The developmental biology of genetic Notch disorders.

Notch signaling regulates a vast array of crucial developmental processes. It is therefore not surprising that mutations in genes encoding Notch receptors or ligands lead to a variety of congenital disorders in humans. For example, loss of function of Notch results in Adams-Oliver syndrome, Alagille syndrome, spondylocostal dysostosis and congenital heart disorders, while Notch gain of function results in Hajdu-Cheney syndrome, serpentine fibula polycystic kidney syndrome, infantile myofibromatosis and lateral meningocele syndrome. Furthermore, structure-abrogating mutations in NOTCH3 result in CADASIL. Here, we discuss these human congenital disorders in the context of known roles for Notch signaling during development. Drawing on recent analyses by the exome aggregation consortium (EXAC) and on recent studies of Notch signaling in model organisms, we further highlight additional Notch receptors or ligands that are likely to be involved in human genetic diseases.

Kif7 is required for the patterning and differentiation of the diaphragm in a model of syndromic congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a common birth defect that results in a high degree of neonatal morbidity and mortality, but its pathological mechanisms are largely unknown. Therefore, we performed a forward genetic screen in mice to identify unique genes, models, and mechanisms of abnormal diaphragm development. We identified a mutant allele of kinesin family member 7 (Kif7), the disorganized diaphragm (dd). Embryos homozygous for the dd allele possess communicating diaphragmatic hernias, central tendon patterning defects, and increased cell proliferation with diaphragmatic tissue hyperplasia. Because the patterning of the central tendon is undescribed, we analyzed the expression of genes regulating tendonogenesis in dd/dd mutant embryos, and we determined that retinoic acid (RA) signaling was misregulautted. To further investigate the role of Kif7 and RA signaling in the development of the embryonic diaphragm, we established primary mesenchymal cultures of WT embryonic day 13.5 diaphragmatic cells. We determined that RA signaling is necessary for the expression of tendon markers as well as the expression of other CDH-associated genes. Knockdown of Kif7, and retinoic acid receptors alpha (Rara), beta (Rarb), and gamma (Rarg) indicated that RA signaling is dependent on these genes to promote tendonogenesis within the embryonic diaphragm. Taken together, our results provide evidence for a model in which inhibition of RA receptor signaling promotes CDH pathogenesis through a complex gene network.

Case Report: Fetal Bilateral Diaphragmatic Agenesis, Ectopic Liver and Abnormal Pancreas.

Congenital bilateral diaphragm agenesis is a very rare condition. We describe limited (abdomen only) autopsy findings of a case of bilateral diaphragm agenesis in a 27-week male fetus with unusual findings of fibrosis of the pancreatic head and ectopic liver nodules in a mass at the upper abdomen that may represent a possible diaphragm anlage. We have correlated our observations with data from experimental and embryological studies to suggest possible mechanisms for the malformations that were present and their implications for our understanding of pancreas, liver and diaphragm development in the human fetus.

Repetitive MR measurements of lung volume in fetuses with congenital diaphragmatic hernia: individual development of pulmonary hypoplasia during pregnancy and calculation of weekly lung growth rates.

OBJECTIVE: To investigate individual changes in fetal lung volume (FLV) in fetuses with isolated congenital diaphragmatic hernia (CDH) and to calculate weekly growth rates of the FLV using serial MR examinations during pregnancy. METHODS: MR-FLV was measured in 89 fetuses with CDH. All fetuses received two MRIs. A mean weekly growth rate of the FLV was determined for each fetus and compared with the growth rate of healthy fetuses. RESULTS: Mean observed-to-expected MR-FLV (o/e MR-FLV) measured at the first MRI was 33.3 ± 12.2% and 29.5 ± 10.9% at the second MRI. In 61% of all fetuses (54/89) the o/e MR-FLV decreased during pregnancy, 26% (23/89) showed an increase in the o/e MR-FLV and 13 % (12/89) had stable values. First and last o/e MR-FLV values were significantly associated with mortality and neonatal extracorporeal membrane oxygenation (ECMO) requirement with a higher prognostic accuracy of MR-FLV measurements near delivery. Patients with CDH had lower weekly lung growth rates than healthy fetuses. There was a significant difference in the mean weekly growth rate between survivors and non-survivors and patients with and without ECMO requirement. CONCLUSION: Individual development of FLV in patients with CDH during pregnancy is extremely variable. Follow-up MR-FLV measurements are advisable before deciding upon pre- and postnatal therapeutic options. KEY POINTS: • Lung development in congenital diaphragmatic hernia (CDH) during pregnancy is extremely variable. • MRI demonstrates that lung growth rate is reduced in fetuses with CDH. • The final observed-to-expected fetal lung volume provides the best prognostic information. • Follow-up measurements are advisable before deciding upon therapeutic options.

Disruption of THY-1 signaling in alveolar lipofibroblasts in experimentally induced congenital diaphragmatic hernia.

PURPOSE: Pulmonary hypoplasia (PH), characterized by alveolar immaturity, remains the main cause of neonatal mortality and long-term morbidity in infants with congenital diaphragmatic hernia (CDH). Lipid-containing interstitial fibroblasts (LIFs) are critically important for normal alveolar development. Thymocyte antigen 1 (Thy-1) is a highly expressed cell-surface protein in this specific subset of lung fibroblasts, which plays a key role in fetal alveolarization by coordinating the differentiation and lipid homeostasis of alveolar LIFs. Thy-1 increases the lipid content of LIFs by upregulation of adipocyte differentiation-related protein (ADRP), a lipogenic molecular marker characterizing pulmonary LIFs. Thy-1 (-/-) mice further show impaired alveolar development with reduced proliferation of pulmonary LIFs, resulting in a PH-similar phenotype. We hypothesized that pulmonary Thy-1 signaling is disrupted in experimentally induced CDH, which may has an adverse effect on the lipid content of alveolar LIFs. METHODS: Timed-pregnant Sprague-Dawley rats were treated with either 100 mg nitrofen or vehicle on embryonic day 9.5 (E9.5). Fetuses were killed on E21.5, and lungs were divided into controls (n = 14) and CDH-associated PH (n = 14). Pulmonary gene expression levels of Thy-1 and ADRP were assessed by quantitative real-time PCR. ADRP immunohistochemistry and oil-red-O staining were used to localize alveolar LIF expression and lipid droplets. Immunofluorescence double staining for Thy-1 and oil-red-O was performed to evaluate Thy-1 expression and lipid content in alveolar LIFs. RESULTS: Radial alveolar count was significantly reduced in CDH-associated PH with significant downregulation of pulmonary Thy-1 and ADRP mRNA expression compared to controls. ADRP immunoreactivity and lipid droplets were markedly diminished in alveolar interstitial cells, which coincided with decreased alveolar LIF expression in CDH-associated PH compared to controls. Confocal laser scanning microscopy confirmed markedly decreased Thy-1 expression and lipid content in alveolar LIFs of CDH-associated PH compared to controls. CONCLUSION: Our study provides strong evidence that disruption of pulmonary Thy-1 signaling results in reduced lipid droplets in alveolar LIFs and may thus contribute to PH in the nitrofen-induced CDH model. Treatment modalities aimed at increasing lipid content in alveolar LIFs may therefore have a therapeutic potential in attenuating CDH-associated PH.

Prenatal administration of retinoic acid increases the trophoblastic insulin-like growth factor 2 protein expression in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: The high mortality rate in congenital diaphragmatic hernia (CDH) is attributed to pulmonary hypoplasia (PH). Insulin-like growth factor 2 (IGF2) is an important regulator of fetal growth. The highest levels of IGF2 expression are found in the placenta, which are negatively regulated by decidual retinoid acid receptor alpha (RARα). It has been demonstrated that prenatal administration of retinoic acid (RA) suppresses decidual RARα expression. Previous studies have further shown that prenatal administration of RA can reverse PH in nitrofen-induced CDH model. In IGF2 knockout animals, low levels of IGF2 are associated with decreased placental growth and PH. We therefore hypothesized that nitrofen decreases trophoblastic IGF2 expression and prenatal administration of RA increases it through decidual RARα in the nitrofen-induced CDH model. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). RA was given intraperitoneally on D18, D19 and D20. Fetuses were harvested on D21 and divided into three groups: control, CDH and nitrofen+RA. Immunohistochemistry was performed to evaluate decidual RARα and trophoblastic IGF2 expression. Protein levels of IGF2 in serum, intra-amniotic fluid and left lungs were measured by enzyme-linked immunosorbent assay. RESULTS: Significant growth retardation of placenta and left lungs was observed in the CDH group compared to control and nitrofen+RA group. Markedly increased decidual RARα and decreased IGF2 immunoreactivity were found in the CDH group compared to control and nitrofen+RA group. Significantly decreased IGF2 protein levels were detected in serum, intra-amniotic fluid and left lungs in the CDH group compared to control and nitrofen+RA group. CONCLUSION: Our findings suggest that nitrofen may disturb trophoblastic IGF2 expression through decidual RARα resulting in retarded placental growth and PH in the nitrofen-induced CDH. Prenatal administration of RA may promote lung and placental growth by increasing trophoblastic IGF2 expression.

Notch inhibition by the ligand DELTA-LIKE 3 defines the mechanism of abnormal vertebral segmentation in spondylocostal dysostosis.

Mutations in the DELTA-LIKE 3 (DLL3) gene cause the congenital abnormal vertebral segmentation syndrome, spondylocostal dysostosis (SCD). DLL3 is a divergent member of the DSL family of Notch ligands that does not activate signalling in adjacent cells, but instead inhibits signalling when expressed in the same cell as the Notch receptor. Targeted deletion of Dll3 in the mouse causes a developmental defect in somite segmentation, and consequently vertebral formation is severely disrupted, closely resembling human SCD. In contrast to the canonical Notch signalling pathway, very little is known about the mechanism of cis-inhibition by DSL ligands. Here, we report that Dll3 is not presented on the surface of presomitic mesoderm (PSM) cells in vivo, but instead interacts with Notch1 in the late endocytic compartment. This suggests for the first time a mechanism for Dll3-mediated cis-inhibition of Notch signalling, with Dll3 targeting newly synthesized Notch1 for lysosomal degradation prior to post-translational processing and cell surface presentation of the receptor. An inhibitory role for Dll3 in vivo is further supported by the juxtaposition of Dll3 protein and Notch1 signalling in the PSM. Defining a mechanism for cis-inhibition of Notch signalling by Dll3 not only contributes greatly to our understanding of this ligand's function during the formation of the vertebral column, but also provides a paradigm for understanding how other ligands of Notch cis-inhibit signalling.

Liver-to-thoracic volume ratio: use at MR imaging to predict postnatal survival in fetuses with isolated congenital diaphragmatic hernia with or without prenatal tracheal occlusion.

OBJECTIVE: To evaluate the relationship of the liver-to-thoracic volume ratio (LiTR) by MRI with postnatal survival in foetuses with isolated congenital diaphragmatic hernia (CDH). METHODS: In 30 conservatively managed CDH foetuses and in 31 who underwent fetoscopic endoluminal tracheal occlusion (FETO), logistic regression analysis was used to investigate the effect on postnatal survival of the observed-to-expected (O/E) ratio of total foetal lung volume (TFLV), LiTR, gestational age at delivery, CDH side, intrathoracic position of the liver and, for those who underwent FETO, gestational age at FETO and occlusion period. For 19 foetuses undergoing FETO, a post-FETO MRI was available. The proportionate increase in O/E ratio of TFLV at 3-8 weeks after FETO was compared with the pre-FETO value and correlated with pre-FETO LiTR using linear regression analysis. RESULTS: For conservatively managed foetuses, only LiTR provided a significant prediction of postnatal survival. For foetuses undergoing FETO, LiTR and gestational age at delivery provided a significant independent prediction of postnatal survival. There was a significant inverse association between lung response and pre-FETO LiTR. CONCLUSION: In foetuses with CDH with/without FETO treatment, the LiTR is predictive of postnatal survival at discharge. In foetuses treated with FETO, LiTR is predictive of post-FETO lung response. KEY POINTS: • Congenital diaphragmatic hernia is usually managed conservatively before surgery soon after delivery • Fetoscopic endoluminal tracheal occlusion (FETO) has been introduced for severely affected foetuses • In conservatively managed CDH, the liver-to-thoracic volume ratio (LiTR) predicted postnatal survival best. • In severe CDH with prenatal FETO, LiTR also helped predict postnatal survival. • LiTR should be integrated into the prenatal decision-making for foetuses with CDH.

Predictors of neonatal morbidity in fetuses with severe isolated congenital diaphragmatic hernia undergoing fetoscopic tracheal occlusion.

OBJECTIVES: To investigate neonatal morbidity in fetuses with severe congenital diaphragmatic hernia (CDH) treated with fetoscopic endoluminal tracheal occlusion (FETO) and compare it with historical controls with less severe forms of CDH that were managed expectantly. METHODS: This was a prospective, multicenter study on neonatal outcomes and prenatal predictors in 90 FETO survivors (78 left-sided, 12 right) and 41 controls from the antenatal CDH registry with either severe or moderate hypoplasia who were managed expectantly. We also investigated early neonatal morbidity indicators, including the need for patch repair, duration of mechanical ventilation and supplemental oxygen, age at full enteral feeding and incidence of pulmonary hypertension. RESULTS: Gestational age at delivery was predictive of duration of assisted ventilation (P = 0.046), days on supplemental oxygen (P = 0.019) and age at full enteral feeding (P = 0.020). When delivery took place after 34 weeks' gestation, neonatal morbidity of FETO cases was comparable with that of expectantly managed cases with moderate hypoplasia. CONCLUSIONS: Fetal intervention for severe CDH is associated with neonatal morbidity that is comparable with that of an expectantly managed group with less severe disease.

Quantitative lung index, contralateral lung area, or lung-to-head ratio to predict the neonatal outcome in isolated congenital diaphragmatic hernia?

OBJECTIVES: To estimate the accuracy of the quantitative lung index and contralateral lung area for prediction of the neonatal outcome in isolated congenital diaphragmatic hernia in comparison to other available prediction models. METHODS: Between January 2004 and December 2010, 108 fetuses with isolated (82 left-sided and 26 right-sided) congenital diaphragmatic hernia were prospectively evaluated. The quantitative lung index and observed-to-expected contralateral lung area were measured and compared to the neonatal survival rate and severe postnatal pulmonary arterial hypertension, along with the lung-to-head ratio, observed-to-expected lung-to-head ratio, and observed-to-expected total lung volume. RESULTS: Overall neonatal mortality was 64.8% (70 of 108). Severe pulmonary arterial hypertension was diagnosed in 68 (63.0%) of the cases, which was associated with neonatal death (P < .001). Both the quantitative lung index and observed-to-expected contralateral lung area were significantly associated with neonatal survival and pulmonary arterial hypertension (P < .001), with accuracy to predict survival of 70.9% and 70.0%, respectively, and accuracy to predict hypertension of 78.7% and 72.0%; however, they were both less accurate than the observed-to-expected total lung volume (83.3% and 86.1%; P < .01). The lung-to-head ratio (73.1% and 78.7%) and observed-to-expected lung-to-head ratio (75.9% and 72.2%; P > .05) had similar accuracy as the quantitative lung index and observed-to-expected contralateral lung area. CONCLUSIONS: The observed-to-expected total lung volume is the most accurate predictor of the neonatal outcome in cases of isolated congenital diaphragmatic hernia. Both the quantitative lung index and observed-to-expected contralateral lung area, albeit reasonably accurate, do not produce the same level of accuracy and render similar results as the lung-to-head ratio and observed-to-expected lung-to-head ratio.

Preferential streaming of the ductus venosus toward the right atrium is associated with a worse outcome despite a higher rate of invasive procedures in human fetuses with left diaphragmatic hernia.

PURPOSE: Preferential streaming of the ductus venosus (DV) toward the right atrium has been observed in fetuses with left diaphragmatic hernia (LDH). The purpose of this retrospective study was to compare survival rates to discharge between a group with preferential streaming of the DV toward the right heart and a group in which this abnormal flow pattern was not present. MATERIALS AND METHODS: We retrospectively searched our patient records for fetuses with LDH in whom liver position, DV streaming and postnatal outcome information was available. 55 cases were found and divided into two groups: Group I fetuses exhibited abnormal DV streaming toward the right side of the heart; group II fetuses did not. Various prognostic and outcome parameters were compared. RESULTS: 62 % of group I fetuses and 88 % of group II fetuses survived to discharge (p = 0.032). Fetoscopic tracheal balloon occlusion (FETO) was performed in 66 % of group I fetuses and 23 % of group II fetuses (p = 0.003). Postnatal ECMO therapy was performed in 55 % of group I fetuses and 23 % of group II infants (p = 0.025). Moderate to severe chronic lung disease in survivors was observed in 56 % of the survivors of group I and 9 % of the survivors of group II (p = 0.002). CONCLUSION: Preferential streaming of the DV toward the right heart in human fetuses with left-sided diaphragmatic hernia was associated with a poorer postnatal outcome despite a higher rate of invasive pre- and postnatal procedures compared to fetuses without this flow abnormality. Specifically, abnormal DV streaming was found to be an independent predictor for FETO.

Imaging of the diaphragm: anatomy and function.

The diaphragm is the primary muscle of ventilation. Dysfunction of the diaphragm is an underappreciated cause of respiratory difficulties and may be due to a wide variety of entities, including surgery, trauma, tumor, and infection. Diaphragmatic disease usually manifests as elevation at chest radiography. Functional imaging with fluoroscopy (or ultrasonography or magnetic resonance imaging) is a simple and effective method of diagnosing diaphragmatic dysfunction, which can be classified as paralysis, weakness, or eventration. Diaphragmatic paralysis is indicated by absence of orthograde excursion on quiet and deep breathing, with paradoxical motion on sniffing. Diaphragmatic weakness is indicated by reduced or delayed orthograde excursion on deep breathing, with or without paradoxical motion on sniffing. Eventration is congenital thinning of a segment of diaphragmatic muscle and manifests as focal weakness. Treatment of diaphragmatic paralysis depends on the cause of the dysfunction and the severity of the symptoms. Treatment options include plication and phrenic nerve stimulation. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115127/-/DC1.

Protective effect of fetal pulmonary sequestration in two cases of postnatal manifestation of congenital diaphragmatic hernia.

We describe two cases of postnatally diagnosed congenital diaphragmatic hernia (CDH) combined with pulmonary sequestration, both of which were diagnosed as isolated pulmonary sequestration on prenatal ultrasound. In these cases, prenatal ultrasonography demonstrated only a hyperechoic mass on the left lower lung and the diaphragm seemed intact. In each case both lungs showed otherwise normal development throughout pregnancy. Pulmonary sequestration may serve as a 'protector', preventing herniation of abdominal contents into the thoracic cavity. The co-occurrence of CDH may be obscured by a lung mass, especially on the left lower lung, and therefore it is necessary to deliver these infants at a tertiary center and parents should be counseled about the possibility of postnatal CDH.

A randomized controlled trial of fetal endoscopic tracheal occlusion versus postnatal management of severe isolated congenital diaphragmatic hernia.

OBJECTIVE: Severe pulmonary hypoplasia and pulmonary arterial hypertension are associated with reduced survival in congenital diaphragmatic hernia (CDH). We aimed to determine whether fetal endoscopic tracheal occlusion (FETO) improves survival in cases of severe isolated CDH. METHODS: Between May 2008 and July 2010, patients whose fetuses had severe isolated CDH (lung-to-head ratio < 1.0, liver herniation into the thoracic cavity and no other detectable anomalies) were assigned randomly to FETO or to no fetal intervention (controls). FETO was performed under maternal epidural anesthesia supplemented with fetal intramuscular anesthesia. Tracheal balloon placement was achieved with ultrasound guidance and fetoscopy between 26 and 30 weeks of gestation. All cases that underwent FETO were delivered by the EXIT procedure. Postnatal therapy was the same for both treated fetuses and controls. The primary outcome was survival to 6 months of age. Other maternal and neonatal outcomes were also evaluated. RESULTS: Twenty patients were enrolled randomly to FETO and 21 patients to standard postnatal management. The mean gestational age at randomization was similar in both groups (P = 0.83). Delivery occurred at 35.6 ± 2.4 weeks in the FETO group and at 37.4 ± 1.9 weeks in the controls (P < 0.01). In the intention-to-treat analysis, 10/20 (50.0%) infants in the FETO group survived, while 1/21 (4.8%) controls survived (relative risk (RR), 10.5 (95% CI, 1.5-74.7), P < 0.01). In the received-treatment analysis, 10/19 (52.6%) infants in the FETO group and 1/19 (5.3%) controls survived (RR, 10.0 (95% CI, 1.4-70.6) P < 0.01). CONCLUSION: FETO improves neonatal survival in cases with isolated severe CDH.

Prediction and probability of neonatal outcome in isolated congenital diaphragmatic hernia using multiple ultrasound parameters.

OBJECTIVES: To evaluate the accuracy and probabilities of different fetal ultrasound parameters to predict neonatal outcome in isolated congenital diaphragmatic hernia (CDH). METHODS: Between January 2004 and December 2010, we evaluated prospectively 108 fetuses with isolated CDH (82 left-sided and 26 right-sided). The following parameters were evaluated: gestational age at diagnosis, side of the diaphragmatic defect, presence of polyhydramnios, presence of liver herniated into the fetal thorax (liver-up), lung-to-head ratio (LHR) and observed/expected LHR (o/e-LHR), observed/expected contralateral and total fetal lung volume (o/e-ContFLV and o/e-TotFLV) ratios, ultrasonographic fetal lung volume/fetal weight ratio (US-FLW), observed/expected contralateral and main pulmonary artery diameter (o/e-ContPA and o/e-MPA) ratios and the contralateral vascularization index (Cont-VI). The outcomes were neonatal death and severe postnatal pulmonary arterial hypertension (PAH). RESULTS: Neonatal mortality was 64.8% (70/108). Severe PAH was diagnosed in 68 (63.0%) cases, of which 63 died neonatally (92.6%) (P < 0.001). Gestational age at diagnosis, side of the defect and polyhydramnios were not associated with poor outcome (P > 0.05). LHR, o/e-LHR, liver-up, o/e-ContFLV, o/e-TotFLV, US-FLW, o/e-ContPA, o/e-MPA and Cont-VI were associated with both neonatal death and severe postnatal PAH (P < 0.001). Receiver-operating characteristics curves indicated that measuring total lung volumes (o/e-TotFLV and US-FLW) was more accurate than was considering only the contralateral lung sizes (LHR, o/e-LHR and o/e-ContFLV; P < 0.05), and Cont-VI was the most accurate ultrasound parameter to predict neonatal death and severe PAH (P < 0.001). CONCLUSIONS: Evaluating total lung volumes is more accurate than is measuring only the contralateral lung size. Evaluating pulmonary vascularization (Cont-VI) is the most accurate predictor of neonatal outcome. Estimating the probability of survival and severe PAH allows classification of cases according to prognosis.

Nitrofen interferes with trophoblastic expression of retinol-binding protein and transthyretin during lung morphogenesis in the nitrofen-induced congenital diaphragmatic hernia model.

BACKGROUND: Retinoids play a key role in lung development. Retinoid signaling pathway has been shown to be disrupted in the nitrofen model of congenital diaphragmatic hernia (CDH) but the exact mechanism is not clearly understood. Retinol-binding protein (RBP) and transthyretin (TTR) are transport proteins for delivery of retinol to the tissues via circulation. Previous studies have shown that pulmonary retinol levels are decreased during lung morphogenesis in the nitrofen CDH model. In human newborns with CDH, both retinol and RBP levels are decreased. It has been reported that maternal RBP does not cross the placenta and the fetus produces its own RBP by trophoblast. RBP and TTR synthesized in the fetus are essential for retinol transport to the developing organs including lung morphogenesis. We hypothesized that nitrofen interferes with the trophoblastic expression of RBP and TTR during lung morphogenesis and designed this study to examine the trophoblastic expression of RBP and TTR, and the total level of RBP and TTR in the lung in the nitrofen model of CDH. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal lungs and placenta harvested on D21 and divided into two groups: control (n = 8) and nitrofen with CDH (n = 8). Total lung RBP and TTR levels using protein extraction were compared with enzyme linked immunoassay (ELISA). Immunohistochemistry was performed to evaluate trophoblastic RBP and TTR expression. RESULTS: Total protein levels of lung RBP and TTR were significantly lower in CDH (0.26 ± 0.003 and 6.4 ± 0.5 µg/mL) compared with controls (0.4 ± 0.001 and 9.9 ± 1.6 µg/mL, p < 0.05). In the control group, immunohistochemical staining showed strong immunoreactivity of RBP and TTR in the trophoblast compared to CDH group. CONCLUSIONS: Decreased trophoblast expression of retinol transport proteins suggest that nitrofen may interfere with the fetal retinol transport resulting in reduced pulmonary RBP and TTR levels and causing pulmonary hypoplasia in CDH.

Fetal cardiac function: technical considerations and potential research and clinical applications.

Fetal echocardiography was initially used to detect structural anomalies but has more recently also been proposed to assess fetal cardiac function. This review summarizes technical issues and limitations in fetal cardiac function evaluation, as well as its potential research and clinical applications. Functional echocardiography has been demonstrated to select high-risk populations and to be associated with outcome in several fetal conditions including intrauterine growth restriction, twin-to-twin transfusion syndrome, maternal diabetes, and congenital diaphragmatic hernia. Fetal heart evaluation is challenging due to the smallness and high heart rate of the fetus and restricted access to the fetus far from the transducer. Due to these limitations and differences in cardiac function which are related to fetal maturation, cardiovascular parameters should be validated in the fetus and used with caution. Despite these precautions, in expert hands and with appropriate ultrasound equipment, evaluation of cardiac function is feasible in most fetuses. Functional fetal echocardiography is a promising tool that may soon be incorporated into clinical practice. Research is warranted to further refine the contribution of fetal cardiac assessment to the diagnosis, monitoring, or prediction of outcomes in various fetal conditions.

Three-dimensional ultrasound fetal lung volumes and infant respiratory outcome: a prospective observational study.

OBJECTIVE: To determine if fetal lung volumes (FLVs), determined by three-dimensional rotational ultrasound and virtual organ computer-aided analysis software (vocal), correlated with neonatal respiratory outcomes in surviving infants who had a high risk [fetuses with congenital diaphragmatic hernia (CDH)], lower risk [fetuses with anterior wall defects (AWDs)] and no risk (controls) of abnormal antenatal lung growth. DESIGN: Prospective observational study. SETTING: Tertiary fetal medicine and neonatal intensive care units. POPULATION: Sixty fetuses (25 with CDH, 25 with AWDs and ten controls). METHODS: FLVs were measured and expressed as the percentage of the observed compared with the expected for gestational age. MAIN OUTCOME MEASURES: Neonatal respiratory outcome was determined by the duration of supplemental oxygen, mechanical ventilation and dependencies, and assessment of lung volume using a gas dilution technique to measure functional residual capacity (FRC). RESULTS: The infants with CDH had lower FLV results than both the infants with AWDs (P=0.05) and the controls (P<0.05). The infants with CDH had longer durations of mechanical ventilation (P<0.001) and supplementary oxygen (P<0.001) dependence, compared with infants with AWDs. The infants with CDH had a lower median FRC than both the infants with AWDs (P<0.001) and the controls (P<0.001). FLV results correlated significantly with the durations of dependency on ventilation (r= -0.744, P<0.01) and oxygen (r= -0.788, P<0.001), and with FRC results (r=0.429, P=0.001). CONCLUSIONS: These results suggest that FLVs obtained using three-dimensional rotational ultrasound might be useful in predicting neonatal respiratory outcome in surviving infants who had varying risks of abnormal lung growth. Larger and more comprehensive studies are needed to clarify the role that lung volume measurements have in assessing lung function and growth.

Re-evaluation of stomach position as a simple prognostic factor in fetal left congenital diaphragmatic hernia: a multicenter survey in Japan.

OBJECTIVES: To document outcome and to explore prognostic factors in fetal left congenital diaphragmatic hernia (CDH). METHODS: This was a multicenter retrospective study of 109 patients with prenatally diagnosed isolated left CDH born between 2002 and 2007. The primary outcome was intact discharge, defined as discharge from hospital without major morbidities, such as a need for respiratory support including oxygen supplementation, tube feeding, parenteral nutrition or vasodilators. All patients were managed at perinatal centers with immediate resuscitation, gentle ventilation (mostly with high-frequency oscillatory ventilation) and surgery after stabilization. Prenatal data collected included liver and stomach position, lung-to-head ratio, gestational age at diagnosis and presence or absence of polyhydramnios. Stomach position was classified into four grades: Grade 0, abdominal; Grade 1, left thoracic; Grade 2, less than half of the stomach herniated into the right chest; and Grade 3, more than half of the stomach herniated into the right chest. RESULTS: Overall intact discharge and 90-day survival rates were 65.1% and 79.8%, respectively. Stomach herniation was classified as Grade 0 in 19.3% of cases, Grade 1 in 45.9%, Grade 2 in 13.8% and Grade 3 in 21.1%. Multivariate analysis revealed that liver position was the strongest prognostic variable for intact discharge, followed by stomach position. Based on our results, we divided patients into three groups according to liver (up vs. down) and stomach (Grade 0-2 vs. Grade 3) position. Intact discharge rates declined significantly from liver-down (Group I), to liver-up with stomach Grade 0-2 (Group II), to liver-up with stomach Grade 3 (Group III) (87.0%, 47.4% and 9.5% of cases, respectively). CONCLUSION: Current status and outcomes of prenatally diagnosed left CDH in Japan were surveyed. Stomach herniation into the right chest was not uncommon and its grade correlated with outcome. The combination of liver and stomach positions was useful to stratify patients into three groups (Group I-III) with different prognoses.

Late administration of antenatal vitamin A promotes pulmonary structural maturation and improves ventilation in the lamb model of congenital diaphragmatic hernia.

PURPOSE: The lungs in congenital diaphragmatic hernia (CDH) are hypoplastic and immature making respiratory support one of the most challenging aspects of caring for these neonates. Vitamin A is essential for normal lung growth and development. It also promotes alveolarization. The aim of this study is to investigate the effects of antenatal vitamin A on lung growth and alveolarization and ventilation in the lamb model of CDH. METHODS: This study was approved by the Animal Care Committee of the State University of New York at Buffalo, and conforms to the National Institute of Health guidelines. Diaphragmatic defects were created at 79-81 days gestation. Group 1 lambs (CDH, n = 5) were untreated. In group 2 (CDH + vitamin A, n = 6) and group 3 lambs (control + vitamin A, n = 3) right jugular venous catheters were inserted at 118-120 days and retinyl palmitate (vitamin A) was administered until 135 days. The control group (n = 5) consisted of twin littermates. Lambs were delivered at 136-139 days and ventilated for 2 h according to a set protocol. The left lungs were harvested and fixed for histology. RESULTS: Lung compliance was significantly higher in CDH + vitamin A (median 0.27, range 0.1-0.48 ml/cmH(2)O/kg) versus CDH lambs (median 0.07, range 0.07-0.18 ml/cmH(2)O/kg), P < 0.05. At 1 h CDH + vitamin A lambs experienced significantly lower PaCO(2) (median 115, range 35-194 mmHg vs. median 192, range 168-234 mmHg) and higher arterial pH (median 7.0, range 6.74-7.35 vs. median 6.73, range 6.5-6.81) than CDH lambs, P < 0.05. The lung weight to body weight ratio of CDH + vitamin A lambs was significantly less than that of CDH lambs (P < 0.05). Histology showed small thick walled air-spaces and no true alveoli in CDH lambs. In contrast, true alveoli and thinning of the inter-alveolar septums were seen in CDH + vitamin A lambs. CONCLUSION: This is the first study to demonstrate an improvement in lung function and structural maturation when antenatal vitamin A is given in a surgical model of CDH.