randomized Trial of Fetal Surgery for Moderate Left Diaphragmatic Hernia

BACKGROUND

Fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased postnatal survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data are lacking to inform its effects in infants with moderate disease.

METHODS

In this open-label trial conducted at many centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with a moderate isolated congenital diaphragmatic hernia on the left side to FETO at 30 to 32 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcomes were infant survival to discharge from a neonatal intensive care unit (NICU) and survival without oxygen supplementation at 6 months of age.

RESULTS

In an intention-to-treat analysis involving 196 women, 62 of 98 infants in the FETO group (63%) and 49 of 98 infants in the expectant care group (50%) survived to discharge (relative risk , 1.27; 95% confidence interval [CI], 0.99 to 1.63; two-sided P = 0.06). At 6 months of age, 53 of 98 infants (54%) in the FETO group and 43 of 98 infants (44%) in the expectant care group were alive without oxygen supplementation (relative risk, 1.23; 95% CI, 0.93 to 1.65). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (44% vs. 12%; relative risk, 3.79; 95% CI, 2.13 to 6.91), as was the incidence of preterm birth (64% vs. 22%, respectively; relative risk, 2.86; 95% CI, 1.94 to 4.34), but FETO was not associated with any other serious maternal complications. There were two spontaneous fetal deaths (one in each group) without obvious cause and one neonatal death that was associated with balloon removal.

CONCLUSIONS

This trial involving fetuses with moderate congenital diaphragmatic hernia on the left side did not show a significant benefit of FETO performed at 30 to 32 weeks of gestation over expectant care with respect to survival to discharge or the need for oxygen supplementation at 6 months. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT00763737.).

Management of Congenital Diaphragmatic Hernia (CDH): Role of Molecular Genetics

Congenital diaphragmatic hernia (CDH) is a relatively common major life-threatening birth defect that results in significant mortality and morbidity depending primarily on lung hypoplasia, persistent pulmonary hypertension, and cardiac dysfunction. Despite its clinical relevance, CDH multifactorial etiology is still not completely understood. We reviewed current knowledge on normal diaphragm development and summarized genetic mutations and related pathways as well as cellular mechanisms involved in CDH. Our literature analysis showed that the discovery of harmful de novo variants in the fetus could constitute an important tool for the medical team during pregnancy, counselling, and childbirth. A better insight into the mechanisms regulating diaphragm development and genetic causes leading to CDH appeared essential to the development of new therapeutic strategies and evidence-based genetic counselling to parents. Integrated sequencing, development, and bioinformatics strategies could direct future functional studies on CDH; could be applied to cohorts and consortia for CDH and other birth defects; and could pave the way for potential therapies by providing molecular targets for drug discovery.

Management of Congenital Diaphragmatic Hernia Treated With Extracorporeal Life Support: Interim Guidelines Consensus Statement From the Extracorporeal Life Support Organization

The management of infants with congenital diaphragmatic hernia (CDH) receiving extracorporeal life support (ECLS) is complex. Significant variability in both practice and prevalence of ECLS use exists among centers, given the lack of evidence to guide management decisions. The purpose of this report is to review existing evidence and develop management recommendations for CDH patients treated with ECLS. This article was developed by the Extracorporeal Life Support Organization CDH interest group in cooperation with members of the CDH Study Group and the Children's Hospitals Neonatal Consortium.

Unraveling the Genetics of Congenital Diaphragmatic Hernia: An Ongoing Challenge

Congenital diaphragmatic hernia (CDH) is a congenital structural anomaly in which the diaphragm has not developed properly. It may occur either as an isolated anomaly or with additional anomalies. It is thought to be a multifactorial disease in which genetic factors could either substantially contribute to or directly result in the developmental defect. Patients with aneuploidies, pathogenic variants or de novo Copy Number Variations (CNVs) impacting specific genes and loci develop CDH typically in the form of a monogenetic syndrome. These patients often have other associated anatomical malformations. In patients without a known monogenetic syndrome, an increased genetic burden of de novo coding variants contributes to disease development. In early years, genetic evaluation was based on karyotyping and SNP-array. Today, genomes are commonly analyzed with next generation sequencing (NGS) based approaches. While more potential pathogenic variants are being detected, analysis of the data presents a bottleneck-largely due to the lack of full appreciation of the functional consequence and/or relevance of the detected variant. The exact heritability of CDH is still unknown. Damaging de novo alterations are associated with the more severe and complex phenotypes and worse clinical outcome. Phenotypic, genetic-and likely mechanistic-variability hampers individual patient diagnosis, short and long-term morbidity prediction and subsequent care strategies. Detailed phenotyping, clinical follow-up at regular intervals and detailed registries are needed to find associations between long-term morbidity, genetic alterations, and clinical parameters. Since CDH is a relatively rare disorder with only a few recurrent changes large cohorts of patients are needed to identify genetic associations. Retrospective whole genome sequencing of historical patient cohorts using will yield valuable data from which today's patients and parents will profit Trio whole genome sequencing has an excellent potential for future re-analysis and data-sharing increasing the chance to provide a genetic diagnosis and predict clinical prognosis. In this review, we explore the pitfalls and challenges in the analysis and interpretation of genetic information, present what is currently known and what still needs further study, and propose strategies to reap the benefits of genetic screening.

Discordant prenatal ultrasound and fetal MRI in CDH: wherein lies the truth?

PURPOSE

Prenatal risk assessment of congenital diaphragmatic hernia (CDH) relies on prenatal ultrasound (U/S) and fetal magnetic resonance imaging (MRI). When the modalities differ in prognosis, it is unclear which is more reliable.

METHODS

Retrospective chart review identified cases of prenatally diagnosed CDH from 4/2010-6/2018 meeting inclusion criteria. Demographic, radiologic, and postnatal outcomes data were collected. Ultrasound- versus MRI-based prognosis (mild, moderate, and severe) was compared with clinical outcomes. Kappa measures compared congruency in disease severity scaling between imaging modalities, while logistic regression and receiver operating characteristics curves compared the ability of each modality to predict outcomes.

RESULTS

Forty-two patients met criteria. Both U/S- and MRI-based prognosis categories differentiated for survival. MRI categories differentiated for ECMO use, surgical repair, and defect type. O/e TFLV better discriminated for survivors and defect type than o/e LHR. Seventeen (40.5%) had discordant prenatal prognostic categories. In 13/17 (76.5%), o/e TFLV predicted higher severity when compared to o/e LHR, but sample size was insufficient to compare accuracy in cases of discordance.

CONCLUSIONS

Clinical outcomes suggest fetal MRI may more accurately predict severe pulmonary hypoplasia compared to prenatal ultrasound. Our analysis suggests fetal MRI is a valuable adjunct in the prenatal evaluation of CDH.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective Review.

Tidal volumes at birth as predictor for adverse outcome in congenital diaphragmatic hernia

OBJECTIVE

To assess the predictive value of tidal volume (Vt) of spontaneous breaths at birth in infants with congenital diaphragmatic hernia (CDH).

DESIGN

Prospective study.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS

Thirty infants with antenatally diagnosed CDH born at Hospital Sant Joan de Déu in Barcelona from September 2013 to September 2015.

INTERVENTIONS

Spontaneous breaths and inflations given in the first 10 min after intubation at birth were recorded using respiratory function monitor. Only expired Vt of uninterrupted spontaneous breaths was included for analysis. Receiver operating characteristics (ROC) analysis was performed and the area under the curve (AUC) was estimated to assess the predictive accuracy of Vt.

MAIN OUTCOME MEASURES

Mortality before hospital discharge and chronic lung disease (CLD) at day 28 of life.

RESULTS

There were 1.233 uninterrupted spontaneous breaths measured, and the overall mean Vt was 2.8±2.1 mL/kg. A lower Vt was found in infants who died (n=14) compared with survivors (n=16) (1.7±1.6 vs 3.7±2.1 mL/kg; p=0.008). Vt was lower in infants who died during admission or had CLD (n=20) compared with survivors without CLD (n=10) (2.0±1.7 vs 4.3±2.2 mL/kg; p=0.004). ROC analysis showed that Vt ≤2.2 mL/kg predicted mortality with 79% sensitivity and 81% specificity (AUC=0.77, p=0.013). Vt ≤3.4 mL/kg was a good predictor of death or CLD (AUC=0.80, p=0.008) with 85% sensitivity and 70% specificity.

CONCLUSION

Vt of spontaneous breaths measured immediately after birth is associated with mortality and CLD. Vt seems to be a reliable predictor but is not an independent predictor after adjustment for observed/expected lung to head ratio and liver position.

Validation of a Prediction Rule for Mortality in Congenital Diaphragmatic Hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly with a mortality of ∼27%. The Congenital Diaphragmatic Hernia Study Group (CDHSG) developed a simple postnatal clinical prediction rule to predict mortality in newborns with CDH. Our aim for this study is to externally validate the CDHSG rule in the European population and to improve its prediction of mortality by adding prenatal variables.

METHODS

We performed a European multicenter retrospective cohort study and included all newborns diagnosed with unilateral CDH who were born between 2008 and 2015. Newborns born from November 2011 onward were included for the external validation of the rule (n = 343). To improve the prediction rule, we included all patients born between 2008 and 2015 (n = 620) with prenatally diagnosed CDH and collected pre- and postnatal variables. We build a logistic regression model and performed bootstrap resampling and computed calibration plots.

RESULTS

With our validation data set, the CDHSG rule had an area under the curve of 79.0%, revealing a fair predictive performance. For the new prediction rule, prenatal herniation of the liver was added, and absent 5-minute Apgar score was taken out. The new prediction rule revealed good calibration, and with an area under the curve of 84.6%, it had good discriminative abilities.

CONCLUSIONS

In this study, we externally validated the CDHSG rule for the European population, which revealed fair predictive performance. The modified rule, with prenatal liver herniation as an additional variable, appears to further improve the model's ability to predict mortality in a population of patients with prenatally diagnosed CDH.

Prediction tools in congenital diaphragmatic hernia

Because congenital diaphragmatic hernia (CDH) is characterized by a spectrum of severity, risk stratification is an essential component of care. In both the prenatal and postnatal periods, accurate prediction of outcomes may inform clinical decision-making, care planning, and resource allocation. This review examines the history and utility of the most well-established risk prediction tools currently available, and provides recommendations for their optimal use in the management of CDH patients.

Calculating Observed-to-Expected Total Fetal Lung Volume in CDH Fetuses in Twin Gestation: Is There a Better Way?

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a potentially lethal birth defect, and identifying prenatal predictors of outcome is important. Observed-to-expected total fetal lung volume (o/e TFLV) has been shown to be a predictor of severity and useful in risk stratification but is variable due to different TFLV formulas.

OBJECTIVES

To calculate o/e TFLV for CDH patients part of a twin gestation using the unaffected sibling as an internal control and comparing these values to those calculated using published formulas for TFLV.

METHODS

Seven twin gestations with one fetus affected by CDH were identified between 2006 and 2017. The lung volume for each twin was calculated using magnetic resonance imaging (MRI), and o/e TFLV was calculated using the unaffected twin's TFLV. This percentage was then compared to the o/e TFLV calculated using published formulas.

RESULTS

Lung volumes in the unaffected twins were within normal ranges at the lower end of the spectrum. No single TFLV formula was found to correlate perfectly. Intraclass correlation coefficient estimate was most consistent for o/e TFLV calculated with the Meyers formula and supported by Bland-Altman plots.

CONCLUSIONS

O/e TFLV measured in CDH/non-CDH twin gestations using the unaffected sibling demonstrated agreement with o/e TFLV calculated using the Meyers formula. We urge the fetal community to standardize the method, use, and interpretation of fetal MRI in the prenatal evaluation of CDH.

Predictive value of gestational age at diagnosis for outcomes in prenatally diagnosed congenital diaphragmatic hernia

OBJECTIVE

To assess the value and accuracy of gestational age at diagnosis in predicting postnatal outcomes of prenatally diagnosed congenital diaphragmatic hernia (CDH).

STUDY DESIGN

The medical records of 158 prenatally diagnosed neonates with CDH from 2008 to 2018 were retrospectively reviewed. Data were analyzed using parametric and nonparametric tests, appropriately.

RESULTS

Gestational age at diagnosis predicted postnatal survival independently. Survival rate at discharge increased when gestational age at diagnosis increased (p < .001). Area under the receiver operator curve for survival for gestational age at diagnosis was 0.74, observed-to-expected lung to head ratio 0.74, and liver herniation 0.76. Patients diagnosed with CDH before 25 gestational weeks had a larger size of the diaphragmatic defect, more need for patch repair, longer duration of mechanical ventilation and hospital stay than those after 25 gestational weeks.

CONCLUSIONS

Gestational age at diagnosis is an independent predictor of CDH prognosis. It has a similar ability to predict survival compared to observed-to-expected lung to head ratio and liver herniation.

Imagiological methods for prediction of fetal pulmonary hypoplasia: a systematic review

OBJECTIVE

To compare the different imagiological methods for prediction of fetal pulmonary hypoplasia (PH) in general diseases and associated with preterm rupture of membranes (PROM), and congenital diaphragmatic hernia (CDH).

METHODS

According to PRISMA guidelines, all the literature on PH from 1988 to 2018 was reviewed. Twenty-nine articles were selected and analyzed for two- and three- dimensional-ultrasounds (2D and 3D-US) as predictors for the lethal outcome.

RESULTS

Overall, the results identify a general gap correlating prenatal pulmonary measurements and survival at birth; discrepant predictive values for the same imagiological methods are explained by the group heterogeneity in terms of diseases and degree of severity, with the 2D measurements being more affected than 3D; 2D and 3D-US present equally predictive values for groups with 0% of survival. Regarding PROM, results demonstrate comparable accuracies for similar survival rates suggesting a useful predictive value of 2D-US in outcome estimation; they also identify ultrasonographic methods as a more accurate prognostic factor than gestational age at rupture, latency or amniotic fluid index. In CDH, consistent with previous studies, our review shows magnetic resonance imaging as a better survival predictor followed by the 3D and 2D methods, while 2D-LHR was the more precise prognosticator correlating prenatal PH, survival at birth, and the need for neonatal respiratory support.

CONCLUSION

Ultrasonographic methods can be valuable predictors for lethal PH and should be validated for a broad set of diseases (e.g. PROM). For that, restricted studies for disease groups and correlating fetal PH with the needed of neonatal support, and survival at birth is critically recommended.

A comparative study of thoracoscopic and open surgery of congenital diaphragmatic hernia in neonates

Background

An increasing number of hospitals have carried out neonatal thoracoscopic assisted repair of congenital diaphragmatic hernia (CDH).

Methods

The 26 cases received thoracoscopic-assisted repair (observation group) and 44 cases open repair (control group). General anesthesia was performed with endotracheal intubation using a trachea cannula without cuff. The general preoperative data, intraoperative hemodynamic parameters, intraoperative surgical conditions, postoperative complications, postoperative recovery condition, postoperative survival rate and recurrence rate were recorded.

Results

The intraoperative mean arterial pressure and heart rate at each time point in observation group were more stable and effective than those in control group (all P <  0.001). The number of manual ventilation, SpO₂ < 90% and hypercapnia cases were significantly lower than those in control group (all P <  0.05). Intraoperative bleeding, incision length and operation duration were significantly lower in observation group compared with control group (all P <  0.001). No significant differences were seen between the two groups in postoperative complications including pulmonary infection, incision infection, pulmonary hypertension, hemorrhage, and scleredema (all P > 0.05). The duration of postoperative mechanical ventilation, antibiotic use and hospitalization in observation group was significantly shorter than those in control group (all P < 0.05). There was no significant difference in postoperative survival rate and recurrence rate between the two groups (both P > 0.05).

Conclusion

The intraoperative hemodynamic parameters of CDH repair under thoracoscopy were more stable, the duration of postoperative mechanical ventilation, antibiotic use and hospitalization were shortened, and the therapeutic effect was better.

Prediction of Mortality in Newborn Infants With Severe Congenital Diaphragmatic Hernia Using the Chest Radiographic Thoracic Area

OBJECTIVES

To evaluate whether the preoperative chest radiographic thoracic area in newborn infants with congenital diaphragmatic hernia was related to the length of mechanical ventilation and the total length of stay and whether chest radiographic thoracic area predicted survival to discharge from neonatal care.

DESIGN

Retrospective observational cohort study.

SETTING

Tertiary neonatal unit at King's College Hospital National Health Service Foundation Trust, London, United Kingdom.

PATIENTS

Newborn infants admitted with congenital diaphragmatic hernia at King's College Hospital in a 10-year period (2007-2017).

INTERVENTIONS

The chest radiographic thoracic area was assessed by free hand tracing of the perimeter of the thoracic area as outlined by the diaphragm and the rib cage and excluded the mediastinal structures and abdominal contents in the thorax and calculated using the Sectra PACS software (Sectra AB, Linköping, Sweden).

MEASUREMENTS AND MAIN RESULTS

Eighty-four infants with congenital diaphragmatic hernia (70 left-sided) were included with a median (interquartile range) gestation of 36 weeks (34-39 wk). Fifty-four (64%) survived to discharge from neonatal care. In the infants who survived the chest radiographic thoracic area was not related to the length of mechanical ventilation (r = 0.136; p = 0.328) or the total duration of stay (r = 0.095; p = 0.495). The median (interquartile range) chest radiographic thoracic area was higher in infants who survived (1,780 mm [1,446-2,148 mm]) compared with in the deceased infants (1,000 mm [663-1,449 mm]) after correcting for confounders (adjusted p = 0.01). Using receiver operator characteristics analysis, the chest radiographic thoracic area predicted survival to discharge from neonatal care with an area under the curve of 0.826. A chest radiographic thoracic area higher than 1,299 mm predicted survival to discharge with 85% sensitivity and 73% specificity.

CONCLUSIONS

The chest radiograph in infants with severe congenital diaphragmatic hernia can predict survival from neonatal care with high sensitivity and moderate specificity.

A multicentre study to predict neonatal survival according to lung-to-head ratio and liver herniation in fetuses with left congenital diaphragmatic hernia (CDH): Hidden mortality from the Latin American CDH Study Group Registry

OBJECTIVE

To evaluate natural history of fetuses congenital diaphragmatic hernia (CDH) prenatally diagnosed in countries where termination of pregnancy is not legally allowed and to predict neonatal survival according to lung area and liver herniation.

METHODS

Prospective study including antenatally diagnosed CDH cases managed expectantly during pregnancy in six tertiary Latin American centres. The contribution of the observed/expected lung-to-head ratio (O/E-LHR) and liver herniation in predicting neonatal survival was assessed.

RESULTS

From the total population of 380 CDH cases, 144 isolated fetuses were selected showing an overall survival rate of 31.9% (46/144). Survivors showed significantly higher O/E-LHR (56.5% vs 34.9%; P < .001), lower proportion of liver herniation (34.8% vs 80.6%, P < .001), and higher gestational age at birth (37.8 vs 36.2 weeks, P < 0.01) than nonsurvivors. Fetuses with an O/E-LHR less than 35% showed a 3.4% of survival; those with an O/E-LHR between 35% and 45% showed 28% of survival with liver up and 50% with liver down; those with an O/E-LHR greater than 45% showed 50% of survival rate with liver up and 76.9% with liver down.

CONCLUSIONS

Neonatal mortality in CDH is higher in Latin American countries. The category of lung hypoplasia should be classified according to the survival rates in our Latin American CDH registry.

Prenatal diagnosis and management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia is characterized by failed closure of the diaphragm, thereby allowing abdominal viscera to herniate into the thoracic cavity and subsequently interfering with normal lung development. At birth, pulmonary hypoplasia leads to respiratory insufficiency and persistent pulmonary hypertension (PHT), that is lethal in up to 32% of patients. In isolated cases, the outcome may be predicted prenatally by medical imaging and advanced genetic testing. In those fetuses with a predicted poor outcome, fetoscopic endoluminal tracheal occlusion may be offered. This procedure is currently being evaluated in a global randomized clinical trial (www.TOTALtrial.eu). We are currently investigating alternative strategies including transplacental sildenafil administration to reduce the occurrence of persistent PHT.

Congenital diaphragmatic hernia: a scientometric analysis of the global research activity and collaborative networks

Despite a growing interest to clinicians and scientists, there is no comprehensive study that examines the global research activity on congenital diaphragmatic hernia (CDH). A search strategy for the Web of Science™ database was designed to identify scientific CDH publications. Research output of countries, institutions, individual authors, and collaborative networks was analyzed. Semi-qualitative research measures including citation rate and h-index were assessed. Choropleth mapping and network diagrams were employed to visualize results. A total of 3669 publications were found, originating from 76 countries. The largest number was published by the USA (n = 1250), the UK (n = 279), and Canada (n = 215). The USA combined the highest number of cooperation articles (n = 152), followed by Belgium (n = 115) and the Netherlands (n = 93). The most productive collaborative networks were established between UK/Belgium (n = 53), Belgium/Spain (n = 47), and UK/Spain (n = 34). Canadian publications received the highest average citation rate (22.8), whereas the USA had the highest country-specific h-index (72). Eighty-five (2.3%) articles were published by international multicenter consortiums and national research networks. The most productive institutions and authors were based in North America and Europe. Over the past decades, CDH research has increasingly become multidisciplinary and numerous innovative therapeutic strategies were introduced. CDH-related research has constantly been progressing, involving today many disciplines with main research endeavors concentrating in a few high-income countries. Recent advances in prenatal interventions and regenerative medicine therapy hold the promise of improving CDH outcome in the 21st century. International collaborations and translational research should be strengthened to allow further evolution in this field.

The validity of the observed-to-expected lung-to-head ratio in congenital diaphragmatic hernia in an era of standardized neonatal treatment; a multicenter study

Objective

To assess the predictive value of observed‐to‐expected lung‐to‐head ratio (O/E LHR) for survival and chronic lung disease (CLD) in survivors of left‐sided congenital diaphragmatic hernia (CDH) in an era of standardized neonatal treatment, and to evaluate the predictive value of the O/E LHR trajectory for survival.

Methods

This retrospective cohort study was performed in two high‐volume CDH centers in the Netherlands in prenatally detected, isolated left‐sided CDH patients born between 2008 and 2014. O/E LHR and liver position were determined using 2D‐ultrasonography at three time points during gestation from 19 weeks onwards. Ultrasound measurements were performed on stored ultrasound data by one single experienced operator blinded to postnatal outcome.

Results

Of the 122 included cases, 77.9% survived of whom 38.9% developed CLD. A significant association was found between the first measured O/E LHR and survival and development of CLD in survivors. Prenatal liver position did not have additional predictive value. No significant association was found between the trajectory of the O/E LHR and survival.

Conclusion

In an era of standardized neonatal treatment for neonates with CDH, the first measured O/E LHR per patient significantly predicts survival and development of CLD in survivors in isolated left‐sided CDH infants. © 2017 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.