Hypoplasia In Congenital Diaphragmatic Hernia Research Articles

Overactivated Epithelial NF-κB Disrupts Lung Development in Congenital Diaphragmatic Hernia.

Abnormal lung development is the main cause of morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH), a common birth defect (1:2500) of largely unknown pathobiology. Recent studies discovered that inflammatory processes, and specifically NF-κB associated pathways are enriched in human and experimental CDH. However, the molecular signaling of NF-κB in abnormal CDH lung development and its potential as a therapeutic target requires further investigation. Using sections and hypoplastic lung explant cultures from the nitrofen rat model of CDH and human fetal CDH lungs, we demonstrate that NF-κB and its downstream transcriptional targets are hyperactive during abnormal lung formation in CDH. NF-κB activity was especially elevated in the airway epithelium of nitrofen and human CDH lungs at different developmental stages. Fetal rat lung explants had impaired pseudoglandular airway branching after exposure to nitrofen, together with increased phosphorylation and transcriptional activity of NF-κB. Dexamethasone, the broad and clinically applicable anti-inflammatory NF-κB antagonist, rescued lung branching and normalized NF-κB signaling in hypoplastic lung explants. Moreover, specific NF-κB inhibition with curcumenol similarly rescued ex vivo lung hypoplasia and restored NF-κB signaling. Lastly, we showed that prenatal intraperitoneal dexamethasone administration to pregnant rat dams carrying fetuses with hypoplastic lungs, significantly improves lung branching and normalizes NF-κB in vivo. Our results indicate that NF-κB is aberrantly activated in human and nitrofen CDH lungs. Anti-inflammatory treatment with dexamethasone and/ or specific NF-κB inhibition should be investigated further as a therapeutic avenue to target lung hypoplasia in CDH.

Proteomic Profiling of Hypoplastic Lungs Suggests an Underlying Inflammatory Response in the Pathogenesis of Abnormal Lung Development in Congenital Diaphragmatic Hernia.

The pathogenesis of lung hypoplasia in congenital diaphragmatic hernia (CDH), a common birth defect, is poorly understood. The diaphragmatic defect can be repaired surgically, but the abnormal lung development contributes to a high mortality in these patients. To understand the underlying pathobiology, we compared the proteomic profiles of fetal rat lungs at the alveolar stage (E21) that were either exposed to nitrofen in utero (CDH lungs, n=5) or exposed to vehicle only (non-CDH control lungs, n=5). Pathway analysis of proteomic datasets showed significant enrichment in inflammatory response proteins associated with cytokine signaling and Epstein Barr Virus in nitrofen CDH lungs. Among the 218 significantly altered proteins between CDH and non-CDH control lungs were Tenascin C, CREBBP, LYN, and STAT3. We showed that Tenascin C was decreased around the distal airway branches in nitrofen rat lungs and human CDH lungs, obtained from stillborn fetuses that did not receive pre- or postnatal treatment. In contrast, STAT3 was significantly increased in the airway epithelium of nitrofen lungs at E21. STAT3 inhibition after direct nitrofen exposure to fetal rat lung explants (E14.5) partially rescued the hypoplastic lung phenotype ex vivo by increasing peripheral lung budding. Moreover, we demonstrated that several STAT3-associated cytokines (IL-15, IL-9, andIL-2) are increased in fetal tracheal aspirates of CDH survivors compared with nonsurvivors after fetoscopic endoluminal tracheal occlusion. With our unbiased proteomics approach, we showed for the first time that downstream inflammatory processes are likely involved in the pathogenesis of abnormal lung development in CDH.

Fetal cardiac dimensions in congenital diaphragmatic hernia: relationship with gestational age and postnatal outcomes.

To serially assess fetal cardiac dimensions in congenital diaphragmatic hernia (CDH) and their relation to disease severity. Retrospective analysis of CDH cases and matched controls. Mitral (MVd) and tricuspid (TVd) valve diameters, left (LV) and right (RV) ventricular length and area, Z-scores, were serially assessed at 24-26, 30-32, and 35-37 weeks gestational age (GA). In CDH cases MVd, MVd Z-score, and LV area were significantly reduced at 24-26 and 35-37 weeks GA. TVd, TVd Z-score, and RV area were significantly reduced at 24-26 weeks. RV area Z-score increased with advancing GA. MVd and MVd Z-score were significantly lower at 24-26 weeks GA in CDH who had a combined outcome of death and/or ECMO. LV hypoplasia in CDH is characterized by reduced MVd from 24 weeks GA. MVd, and the ratio of mitral and tricuspid valve diameters at later gestations, may be potential predictors of disease severity.

Predicting lethal pulmonary hypoplasia in congenital diaphragmatic hernia (CDH): Institutional experience combined with CDH registry outcomes

BackgroundThe Severe Pulmonary Hypoplasia and Evaluation for Resuscitative Efforts (SPHERE) protocol was developed to attempt to identify CDH patients with likely lethal pulmonary hypoplasia. We present our experience with this protocol and utilize the CDH Registry to critically assess the protocol. MethodsSPHERE patients identified based on prenatal imaging (10/2009–1/2018) were offered ECMO if meeting postnatal physiologic criteria, while others received comfort measures. Within the CDH Registry, patients with suspected severe CDH were identified and separated into “passed” (lowest pCO2 ≤100) versus “failed” (lowest pCO2 >100) groups. ResultsOf 23 SPHERE patients, 57% (13/23) passed criteria for ECMO and survival was 46% (6/13) in that cohort. Of 4912 patients in the CDH Registry, 265 met criteria. There was no difference in survival rates between those that “passed” (122/227; 54%) versus “failed” (18/38; 47%). However, the latter had longer ECMO runs and more required ventilator/ECMO support at 30 days. Amongst survivors, the “failed” group had longer hospital stays and more frequently required tube feeds at discharge. ConclusionsThe SPHERE protocol did not predict mortality in the CDH Registry. However, our data suggest resource utilization is significant when unable to reach pCO2 ≤100 despite resuscitation. Morbidity remains high in this group. Level of evidenceLevel III Annotation of changesInstitutional Review Board Approval at University of Michigan (HUM00031524 and HUM00044010) Type of StudyRetrospective Review

Prenatal microRNA miR-200b Therapy Improves Nitrofen-induced Pulmonary Hypoplasia Associated With Congenital Diaphragmatic Hernia.

We aimed to evaluate the use of miR-200b as a prenatal transplacental therapy in the nitrofen rat model of abnormal lung development and congenital diaphragmatic hernia (CDH). Pulmonary hypoplasia (PH) and pulmonary hypertension determine mortality and morbidity in CDH babies. There is no safe medical prenatal treatment available. We previously discovered that higher miR-200b is associated with better survival in CDH babies. Here, we investigate the role of miR-200b in the nitrofen rat model of PH and CDH and evaluate its use as an in vivo prenatal therapy. We profiled miR-200b expression during nitrofen-induced PH using RT-qPCR and in situ hybridization in the nitrofen rat model of PH and CDH. The effects of nitrofen on downstream miR-200b targets were studied in bronchial lung epithelial cells using a SMAD luciferase assay, Western blotting and Immunohistochemistry. We evaluated miR-200b as a lung growth promoting therapy ex vivo and in vivo using lung explant culture and transplacental prenatal therapy in the nitrofen rat model. We show that late lung hypoplasia in CDH is associated with (compensatory) upregulation of miR-200b in less hypoplastic lungs. Increasing miR-200b abundance with mimics early after nitrofen treatment decreases SMAD-driven TGF-β signaling and rescues lung hypoplasia both in vitro and in vivo. Also, prenatal miR-200b therapy decreases the observed incidence of CDH. Our data indicate that miR-200b improves PH and decreases the incidence of CDH. Future studies will further exploit this newly discovered prenatal therapy for lung hypoplasia and CDH.

Prenatal non-surgical treatments for pulmonary hypoplasia in congenital diaphragmatic hernia

Prenatal non-surgical treatments for pulmonary hypoplasia in congenital diaphragmatic hernia

Fetoscopic Therapy for Severe Pulmonary Hypoplasia in Congenital Diaphragmatic Hernia: A First in Prenatal Regenerative Medicine at Mayo Clinic

ObjectiveTo introduce the prenatal regenerative medicine service at Mayo Clinic for fetal endoscopic tracheal occlusion (FETO) care for severe congenital diaphragmatic hernia (CDH). Patients and MethodsTwo cases of prenatal management of severe CDH with FETO between January and August 2017 are reported. Per protocol, FETO was offered for life-threatening severe CDH at between 26 and 29 weeks' gestation. Regenerative outcome end point was fetal lung growth. Gestational age at procedure and maternal and perinatal outcomes were additional monitored parameters. ResultsDiagnosis by ultrasonography of severe CDH was based on extremely reduced lung size (observed-to-expected lung area to head circumference ratio [o/e-LHR], eg, o/e-LHR of 20.3% for fetus 1 and 23.0% for fetus 2) along with greater than one-third of the liver herniated into the chest in both fetuses. Both patients underwent successful FETO at 28 weeks. At the time of intervention, no maternal or fetal complications were observed. Postintervention, fetal lung growth was observed in both fetuses, reaching an o/e-LHR of 62.7% at 36 weeks in fetus 1 and 52.4% at 32 weeks in fetus 2. The balloons were removed successfully at 35 weeks and 4 days by ultrasound-guided puncture in the first patient and at 32 weeks and 3 days by ex utero intrapartum therapy-to-airway procedure in the second patient. Postnatal management followed standard of care with patch CDH therapy. At discharge, one patient was breathing normally, whereas the other required minimal nasal cannula oxygen support. ConclusionThe successful launch of the first fetoscopic therapy for CDH at Mayo Clinic reveals its feasibility and safety, with early signs of benefit documented by fetal lung growth and reversal of severe pulmonary hypoplasia. Trial Registrationclinicaltrials.gov Identifier: G170062.

STATs in Lung Development: Distinct Early and Late Expression, Growth Modulation and Signaling Dysregulation in Congenital Diaphragmatic Hernia

Background: Congenital diaphragmatic hernia (CDH) is a life-threatening developmental anomaly, intrinsically combining severe pulmonary hypoplasia and hypertension. During development, signal transducers and activators of transcription (STAT) are utilized to elicit cell growth, differentiation, and survival. Methods: We used the nitrofen-induced CDH rat model. At selected gestational time points, lungs were divided into two experimental groups, i.e., control or CDH. We performed immunohistochemistry and western blotting analysis to investigate the developmental expression profile of the complete family of STATs (STAT1-6), plus specific STATs activation (p-STAT3, p-STAT6) and regulation by SOCS (SOCS3) in normal lungs against those of diseased lungs. The normal fetal lung explants were treated with piceatannol (STAT3 inhibitor) in vitro followed by morphometrical analysis. Results: Molecular profiling of STATs during the lung development revealed distinct early and late expression signatures. Experimental CDH altered the STATs expression, activation, and regulation in the fetal lungs. In particular, STAT3 and STAT6 were persistently over-expressed and early over-activated. Piceatannol treatment dose-dependently stimulated the fetal lung growth. Conclusion: These findings suggest that STATs play an important role during normal fetal lung development and CDH pathogenesis. Moreover, functionally targeting STAT signaling modulates fetal lung growth, which highlights that STAT3 and STAT6 signaling might be promising therapeutic targets in reducing or preventing pulmonary hypoplasia in CDH.

MicroRNA-200b regulates distal airway development by maintaining epithelial integrity

miR-200b plays a role in epithelial-to-mesenchymal transition (EMT) in cancer. We recently reported abnormal expression of miR-200b in the context of human pulmonary hypoplasia in congenital diaphragmatic hernia (CDH). Smaller lung size, a lower number of airway generations, and a thicker mesenchyme characterize pulmonary hypoplasia in CDH. The aim of this study was to define the role of miR-200b during lung development. Here we show that miR-200b−/− mice have abnormal lung function due to dysfunctional surfactant, increased fibroblast-like cells and thicker mesenchyme in between the alveolar walls. We profiled the lung transcriptome in miR-200b−/− mice, and, using Gene Ontology analysis, we determined that the most affected biological processes include cell cycle, apoptosis and protein transport. Our results demonstrate that miR-200b regulates distal airway development through maintaining an epithelial cell phenotype. The lung abnormalities observed in miR-200b−/− mice recapitulate lung hypoplasia in CDH.

胎児超音波検査による肺胸郭断面積比(LT比)の計測,及び先天性横隔膜ヘルニアにおける出生前診断,及び重症度の判定

胎児超音波検査による肺胸郭断面積比(LT比)の計測,及び先天性横隔膜ヘルニアにおける出生前診断,及び重症度の判定

Lipocalin 2 as a new biomarker for fetal lung hypoplasia in congenital diaphragmatic hernia

BackgroundCongenital diaphragmatic hernia (CDH) causes pulmonary hypoplasia, which are often fatal. We established a new biomarker for fetal lung hypoplasia in CDH. MethodsWe collected newborn lung tissue specimens at E21 from normal and nitrofen-induced CDH rats (administered 100mg orally at E9) and performed a microarray analysis and real-time PCR (RT-PCR). Sixty-three human amniotic fluid (AF) samples, including samples from isolated CDH cases (n=33) and Cesarean section (CS) cases without fetal complications (controls) (n=30), were obtained. All AF samples were obtained at the time of CS, which was performed after 35–38 gestational weeks, from April 2007 to January 2016. ResultsA microarray analysis and RT-PCR showed decreased gene expression levels of lipocalin 2 (LCN2) in the nitrofen-induced CDH lungs (p<0.05). We next examined the LCN2 levels in human AF samples using ELISA and the levels were significantly lower in the CDH cases than in controls (73.7ng/ml vs 163.8ng/ml; p<0.05). A significant positive correlation was observed between the amniotic LCN2 level and the observed/expected lung-to-head ratio (p<0.001). ConclusionsLCN2 may be a potentially useful biomarker for lung hypoplasia in a rat and human CDH.

High-Resolution (1)H NMR Spectroscopy Discriminates Amniotic Fluid of Fetuses with Congenital Diaphragmatic Hernia from Healthy Controls.

Lung hypoplasia in congenital diaphragmatic hernia (CDH) is a life-threatening birth defect. Severe cases can be offered tracheal occlusion to boost prenatal lung development, although defining those to benefit remains challenging. Metabonomics of (1)H NMR spectra collected from amniotic fluid (AF) can identify general changes in diseased versus healthy fetuses. AF embodies lung secretions and hence might contain pulmonary next to general markers of disease in CDH fetuses. AF from 81 healthy and 22 CDH fetuses was collected. NMR spectroscopy was performed at 400 MHz to compare AF from fetuses with CDH against controls. Several advanced feature extraction methods based on statistical tests that explore spectral variability, similarity, and dissimilarity were applied and compared. This resulted in the identification of 30 spectral regions, which accounted for 80% variability between CDH and controls. Combination with automated classification discriminates AF from CDH versus healthy fetuses with up to 92% accuracy. Within the identified spectral regions, isoleucine, leucine, valine, pyruvate, GABA, glutamate, glutamine, citrate, creatine, creatinine, taurine, and glucose were the most concentrated metabolites. As the metabolite pattern of AF changes with fetal development, we have excluded metabolites with a high age-related variability and repeated the analysis with 12 spectral regions, which has resulted in similar classification accuracy. From this analysis, it was possible to distinguish between AF from CDH fetuses versus healthy controls independent of gestational age.

Medical interventions to reverse pulmonary hypoplasia in the animal model of congenital diaphragmatic hernia: A systematic review.

We aimed to systematically review all published pre-clinical research on prenatal medical treatment of pulmonary hypoplasia in congenital diaphragmatic hernia (CDH). Background The neonatal mortality due to isolated CDH remains high. Whether fetal endoscopic tracheal occlusion (FETO) reduces mortality is still to be demonstrated. Therefore more potent preferentially medical therapy would be welcomed. Methods We searched MEDLINE (Pubmed), Embase and the Web of Science including all studies from the earliest date (1951) to December 2013. Article quality was assessed using the modified CAMRADES checklist. Inclusion criteria were those animal studies addressing prenatal medical interventions and principal variables were confirmation of a diaphragmatic defect, lung to body weight ratio (LBWR), formal airway morphometry or DNA/protein content. Results In total 983 articles were identified. Following abstract review, 96 articles were assessed by two authors in agreement with a third for eligibility. Of these, 43 were included in the final analysis. The median number of study quality checklist items (maximum 10) scored was 4 (IQ range: 2-5). Thirty (69.8%) of studies were in the nitrofen rat. The majority were treated with vitamins or glucocorticoids. Single studies reported some improvement in lung morphology with alternative therapies. It was impossible to identify a pattern in animal model selection or creation, mode, time point or duration of treatment and readouts. Only one study reported a sample size calculation. Conclusion Comparison in pre-clinical studies in CDH is challenging due to methodological variation. Agreed standardized methods need to be applied in future investigation of new medical therapies.

Defective parasympathetic innervation is associated with airway branching abnormalities in experimental CDH.

Developmental mechanisms leading to lung hypoplasia in congenital diaphragmatic hernia (CDH) remain poorly defined. Pulmonary innervation is defective in the human disease and in the rodent models of CDH. We hypothesize that defective parasympathetic innervation may contribute to airway branching abnormalities and, therefore, lung hypoplasia, during lung development in CDH. The murine nitrofen model of CDH was utilized to study the effect of the cholinergic agonist carbachol on embryonic day 11.5 (E11.5) lung explant cultures. Airway branching and contractions were quantified. In a subset of experiments, verapamil was added to inhibit airway contractions. Sox9 immunostaining and 5-bromo-2-deoxyuridine incorporation were used to identify and quantify the number and proliferation of distal airway epithelial progenitor cells. Intra-amniotic injections were used to determine the in vivo effect of carbachol. Airway branching and airway contractions were significantly decreased in nitrofen-treated lungs compared with controls. Carbachol resulted in increased airway contractions and branching in nitrofen-treated lungs. Nitrofen-treated lungs exhibited an increased number of proliferating Sox9-positive distal epithelial progenitor cells, which were decreased and normalized by treatment with carbachol. Verapamil inhibited the carbachol-induced airway contractions in nitrofen-treated lungs but had no effect on the carbachol-induced increase in airway branching, suggesting a direct carbachol effect independent of airway contractions. In vivo treatment of nitrofen-treated embryos via amniotic injection of carbachol at E10.5 resulted in modest increases in lung size and branching at E17.5. These results suggest that defective parasympathetic innervation may contribute to airway branching abnormalities in CDH.

Lower NPAS3 expression during the later stages of abnormal lung development in rat congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is characterized by a developmental defect in the diaphragm, pulmonary hypoplasia and pulmonary hypertension. NPAS3 is a PAS domain transcription factor regulating Drosophila tracheogenesis. NPAS3 null mice develop pulmonary hypoplasia in utero and die after birth due to respiratory failure. We aimed to evaluate NPAS3 expression during normal and abnormal lung development due to CDH. CDH was induced by administering 100mg/ml nitrofen to time-pregnant dams on embryonic day (E) 9 of gestation. Lungs were isolated on E15, E18 and E21 and NPAS3 localization was determined by immunohistochemistry and quantified using Western blotting. We found that only E21 hypoplastic CDH lungs have reduced expression of NPAS3 in the terminal saccules. Western blotting confirmed the down-regulation of NPAS3 protein in the nitrofen-induced hypoplastic lungs. We demonstrate for the first time that nitrofen-induced hypoplastic CDH lungs have reduced NPAS3 expression in the terminal saccules during the later stages of abnormal lung development. Our findings suggest that NPAS3 is associated with pulmonary hypoplasia in CDH.

Immunohistochemical changes in the lungs from fetuses and newborn infants at 20- 40 weeks' gestation with false left-sided congenital diaphragmatic hernia

to study changes in the expression of growth factors in the lungs from fetuses and newborn infants at 20-40 weeks' gestation with false left-sided congenital diaphragmatic hernia (CDH). Lung fragments obtained at autopsies were examined using immunohistochemically stained paraffin sections. The expression indices of insulin-like growth factor-1 (IGF-1), platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and transforming grow factor-β (TGF-β) in the fetal lung sections were compared with the results of survey and elective staining techniques, the morphometric data of digitized lung sections, and the indicators obtained in the comparison group. Morphofunctional changes in the connective tissue, pulmonary vessels, and bronchial and alveolar epithelium at 20-24, 25-27, and 28-40 weeks' gestation were characterized, partly explaining the development of bilateral pulmonary hypoplasia in CDH. There was evidence for the involvement of PDGF, IGF-1, and EGF in primary pulmonary hypoplasia. PDGF deficiency plays a certain role in secondary pulmonary hypoplasia. The findings can be used in researches and in the practical work of pathologists and forensic medical experts.

Prenatal administration of neuropeptide bombesin promotes lung development in a rat model of nitrofen-induced congenital diaphragmatic hernia

Background/purposeFetal medical treatment to improve lung hypoplasia in congenital diaphragmatic hernia (CDH) has yet to be established. The neuropeptide bombesin (BBS) might play an important role in lung development. The present study aims to determine whether prenatally administered BBS could be useful to promote fetal lung development in a rat model of nitrofen-induced CDH. MethodsPregnant rats were administered with nitrofen (100mg) on gestation day 9.5 (E9.5). BBS (50mg/kg/day) was then daily infused intraperitoneally from E14, and fetal lungs were harvested on E21. The expression of PCNA was assessed by both immunohistochemical staining and RT-PCR to determine the amount of cell proliferation. Lung maturity was assessed as the expression of TTF-1, a marker of alveolar epithelial cell type II. ResultsThe lung-body-weight ratio was significantly increased in CDH/BBS(+) compared with CDH/BBS(−) (p<0.05). The number of cells stained positive for PCNA and TTF-1 was significantly decreased in CDH/BBS(+) compared with CDH/BBS(−) (p<0.01). The TTF-1 mRNA expression levels were significantly decreased in CDH/BBS(+) compared with CDH/BBS(−) (p<0.05). ConclusionsPrenatally administered BBS promotes lung development in a rat model of nitrofen-induced CDH. Neuropeptide BBS could help to rescue lung hypoplasia in fetal CDH.

BMP4 and LGL1 are Down Regulated in an Ovine Model of Congenital Diaphragmatic Hernia.

Background/Purpose: The molecular pathophysiology of lung hypoplasia in congenital diaphragmatic hernia (CDH) remains poorly understood. The Wnt signaling pathway and downstream targets, such as bone morphogenetic proteins (BMP) 4 and other factors such as late gestation lung protein 1 (LGL1), are essential to normal lung development. Nitrofen-induced hypoplastic CDH rodent lungs demonstrate down regulation of the Wnt pathway including BMP4 and reduced LGL1 expression. The aim of the current study was to examine the molecular pathophysiology associated with a surgically induced CDH in an ovine model.Methods: Left thoracotomy was performed at 80 days in 14 fetal sheep; CDH was created in seven experimental animals. Lungs were harvested at 136 days (term = 145 days). Lung weight (LW) and mean terminal bronchiole density (MTBD) were measured to determine the degree of pulmonary hypoplasia. Quantitative real time PCR was undertaken to analyze Wnt2, Wnt7b, BMP4, and LGL1 mRNA expression.Results: Total LW was decreased while MTBD was increased in the CDH group (p < 0.05), confirming pulmonary hypoplasia. BMP4 and LGL1 mRNA was significantly reduced in CDH lungs (p < 0.05). Wnt2 mRNA was decreased, although not significantly (p < 0.06).Conclusion: For the first time, down regulation of BMP4 and LGL1 are reported in an ovine CDH model. In contrast to other animal models, these changes are persistent to near term. These findings suggest that mechanical compression from herniated viscera may play a more important role in causing pulmonary hypoplasia in CDH, rather than a primary defect in lung organogenesis.

Assessment of pulmonary vascular reactivity to oxygen using fractional moving blood volume in fetuses with normal lung development and pulmonary hypoplasia in congenital diaphragmatic hernia.

The objective of this study is to evaluate whether assessment pulmonary vascular reactivity in response to maternal hyperoxygenation using fractional moving blood volume (FMBV) is associated with lesser variability between individual measurements than what is observed with direct Doppler measurements. Forty-five measurements were performed in 15 singleton fetuses with normal lung development at three time points in the latter half of pregnancy (range: 25.9-36.7 weeks). We further evaluated five fetuses with severe congenital diaphragmatic hernia. Lung perfusion was assessed using power Doppler ultrasound, and images were stored for offline FMBV calculation, both at base line and during oxygen administration (9 L/min for 10 min). The proportionate difference between both measurements is further referred to as deltaFMBV. Overall, 91% of images were of sufficient quality for further analysis. There was no correlation between pulmonary reactivity to oxygen (deltaFMBV) and gestational age in controls (12.9 ± 32.1%). Moreover, deltaFMBV showed large variability between subjects, as well as within the same fetus throughout gestation. We observed good intraobserver (0.88; 0.84) and interobserver (0.88; 0.77) reproducibility for both controls and congenital diaphragmatic hernia, respectively (intraclass correlation coefficients). Despite being a reproducible method to study the lung vasculature, the large variability of FMBV following hyperoxygenation limits its clinical translation.

FETO effects on tracheal diameter

In order to ameliorate pulmonary hypoplasia in congenital diaphragmatic hernia (CDH), an approach has been taken using fetal endoscopic tracheal occlusion (FETO). The rationale is that a balloon prevents liquid from escaping from the lungs in utero, resulting in increased airway pressure, increased lung volumes, and maturation of pulmonary vessels. A side effect of FETO is tracheomegaly. The question of whether tracheomegaly truly is more common in infants treated with FETO, compared with children without such treatment, was addressed by Zani et al in this issue of The Journal.