Comparison of fetal lung area to head circumference ratio with lung volume in the prediction of postnatal outcome in diaphragmatic hernia

Timing of magnetic resonance imaging in pregnancy for outcome prediction in congenital diaphragmatic hernia

PURPOSE

To evaluate the impact of the timing of MRI on the prediction of survival and morbidity in patients with CDH, and whether serial measurements have a beneficial value.

METHODS

This retrospective cohort study was conducted in two perinatal centers, in Germany and Italy. It included 354 patients with isolated CDH having at least one fetal MRI. The severity was assessed with the observed-to-expected total fetal lung volume (o/e TFLV) measured by two experienced double-blinded operators. The cohort was divided into three groups according to the gestational age (GA) at which the MRI was performed (< 27, 27-32, and  > 32 weeks' gestation [WG]). The accuracy for the prediction of survival at discharge and morbidity was analyzed with receiver operating characteristic (ROC) curves. Multiple logistic regression analyses and propensity score matching examined the population for balance. The effect of repeated MRI was evaluated in ninety-seven cases.

RESULTS

There were no significant differences in the prediction of survival when the o/e TFLV was measured before 27, between 27 and 32, and after 32 WG (area under the curve [AUC]: 0.77, 0.79, and 0.77, respectively). After adjustment for confounding factors, it was seen, that GA at MRI was not associated with survival at discharge, but the risk of mortality was higher with an intrathoracic liver position (adjusted odds ratio [aOR]: 0.30, 95% confidence interval [95%CI] 0.12-0.78), lower GA at birth (aOR 1.48, 95%CI 1.24-1.78) and lower o/e TFLV (aOR 1.13, 95%CI 1.06-1.20). ROC curves showed comparable prediction accuracy for the different timepoints in pregnancy for pulmonary hypertension, the need of extracorporeal membrane oxygenation, and feeding aids. Serial measurements revealed no difference in change rate of the o/e TFLV according to survival.

CONCLUSION

The timing of MRI does not affect the prediction of survival rate or morbidity as the o/e TFLV does not change during pregnancy. Clinicians could choose any gestational age starting mid second trimester for the assessment of severity and counseling.

Fetal lung MRI and features predicting post-natal outcome: a scoping review of the current literature

The outcome for infants with fetal lung pathologies not only depends on the nature of the pathology, but the impact it has on the developing lungs. The main prognostic factor is the degree of pulmonary hypoplasia, but this is not detectable pre-natally. Imaging techniques aim to simulate these features with a variety of surrogate measurements, including lung volume and MRI signal intensity. Despite the complexity of the various research studies and lack of consistent methodology, this scoping review aims to summarise current applications, and promising techniques requiring further investigation.

The role of magnetic resonance imaging in the diagnosis and prognostic evaluation of fetuses with congenital diaphragmatic hernia

In recent years, magnetic resonance imaging (MRI) has largely increased our knowledge and predictive accuracy of congenital diaphragmatic hernia (CDH) in the fetus. Thanks to its technical advantages, better anatomical definition, and superiority in fetal lung volume estimation, fetal MRI has been demonstrated to be superior to 2D and 3D ultrasound alone in CDH diagnosis and outcome prediction. This is of crucial importance for prenatal counseling, risk stratification, and decision-making approach. Furthermore, several quantitative and qualitative parameters can be evaluated simultaneously, which have been associated with survival, postnatal course severity, and long-term morbidity.

CONCLUSION

Fetal MRI will further strengthen its role in the near future, but it is necessary to reach a consensus on indications, methodology, and data interpretation. In addition, it is required data integration from different imaging modalities and clinical courses, especially for predicting postnatal pulmonary hypertension. This would lead to a comprehensive prognostic assessment.

WHAT IS KNOWN

• MRI plays a key role in evaluating the fetal lung in patients with CDH. • Prognostic assessment of CDH is challenging, and advanced imaging is crucial for a complete prenatal assessment and counseling.

WHAT IS NEW

• Fetal MRI has strengthened its role over ultrasound due to its technical advantages, better anatomical definition, superior fetal lung volume estimation, and outcome prediction. • Imaging and clinical data integration is the most desirable strategy and may provide new MRI applications and future research opportunities.

Do Serial Sonographic Assessments of Fetuses with Isolated Congenital Diaphragmatic Hernia Help Us Predict Survival?

OBJECTIVE

The aim of this study was to assess the ability of serial prenatal sonographic measurements, and specifically changes in the observed-to-expected lung-to-head ratio (O/E LHR) throughout gestation and to predict survival in congenital diaphragmatic hernia (CDH).

METHODS

Retrospective study of CDH fetuses evaluated prenatally and treated postnatally in a single tertiary center, 2008-2020. Sonographic evaluations included side of herniation, liver involvement, and O/E LHR. All data were calculated to assess ability to predict survival.

RESULTS

Overall, 94 fetuses were evaluated prenatally and delivered in our medical center. Among them, 75 had isolated CDH and 19 nonisolated. CDH was categorized as left (n = 76; 80.8%), right (n = 16; 17.0%), or bilateral (n = 2; 2.2%). Overall perinatal survival rate was 57% for all live-born infants, 68% in isolated CDH, and 40% in nonisolated (excluding 2 cases that underwent fetoscopic endoluminal tracheal occlusion and did not survive). The O/E LHR was lower in cases with perinatal death compared to survivors. In cases with multiple evaluations, the minimal O/E LHR was the most accurate predictor of survival and need for perinatal extracorporeal membrane oxygenation (ECMO) support. This remained significant when excluding twin pregnancies or when evaluating only isolated left CDH. In addition to disease severity, the side of herniation and liver position was associated with preoperative mortality.

CONCLUSION

O/E LHR is associated with perinatal survival. In cases with multiple evaluations, the minimal O/E LHR is the most accurate and significant predictor of perinatal mortality and need for ECMO support.

Impact of fetal endoscopic tracheal occlusion in fetuses with congenital diaphragmatic hernia and moderate lung hypoplasia

OBJECTIVE

To assess the effect of Fetal Endoscopic Tracheal Occlusion (FETO) on neonatal survival in fetuses with left congenital diaphragmatic hernia (CDH) and moderate lung hypoplasia.

STUDY DESIGN

CDH fetuses with moderate pulmonary hypoplasia (observed/expected lung area to head ratio between 26% and 35%, or between 36% and 45% with liver herniation) were prospectively recruited. Included patients were matched to a control group who were ineligible for FETO. Primary outcomes were survival at 28 days, at discharge, and at 6 months of age, respectively.

RESULTS

58 cases were recruited, 29 treated with FETO and 29 matched controls. Median gestational age (GA) at balloon placement and removal were 29.6 and 33.6 weeks, respectively. FETO group showed significantly lower GA at delivery (35.2 vs. 37.1 weeks, respectively, p < 0.01), higher survival at 28 days (51.7 vs. 24.1%, respectively, p = 0.03), at discharge (48.3 vs. 24.1%, respectively, p = 0.06), and at six months of age (41.4 vs. 24.1%, respectively, p = 0.16), and significantly lower length of ventilatory support (17.8 vs. 32.3 days, p = 0.01) and NICU stay (34.2 vs. 58.3 days, p = <0.01) compared to controls.

CONCLUSION

FETO was associated with a non-significant increase in survival and significantly lower neonatal respiratory morbidity among CDH fetuses with moderate lung hypoplasia.

The Chest Radiographic Thoracic Area Can Serve as a Prediction Marker for Morbidity and Mortality in Infants With Congenital Diaphragmatic Hernia

Objective: Valid postnatal prediction parameters for neonates with congenital diaphragmatic hernia (CDH) are lacking, but recently, the chest radiographic thoracic area (CRTA) was proposed to predict survival with high sensitivity. Here, we evaluated whether the CRTA correlated with morbidity and mortality in neonates with CDH and was able to predict these with higher sensitivity and specificity than prenatal observed-to-expected (O/E) lung-to-head ratio (LHR). Methods: In this retrospective cohort study, all neonates with CDH admitted to our institution between 2013 and 2019 were included. The CRTA was measured using the software Horos (V. 3.3.5) and compared with O/E LHR diagnosed by fetal ultrasonography in relation to outcome parameters including survival, extracorporeal membrane oxygenation (ECMO) support, and chronic lung disease (CLD). Results: In this study 255 neonates were included with a survival to discharge of 84%, ECMO support in 46%, and 56% developing a CLD. Multiple regression analysis demonstrated that the CRTA correlates significantly with survival (p = 0.001), ECMO support (p < 0.0001), and development of CLD (p = 0.0193). The CRTA displayed a higher prognostic validity for survival [area under the curve (AUC) = 0.822], ECMO support (AUC = 0.802), and developing a CLD (AUC = 0.855) compared with the O/E LHR. Conclusions: Our data suggest that the postnatal CRTA might be a better prognostic parameter for morbidity and mortality than the prenatal O/E LHR.

Survival outcome in severe left-sided congenital diaphragmatic hernia with and without fetal endoscopic tracheal occlusion in a country with suboptimal neonatal management

OBJECTIVE

To evaluate the impact of fetal endoscopic tracheal occlusion (FETO) on improving survival of fetuses with severe left-sided congenital diaphragmatic hernia (CDH), as compared with contemporaneous cases managed expectantly during pregnancy, in a country with suboptimal neonatal management.

METHODS

In this prospective cohort study, consecutive fetuses with isolated left-sided CDH, normal karyotype and severe pulmonary hypoplasia (defined as liver herniation and observed/expected lung-to-head circumference ratio below 26%) were selected for FETO at less than 32 weeks of gestation in a single tertiary referral center in Queretaro, Mexico. Postnatal outcome (survival up to 28 days after birth) was compared between fetuses treated with FETO and contemporaneous cases with similar lung size managed expectantly during pregnancy.

RESULTS

Twenty-five fetuses with isolated severe left-sided CDH treated with FETO were matched individually with 25 cases managed expectantly during pregnancy. Endotracheal placement of the balloon was performed successfully on the first attempt in all cases. The median gestational age (GA) at balloon placement was 29.1 (range, 25.6-31.8) weeks and 34.1 (range, 30.0-36.1) weeks at balloon removal. There were no technical problems with the introduction or removal of the balloon in any cases. The median GA at delivery was significantly lower in the group treated with FETO than in those managed expectantly (35.3 vs 37.7 weeks; P = 0.04). The survival rate was significantly higher in the group treated with FETO than in those without fetal intervention (32% vs 0%; P < 0.001).

CONCLUSION

In settings with suboptimal neonatal management, FETO was associated with improved neonatal survival in fetuses with isolated left-sided CDH and severe pulmonary hypoplasia. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal prediction of postnatal survival in fetuses with congenital diaphragmatic hernia using MRI: lung volume measurement, signal intensity ratio, and effect of experience

Objective: To evaluate various signal intensity ratios in isolated congenital diaphragmatic hernia (CDH) and to compare their potential in predicting survival with that of the observed-to-expected (O/E) ratio of total fetal lung volume (TFLV) using magnetic resonance imaging (MRI) measurements. Our second objective was to evaluate the impact of operator's experience in comparing the prediction of postnatal survival by O/E-TFLV.Methods: In 75 conservatively managed CDH fetuses and in 50 who underwent fetoscopic endoluminal tracheal occlusion (FETO), the fetal lung-to-amniotic fluid, lung-to-liver, lung-to-muscle, lung-to-spinal fluid signal intensity ratios, respectively LAFSIR, LLSIR, LMSIR, and LSFSIR, were measured, as was O/E-TFLV. Receiver operating characteristic (ROC) curves were constructed and used to compare the various signal intensity ratios with O/E-TFLV in the prediction of postnatal survival. In 72 MRI lung volumes assessed by the referring radiologists in Paris and Lille and secondarily by our expert radiologist in Brussels (M.M.C.) using the same MRI examinations, ROC curves were constructed and used to compare the value of O/E-TFLV determined by the two centers in the prediction of postnatal survival.Results: In the total cohort of CDH fetuses, O/E-TFLV and LLSIR were predictive of postnatal survival whereas in the conservatively managed group O/E-TFLV, LLSIR, and LMSIR predicted postnatal survival. O/E-TFLV predicted postnatal survival far better than the signal intensity ratios: area under the ROC curve for prediction by O/E-TFLV in the total cohort was 0.866 (p < .001; standard error = 0.031). The area under the ROC curve for prediction of postnatal survival using O/E-TFLV by MRI evaluated at the referral centers was 0.640 (p = 102; standard error = 0.085), and with O/E-TFLV reevaluated by M.M.C., it was 0.872 (p < .001; standard error = 0.061). Pairwise comparison showed a significant difference between the areas under the ROC curves (difference = 0.187, p = .012; standard error = 0.075).Conclusion: In fetuses with CDH with/without FETO, LLSIR was significantly correlated with the prediction of postnatal survival. However, measurement of O/E-TFLV was far better in predicting postnatal outcome. Operator experience in measurement of lung volumes using MRI seem to play a role in the predictive value of the technique.

Reproducibility of Liver-to-Thorax Area Ratio Ultrasound Measurements in Congenital Diaphragmatic Hernia

OBJECTIVES

The aim of this study was to investigate the reproducibility of a standardized method to assess the ultrasound liver-to-thoracic area ratio in fetuses with congenital diaphragmatic hernia.

METHODS

We selected 24 images of 9 fetuses diagnosed with left-sided at our institution between January 2010 and December 2017. Eight operators (1 maternal-fetal medicine specialist and 7 sonographers) reviewed the selected images and assessed the ultrasound liver-to-thoracic area ratio according to a standardized protocol. We evaluated the correlation between operators using the intraclass correlation coefficient and compared agreement between the sonographers and a physician with experience in measuring the ultrasound liver-to-thoracic area ratio using a Bland-Altman analysis.

RESULTS

Good intraoperator reproducibility was observed for the standardized ultrasound liver-to-thoracic area ratio (intraclass correlation coefficient, 0.78). Good agreement among sonographers and the physician was also observed for the standardized measurements (bias, 0.01; precision, 0.03; limits of agreement, -0.05 to + 0.07).

CONCLUSIONS

We demonstrated that good intraoperator and interoperator reproducibility of ultrasound liver-to-thoracic area ratio assessment is feasible after standardizing the method in our center.

Longitudinal changes in lung size and intrapulmonary-artery Doppler during the second half of pregnancy in fetuses with congenital diaphragmatic hernia

OBJECTIVES

The objectives of the study are to evaluate longitudinal changes in lung size and intrapulmonary-artery (IPa) Doppler in fetuses with congenital diaphragmatic hernia (CDH) and assess their contribution in predicting neonatal survival.

METHODS

The observed/expected lung-to-head ratio (O/E-LHR) and IPa-pulsatility index (PI) and peak early diastolic reversed flow (PEDRF) were evaluated in a cohort of left-sided CDH fetuses managed expectantly during pregnancy. Longitudinal changes were analyzed by multilevel analysis, and their value to predict survival using the multiple logistic regression and decision-tree analysis was assessed.

RESULTS

A total of 232 scans were performed on 69 CDH fetuses. The O/E-LHR values remained unchanged during fetal monitoring, whereas IPa-PI and PEDRF showed a progressive increase throughout follow-up, becoming abnormal on average at 30 weeks of gestation. Absent/reversed end-diastolic velocity (EDV) in the IPa was observed in 20.3%. O/E-LHR and IPa Doppler indices were significantly associated with probability of survival (O/E-LHR ≥ 26%, odds ratio [OR] 19.0; IPa-PI <+2.0 z score, OR 3.0; and positive EDV, OR 7.4). All cases with IPa-reversed EDV died after birth.

CONCLUSION

While lung size remains stable during pregnancy, CDH fetuses show progressive deterioration in intrapulmonary blood flow. IPa Doppler evaluation may aid in predicting survival of CDH fetuses managed expectantly during pregnancy.

Reproducibility of Lung-to-Head Ratio Ultrasound Measurements in Congenital Diaphragmatic Hernia

OBJECTIVES

This study investigated the reproducibility of standardization of lung-to-head ratio measurements in congenital diaphragmatic hernia (CDH) at our center among sonographers after we standardized the method.

METHODS

We reviewed ultrasound images of 12 fetuses with CDH at Mayo Clinic from 2010 to 2016. Nine operators (1 maternal-fetal medicine specialist with experience in measuring the lung-to-head ratio and 8 sonographers), who were blinded to previous findings, reviewed 33 selected images from 12 fetuses with left CDH. The method for lung-to-head ratio measurement was standardized before starting the measurements. The lung-to-head ratio was assessed by different methods to obtain the lung areas: anteroposterior, longest, and area tracing. We evaluated the correlation between operators using the intraclass correlation coefficient (ICC). We also compared agreement between the sonographers and a physician with experience in measuring the lung-to-head ratio using a Bland-Altman analysis.

RESULTS

The methods with the best interoperator reproducibility were the standardized anteroposterior lung-to-head ratio (ICC, 0.69) and the standardized lung-to-head ratio tracing (ICC, 0.65) compared to the longest lung-to-head ratio (ICC, 0.56). The standardized lung-to-head ratio tracing had the best agreement among sonographers and the physician (bias, 0.11; limits of agreement, -0.27 to +0.49) than the anteroposterior lung-to-head ratio (bias, 0.35; limits of agreement, -0.13 to + 0.83) and the longest lung-to-head ratio (bias, 0.27; limits of agreement, -0.35 to +0.89).

CONCLUSIONS

We demonstrated that the lung-to-head ratio tracing method has high interoperator reproducibility and the best agreement among the operators at our center. Further multicenter studies are necessary to confirm our results.

Fetal lung size after thoracoamniotic shunting reflects survival in primary fetal hydrothorax with hydrops

AIM

To assess the role of lung size and abnormal Doppler findings in the umbilical artery (UA) in determining the outcomes of fetuses with primary fetal hydrothorax (FHT) associated with hydrops who underwent thoracoamniotic shunting (TAS).

METHODS

This was a retrospective study at a single center. We included cases of primary FHT with hydrops who underwent TAS at our hospital between 2004 and 2016. We assessed the relationship between mortality until 28 days after birth and ultrasound findings, including absent or reversed end-diastolic velocity (AREDV) in the UA and the lung-to-thorax transverse area ratio (LTR), before and after TAS.

RESULTS

Forty-one cases of primary FHT with hydrops underwent TAS. The median (range) gestational age at TAS was 28.5 (19.3-33.8) weeks. Bilateral pleural effusion was observed in 39 cases (95.1%). Among the 41 cases, 19 (46.4%) survived, 11 (26.8%) died in utero, and 11 (26.8%) died in the neonatal period. AREDV in the UA before and after TAS were not associated with mortality (P = 0.32 and 0.47, respectively). The odds ratio for mortality in LTR 0.2-0.3 before TAS was 0.62 (vs LTR < 0.2, P = 0.45) and that in LTR 0.2-0.3 and > 0.3 after TAS were 0.27 and 0.06, respectively (vs LTR < 0.2, P for trend <0.01).

CONCLUSION

A larger LTR after TAS was significantly associated with a better prognosis in hydropic primary FHT. The fetal lung size after the procedure may be a prognostic factor of primary FHT.

Foetoscopic endotracheal occlusion (FETO) for severe isolated left-sided congenital diaphragmatic hernia: single center Polish experience

OBJECTIVE

To present early experience with foetoscopic endotracheal occlusion (FETO) for congenital diaphragmatic hernia (CDH) in a new center in Poland.

METHODS

This was a prospective study in singleton pregnancies with CDH treated by FETO between 2014 and 2016 in the Medical University of Warsaw, Poland. FETO was carried out at 25.6-30.1 (median 27.7) weeks' gestation in 28 consecutive cases of isolated left-sided CDH with observed over expected lung area to head circumference ratio (o/e LHR) of 20.7-22.6 (median 18.9).

RESULTS

Neonatal survival rate was 46.4% (13/28) at the time of discharge. The median o/e LHR the day before balloon removal was 33.4 (19.7-57.5) and median gestational age at delivery was 34.7 (29.0-38.1) weeks. Comparison of the survivors and perinatal deaths showed no significant differences in median gestational age at FETO or median o/e LHR before FETO, but higher median gestational age at delivery (35.9, range 32.7-38.1 weeks vs. 33.2, range 29.0-37.7 weeks; p = .007) and o/e LHR before balloon removal (33.7, range 28.3-57.5 vs. 30.9, range 19.7-37.5; p = .017).

CONCLUSIONS

FETO was implemented successfully in Poland and the survival rate (46.4%) is similar to that reported in other centers. Important determinants of survival were gestational age at delivery and pulmonary response to FETO. The rate of preterm prelabor rupture of membranes (PPROM) in our series is similar to the larger series treated with FETO in the pioneering centers of this technique.

Fetal imaging and therapy for CDH-Current status

In congenital diaphragmatic hernia (CDH), herniation of the abdominal organs into the fetal chest causes pulmonary hypoplasia and pulmonary hypertension, the main causes of neonatal mortality. As antenatal ultrasound screening improves, the risk of postnatal death can now be better predicted, allowing for the identification of fetuses that might most benefit from a prenatal intervention. Fetoscopic tracheal occlusion is being evaluated in a large international randomized controlled trial. We present the antenatal imaging approaches that can help identify fetuses that might benefit from antenatal therapy, and review the evolution of fetal surgery for CDH to date.

Separate Evaluation of the Ipsilateral and Contralateral MR Fetal Lung Volume in Patients With Congenital Diaphragmatic Hernia

OBJECTIVE

Our study had two objectives. First, we separately evaluated observed-to-expected MR fetal lung volume (FLV) of lungs ipsilateral and contralateral to a congenital diaphragmatic hernia (CDH). Second, we compared the prognostic value of observed-to-expected MR FLV of the ipsilateral and contralateral lungs with that of observed-to-expected MR FLV of both lungs with respect to survival, need for extracorporeal membrane oxygenation (ECMO), and development of chronic lung disease (CLD).

MATERIALS AND METHODS

We evaluated observed-to-expected MR FLV of the lung ipsilateral to the diaphragmatic defect as well as in the contralateral lung in 107 fetuses with isolated CDH. ROC analysis and logistic regression analysis were performed to assess the prognostic value of the observed-to-expected MR FLV for association with outcome.

RESULTS

In all fetuses with CDH, values in the ipsilateral (mean observed-to-expected MR FLV ± SD, 9.4% ± 9.6%) and the contralateral lung (mean observed-to-expected MR FLV, 48.9% ± 18.5%; p < 0.0001) were significantly lower than values measured in healthy fetuses. Observed-to-expected MR FLV of both lungs and of the contralateral and ipsilateral lung revealed significant differences regarding survival (p < 0.0001, p < 0.0001, and p = 0.0170, respectively), need for ECMO (p < 0.0001, p < 0.0001, and p = 0.0051, respectively), and development of CLD (p = 0.0004, p = 0.0002, and p = 0.0460, respectively). Compared with the observed-to-expected MR FLV of both lungs, the observed-to-expected MR FLV of the contralateral lung showed a slightly higher prognostic accuracy regarding survival (AUC = 0.859 vs 0.825) and development of CLD (AUC = 0.734 vs 0.732) and a similar prognostic accuracy regarding need for ECMO (AUC = 0.805 vs 0.826). Observed-to-expected MR FLV of the ipsilateral lung did not show good prognostic value regarding survival (AUC = 0.617), need for ECMO (AUC = 0.673), and development of CLD (AUC = 0.636). These AUCs were significantly smaller than the AUCs resulting from the observed-to-expected MR FLV of both lungs (each p < 0.05) and considerably smaller than the AUCs of the observed-to-expected MR FLV of the contralateral lung (each p < 0.10).

CONCLUSION

Patients with CDH showed a substantially lower observed-to-expected MR FLV of both lungs compared with healthy fetuses. The observed-to-expected MR FLV of both lungs as well as of the lung contralateral to the CDH were reliable prenatal predictors of survival, need for ECMO, and development of CLD.

Growth Patterns of Fetal Lung Volumes in Healthy Fetuses and Fetuses With Isolated Left-Sided Congenital Diaphragmatic Hernia

OBJECTIVES

To evaluate fetal lung growth using 3-dimensional sonography in healthy fetuses and those with congenital diaphragmatic hernia (CDH).

METHODS

Right and total lung volumes were serially evaluated by 3-dimensional sonography in 66 healthy fetuses and 52 fetuses with left-sided CDH between 20 and 37 weeks' menstrual age. Functions fitted to these parameters were compared for 2 groups: (1) healthy versus those with CDH; and (2) fetuses with CHD who survived versus those who died.

RESULTS

Fetal right and total lung volumes as well as fetal observed-to-expected right and total lung volume ratios were significantly lower in fetuses with CDH than healthy fetuses (P< .001) and in those fetuses with CDH who died (P< .001). The observed-to-expected right and total lung volume ratios did not vary with menstrual age in healthy fetuses or in those with CDH (independent of outcome).

CONCLUSIONS

Lung volume rates were lower in fetuses with left-sided CDH compared to healthy fetuses, as well as in fetuses with CDH who died compared to those who survived. The observed-to-expected right and total lung volume ratios were relatively constant throughout menstrual age in fetuses with left-sided CDH, suggesting that the origin of their lung growth abnormalities occurred before 20 weeks and did not progress. The observed-to-expected ratios may be useful in predicting the outcome in fetuses with CDH independent of menstrual age.

Correlation of Observed-to-Expected MRI Fetal Lung Volume and Ultrasound Lung-to-Head Ratio at Different Gestational Times in Fetuses With Congenital Diaphragmatic Hernia

OBJECTIVE

The purpose of this study is to compare the observed-to-expected MRI fetal lung volume and the observed-to-expected ultrasound lung-to-head ratio intraindividually for prediction of survival, the need for extracorporeal membrane oxygenation (ECMO) therapy, and the development of chronic lung disease (CLD) at different times of gestation (< 28, 28-32, and > 32 weeks) in fetuses with congenital diaphragmatic hernia (CDH), and to analyze the intraindividual correlation of observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio.

MATERIALS AND METHODS

Two hundred one fetuses were included in our study. Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio were calculated for 270 MRI and ultrasound examinations performed within 72 hours of each other. The prognostic accuracy of observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio was assessed by performing ROC analysis. Correlation was determined using linear regression analysis.

RESULTS

The results revealed statistically significant differences between the observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio for the prediction of survival, the need for ECMO therapy, and the development of CLD in fetuses with left-sided CDH (p ≤ 0.0444), with the highest prognostic accuracy for survival (AUC = 0.863). Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio correlated statistically significantly (p < 0.0001) for left-sided CDH with correlation coefficients (r) of 0.71, 0.71, and 0.56 for early, intermediate, and late times of gestation, respectively. The correlation was not statistically significant at any time for right-sided CDH (p ≥ 0.3947; r ≤ 0.26).

CONCLUSION

Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio are valuable prognostic parameters for prenatal prediction of survival, the need for ECMO therapy, and the development of CLD in fetuses with left-sided CDH at all times of gestation. Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio correlate statistically significantly for left-sided CDH, and the correlation is best before 32 weeks' gestation, but they do not correlate statistically significantly for right-sided CDH.

Quantification of liver herniation in fetuses with isolated congenital diaphragmatic hernia using two-dimensional ultrasonography

OBJECTIVES

To describe a method of quantifying the amount of liver herniation in fetuses with isolated congenital diaphragmatic hernia (CDH) using two-dimensional ultrasonography and to correlate this finding with neonatal outcome.

METHODS

Ultrasound images obtained from 77 consecutive fetuses that presented with isolated CDH between January 2004 and July 2012 were reviewed. Liver herniation and thoracic area were measured in a cross-sectional plane of the fetal chest at the level of the four-chamber view of the heart (the same section as is used to measure the lung area-to-head circumference ratio) and the ultrasound-derived liver-to-thoracic area ratio (US-LiTR) was calculated by dividing the liver herniation area by the thoracic area. Receiver-operating characteristics (ROC) curve analysis was used to evaluate the performance of US-LiTR in predicting neonatal outcome (survival to 6 months after delivery and need for extracorporeal membrane oxygenation (ECMO)). In addition, the US-LiTR was compared with the magnetic resonance imaging (MRI)-derived volume ratio (MRI-LiTR) and percentage of liver herniation (MRI-%LH).

RESULTS

The overall neonatal mortality in the 77 cases with isolated CDH was 20.8% (16/77). ECMO was needed in 35.5% (27/76) of the newborns, with a survival rate of 52%. The US-LiTR was associated statistically with mortality (P < 0.01) and with the need for ECMO (P < 0.01). Good correlations were observed between US-LiTR and MRI-LiTR (r = 0.87; P < 0.001) and between US-LiTR and MRI-%LH (r = 0.90; P < 0.001). Based on ROC curve analysis, all three parameters had similar accuracy in predicting mortality (US-LiTR: area under the ROC curve (AUC), 0.78 (95% CI, 0.65-0.92), P < 0.01; MRI-LiTR: AUC, 0.77 (95% CI, 0.63-0.90), P < 0.01; MRI-%LH: AUC, 0.79 (95% CI, 0.65-0.92), P < 0.01, respectively) as well as the need for ECMO (US-LiTR: AUC, 0.72 (95% CI, 0.60-0.84), P < 0.01; MRI-LiTR: AUC, 0.73 (95% CI, 0.60-0.88), P < 0.01; MRI-%LH: AUC, 0.77 (95% CI, 0.64-0.89), P < 0.01, respectively).

CONCLUSIONS

Two-dimensional ultrasound measurement of the amount of liver herniation in fetuses with isolated CDH is feasible and demonstrates a predictive accuracy for neonatal outcome similar to that of MRI.

Longitudinal assessment of lung area measurements by two-dimensional ultrasound in fetuses with isolated left-sided congenital diaphragmatic hernia

OBJECTIVE

To evaluate lung growth in healthy fetuses and those with congenital diaphragmatic hernia (CDH) using two-dimensional (2D) ultrasound.

METHODS

Fetal right lung measurements obtained by 2D ultrasound between 19 and 37 weeks' gestation were evaluated longitudinally in 66 healthy fetuses and 52 fetuses with isolated left-sided CDH. Right lung areas were determined by the 'tracing' and 'longest-diameters' methods and, subsequently, lung area-to-head circumference ratios (LHRs) were calculated. Functions fitted to these size parameters with respect to gestational age were evaluated for three sets of group-wise comparisons: (1) healthy vs CDH fetuses; (2) different degrees of severity of CDH; and (3) CDH fetuses that survived vs those that died by 6 months postpartum.

RESULTS

There was a significantly slower increase in right lung areas and LHRs with advancing gestational age in CDH fetuses than in healthy individuals (P < 0.05). Compared to those with milder forms of CDH, lung areas and LHRs of fetuses with more severe forms displayed a smaller increase (P < 0.05) and LHRs of fetuses with severe CDH did not increase during pregnancy (P > 0.05). Individuals who died postpartum did not show any increase in LHR (P > 0.05) throughout gestation.

CONCLUSIONS

The right lung area and LHR, calculated using either the longest-diameters or tracing method, display reduced growth rates during gestation in cases of isolated left-sided CDH as compared with healthy fetuses. The growth curve characteristics of fetal lung areas and LHRs may be useful for predicting neonatal mortality.

Reference ranges for 2-dimensional sonographic lung measurements in healthy fetuses: a longitudinal study

OBJECTIVES

The purpose of this study was to establish reference ranges for 2-dimensional sonographic measurements of fetal lungs from longitudinal data.

METHODS

A total of 214 fetal lung measurements were longitudinally evaluated in 62 healthy fetuses between 20 and 36 weeks' menstrual age. Both right and left lung areas were measured in the heart 4-chamber view using lung area tracing and axis diameter methods. Multilevel modeling was used to evaluate the expected values and variability with respect to menstrual age and to generate reference ranges for the lung area, lung-to-head ratio, quantitative lung index, and observed-to-expected lung-to-head ratio for both lungs.

RESULTS

The expected values varied with menstrual age for all parameters. Variance was menstrual age dependent for all parameters except the longest diameter area measurements and their lung-to-head ratios.

CONCLUSIONS

Models are presented for expected 2-dimensional sonographic lung size parameters and their variance as a function of menstrual age. These data have been used to generate age-specific reference ranges for both measurements and indices.

Prenatal MRI fetal lung volumes and percent liver herniation predict pulmonary morbidity in congenital diaphragmatic hernia (CDH)

PURPOSE

The purpose of this study was to determine whether prenatal imaging parameters are predictive of postnatal CDH-associated pulmonary morbidity.

METHODS

The records of all neonates with CDH treated from 2004 to 2012 were reviewed. Patients requiring supplemental oxygen at 30 days of life (DOL) were classified as having chronic lung disease (CLD). Fetal MRI-measured observed/expected total fetal lung volume (O/E-TFLV) and percent liver herniation (%LH) were recorded. Receiver operating characteristic (ROC) curves and multivariate regression were applied to assess the prognostic value of O/E-TFLV and %LH for development of CLD.

RESULTS

Of 172 neonates with CDH, 108 had fetal MRIs, and survival was 76%. 82% (89/108) were alive at DOL 30, 46 (52%) of whom had CLD. Neonates with CLD had lower mean O/E-TFLV (30 vs.42%; p=0.001) and higher %LH (21.3±2.8 vs.7.1±1.8%; p<0.001) compared to neonates without CLD. Using ROC analysis, the best cutoffs in predicting CLD were an O/E-TFLV<35% (AUC=0.74; p<0.001) and %LH>20% (AUC=0.78; p<0.001). On logistic regression, O/E-TFLV<35% and a %LH>20% were highly associated with indicators of long-term pulmonary sequelae. On multivariate analysis, %LH was the strongest predictor of CLD in patients with CDH (OR: 10.96, 95%CI: 2.5-48.9, p=0.002).

CONCLUSION

Prenatal measurement of O/E-TFLV and %LH is predictive of CDH pulmonary morbidity and can aid in establishing parental expectations of postnatal outcomes.

New anatomical landmarks to study the relationship between fetal lung area and thoracic circumference by three-dimensional ultrasonography

OBJECTIVE

To evaluate the relation between total lung area (TLA) and thoracic circumference (TC) ratio by three-dimensional (3D) ultrasonography applying new anatomical landmarks as the fetal aorta and inferior angle of the scapula.

METHODS

A longitudinal prospective study was conducted with 56 uncomplicated pregnancies between 24 and 32 weeks of gestation. Polynomial regressions were used to evaluate the correlation between TC and gestational age (GA) as well as TC and estimated fetal weight (EFW). A simple linear regression was used to evaluate the correlation between TLA and Total thoracic area (TTA) and GA. The intraclass correlation coefficient (ICC) was used to assess the intra and interobserver variability.

RESULTS

127 examinations were performed. TC values ranged from 150 to 174 mm (mean 166 mm) at 24 weeks and 215-248 mm (mean 231 mm) at 32 weeks. The TLA/TC ratio ranged from a mean of 0.64 at 24 weeks (range 0.56-0.70) to 0.90 at 32 weeks gestation (range 0.79-1.01). The intraobserver variability using the ICC was of 0.919 for TC; 0.916 for TTA; 0.860 for right lung area (RLA) and 0.910 for left lung area (LLA). Interobserver reproducibility was with an ICC of 0.970 for TC; 0.984 for RLA and 0.910 for LLA.

CONCLUSIONS

Measurement of fetal TC and the relationship between TLA and TC by 3D-ultrasonography applying new anatomical landmarks shows good reproducibility and allows a new assessment of thoracic and lung growth.

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.

Current advances in prenatal imaging of congenital diaphragmatic [corrected] hernia

Congenital diaphragmatic hernia, despite advances in therapy, remains a complex condition with significant morbidity and mortality. The etiology of the disorder is still incompletely understood, though the pulmonary hypoplasia and pulmonary hypertension that develop secondarily must be overcome to improve survival. Prenatal US and fetal MRI have helped in the development of a greater understanding of this disease. Also with these modalities, measurement techniques have been developed in an attempt to provide prognosticators for the development of pulmonary hypoplasia and pulmonary hypertension. There is a broad range of approaches for performing these measurements, and variability among imaging centers is noted. Despite inconsistent approaches, these techniques have become the foundation for counseling and prenatal and postnatal therapy. It is hoped that with further research with prenatal US and fetal MRI and the development of innovative medical and surgical therapies that the morbidity and mortality of children with congenital diaphragmatic hernias can be significantly reduced.

Antenatal ultrasound prediction of pulmonary hypoplasia in congenital diaphragmatic hernia: correlation with pathology

OBJECTIVE

To examine the relationship between observed to expected (o/e) lung to head circumference ratio (LHR) and lung-to-body weight ratio (LBWR) in fetuses with congenital diaphragmatic hernia (CDH).

METHODS

All consecutive fetuses with CDH and termination of pregnancy for which a postmortem examination was available, examined at three institutions between 2000 and 2010, were included in the study. Contralateral fetal lung area was measured by two-dimensional ultrasonography using the longest axis method and the o/e-LHR was calculated based on the appropriate normal mean for gestational age (GA). Regression analysis was used to determine the significance of association between the LBWR and the o/e-LHR for left and right-sided cases, and subsequently the predicted LBWR in left-sided CDH was calculated using the regression equation. Regression analysis was used to investigate the effect on the proportional difference between the predicted and observed LBWR of GA at o/e-LHR, time gap between o/e-LHR and LBWR measurement, proportional weight of the ipsilateral compared with total lung weight, presence of associated anomalies and intrathoracic herniation of the liver.

RESULTS

There were 23 fetuses with left-sided and seven fetuses with right-sided CDH. In left-sided CDH, the LBWR and the o/e-LHR correlated significantly, following the linear equation: LBWR = 0.0043 + (0.0134 × o/e-LHR) (r = 0.52, P = 0.012), but this was not the case for right-sided CDH, for which LBWR followed the equation: LBWR = 0.0107 - (0.0014 × o/e-LHR) (r = 0.08, P = 0.862), where o/e-LHR is expressed as percentage. Regression analysis showed that the proportional difference between predicted and observed LBWR in left-sided CDH was significantly and independently associated with GA at o/e-LHR measurement and proportional weight of ipsilateral vs. total lung weight.

CONCLUSION

In left-sided CDH, o/e-LHR correlates well with LBWR irrespective of the length of time between o/e-LHR and LBWR measurement, presence of associated anomalies and intrathoracic herniation of the liver. Inconsistencies between the two measurements are mainly attributable to the contribution of the ipsilateral lung to the total lung weight. In right-sided CDH, o/e-LHR does not correlate with LBWR.

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.

Predictors of the need for extracorporeal membrane oxygenation and survival in congenital diaphragmatic hernia: a center's 10-year experience

OBJECTIVE

To determine the prenatal factors associated with the need for extracorporeal membrane oxygenation (ECMO) and neonatal survival in congenital diaphragmatic hernia (CDH).

STUDY DESIGN

A retrospective cohort study of all cases of CDH seen in our center between 1998 and 2008. Prenatal ultrasound and neonatal records were reviewed. Both univariable and logistic regression analyses were performed to determine the significant factors associated with the use of ECMO and survival.

RESULTS

Among 107 cases of CDH seen during the study period, 62 were evaluated prenatally in our center and 49 had information on all variables evaluated. The overall rate of ECMO use was 27/107 (25%) and survival rate was 53/107 (49.5%). The lung area to head circumference ratio (LHR) and gestational age (GA) at delivery were the only significant factors associated with ECMO use, and the LHR and absence of liver herniation were significantly associated with survival. LHR values under 1.0 were associated with 57% need for ECMO and 100% neonatal death. Although, overall, the observed:expected LHR (O:E LHR) was not significantly associated with ECMO use or survival, levels below 65% were associated with 58% need for ECMO (p = 0.004) and 100% neonatal death (p = 0.002).

CONCLUSION

The study confirms the LHR, GA at delivery and liver herniation as significant prenatal predictors of the need for ECMO or survival in cases with CDH. This information is helpful for counseling women with fetuses complicated by CDH.

Congenital diaphragmatic hernia: review of the literature in reflection of unresolved dilemmas

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a rare but clinically and scientifically challenging condition. The introduction of ultrasound has enabled early prenatal detection and consequently, hope of early therapeutic intervention.

AIM

We undertook the task to review the recent developments in understanding the pathology of CDH as well as the history and current management strategies to aid perinatologists in consultations with parents of CDH-affected foetuses.

STUDY DESIGN

A Medline search was undertaken of all reports and reviews published between 1980 and 2008 using MeSH search terms 'diaphragmatic hernia', 'congenital' and 'newborn'.

RESULTS

The true incidence of CDH is still difficult to estimate because of the high incidence of hidden mortality of CDH. Complete case ascertainment also poses difficulties in assessment of the impact of new therapeutic modalities on overall survival. Recent improvements in prenatal detection are a milestone in affording time for re-assessments and parental counselling. The true benefit of antenatal therapy is circumscribed and should be offered only in selected cases of isolated severe CDH as defined by existing guidelines. Postnatal intensive respiratory supportive therapy and innovative surgical techniques within specialized tertiary centres has had a major impact on survival of babies with CDH.

CONCLUSION

The high survival of 'selected cases' that are live births and benefit from optimal care will be difficult to improve by antenatal interventions. The multidisciplinary approach to basic research and randomized clinical trials will further define the best approach to the foetus and neonate with CDH.

Factors associated with survival in infants with congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation: a report from the Congenital Diaphragmatic Hernia Study Group

OBJECTIVE

To identify factors associated with survival in patients with congenital diaphragmatic hernia (CDH) treated with extracorporeal membrane oxygenation (ECMO).

METHODS

We retrospectively analyzed the data on 3100 patients with CDH in the Congenital Diaphragmatic Hernia Study Group from 82 participating pediatric surgical centers (1995-2004). Covariates considered included prenatal and perinatal clinical information, specifics of surgical repair, and the duration of extracorporeal support.

RESULT

Nine hundred seven patients from the registry were identified as having been both managed with ECMO and undergone attempted surgical repair. The survival rate for the entire Congenital Diaphragmatic Hernia Study Group registry was 67% and 61% for those receiving ECMO in whom repair was attempted (P < .001). Among ECMO-treated children, survivors had a greater estimated gestational age (38 +/- 2 vs 37 +/- 2 weeks; P < .01), greater birth weights (3.2 +/- 0.5 vs 2.9 +/- 0.5 kg; P < .001), were less often prenatally diagnosed (53% vs 63%; P < .01), and were on ECMO for a shorter period of time (9 +/- 5 vs 12 +/- 5 days; P < .001). In logistic regression models, therapy-related variables, including the duration of ECMO, the nature of diaphragmatic repair, and the type of abdominal closure and certain comorbidities, particularly the presence of a concomitant severe cardiac abnormality, were independently associated with outcome.

CONCLUSION

Our model identifies a group of pre-surgical and postsurgical parameters that predict survival rate in patients with CDH on ECMO support. This model was derived from the retrospective data from a large database and will need to be prospectively tested.

Value of prenatal magnetic resonance imaging in the prediction of postnatal outcome in fetuses with diaphragmatic hernia

OBJECTIVES

To investigate the potential value of antenatally determined total fetal lung volume (TFLV) by magnetic resonance imaging (MRI) in the prediction of the postnatal survival in congenital diaphragmatic hernia (CDH).

METHODS

We examined fetuses with isolated CDH, in which MRI was used at 22-38 weeks of gestation to measure TFLV and assess intrathoracic herniation of abdominal viscera, that were liveborn after 30 weeks of gestation and had postnatal follow-up until death or discharge from hospital. Regression analysis was used to investigate the effect on survival of gestational age at diagnosis, observed to expected (o/e) TFLV, intrathoracic herniation of the liver, side of CDH, gestational age at MRI, institution, year and gestational age at delivery. In 76 fetuses measurements of o/e TFLV and the lung area to head circumference ratio (LHR) were performed within 2 weeks of each other; in these cases o/e TFLV and o/e LHR were compared for their prediction of postnatal survival.

RESULTS

In the 148 cases that fulfilled the entry criteria, multiple regression analysis demonstrated that significant predictors of survival were the presence or absence of intrathoracic herniation of the liver and o/e TFLV. The area under the receiver-operating characteristics curves for prediction of postnatal survival from o/e TFLV was 0.786 (standard error, 0.059; P < 0.001) and that from o/e LHR was 0.743 (standard error, 0.069; P = 0.001).

CONCLUSIONS

In the assessment of fetuses with CDH, MRI-based o/e TFLV is useful in the prediction of postnatal survival.

Prenatal prediction of survival in isolated diaphragmatic hernia using observed to expected total fetal lung volume determined by magnetic resonance imaging based on either gestational age or fetal body volume

OBJECTIVES

To compare the predictive value of the prenatal observed to expected (o/e) lung volume as measured by fetal magnetic resonance imaging (MRI), based on an algorithm using either the gestational age or fetal body volume (FBV), for neonatal survival of fetuses with isolated congenital diaphragmatic hernia (CDH).

METHODS

We included 53 fetuses with a prenatal diagnosis of isolated CDH, 26 without and 27 with prenatal tracheal occlusion, who were assessed by fetal MRI, liveborn after 32 weeks, and in whom follow-up until discharge from the neonatal care unit was available. Measurements of lung volumes were expressed as a percentage of the appropriate mean (o/e total fetal lung volume (TFLV) x 100) either for gestational age or for FBV. Measurements of FBV were expressed as a percentage of the appropriate mean (o/e FBV x 100) for gestation. Fetuses with prenatal intervention were all assessed > or = 24 h after balloon removal. Regression analysis was used to examine the effect on postnatal survival of either o/e TFLV based on gestational age or based on FBV, gestation at delivery, side of CDH, intrathoracic position of the liver and prenatal intervention. Receiver-operating characteristics (ROC) curves were constructed for the prediction of survival by o/e TFLV based on gestational age and o/e TFLV based on FBV, for all fetuses, as well as for those with o/e FBV between 90 and 110% and those with values beyond that range. A power calculation for the number of fetuses needed to show a difference between the ROC curves was performed.

RESULTS

Regression analysis demonstrated that o/e TFLV based on gestational age and on FBV were the only independent predictors of postnatal survival. The area under the ROC curve for prediction of postnatal survival from the o/e TFLV based on gestational age was 0.811, and for that based on FBV it was 0.868 (P < 0.001 for both). For fetuses with o/e FBV between 90 and 110%, and those with values < 90% and > 110%, the area for measurements based on gestational age was 0.895 and 0.733, respectively; when based on FBV it was 0.906 and 0.833 (P < 0.01 for all). A minimum of 273 patients would be needed to provide a probability of 90% of detecting a difference between the areas under both ROC curves.

CONCLUSIONS

In fetuses with isolated CDH, lung volume as measured by fetal MRI was significantly correlated with survival. Prediction tended to be better by o/e TFLV based on FBV rather than gestational age. The difference in the prediction of survival between o/e TFLV based on FBV or gestational age was dependent on fetal biometry.

Quantification of intrathoracic liver herniation by magnetic resonance imaging and prediction of postnatal survival in fetuses with congenital diaphragmatic hernia

OBJECTIVE

To quantify the degree of intrathoracic liver herniation by magnetic resonance imaging (MRI) and evaluate its effect on postnatal survival in fetuses with isolated congenital diaphragmatic hernia (CDH).

METHODS

Forty fetuses that were expectantly managed and that were delivered after 32 weeks' gestation were included in this study. On axial T2 weighted MR images the degree of intrathoracic liver herniation was measured by volumetry, using the xyphoid process and thoracic apex as landmarks. The ratio of the volume of the liver that was herniated into the thoracic cavity to the volume of the thoracic cavity was calculated (LiTR). All the fetuses also underwent lung volumetry, and the ratio of the observed/expected total fetal lung volume (o/e TFLV) was calculated. Regression analysis was used to investigate the effect on survival of side of occurrence of CDH, o/e TFLV, LiTR and gestational age at delivery. Receiver-operating characteristics (ROC) curves were constructed to examine the prediction of survival by o/e TFLV or LiTR alone and o/e TFLV and LiTR together.

RESULTS

Univariate regression analysis demonstrated that significant predictors of survival were o/e TFLV and LiTR. Multiple regression analysis demonstrated that o/e TFLV and LiTR provided independent prediction of survival. The area under the ROC curve (AUC) for the prediction of postnatal survival from o/e TFLV alone was 0.846 (P < 0.001; SE = 0.062) and the AUC from LiTR alone was 0.875 (P = 0.001; SE = 0.072). The AUC for the prediction of postnatal survival from o/e TFLV and LiTR combined was 0.912 (P < 0.001; SE = 0.045), however it was not statistically significantly different from that of o/e TFLV alone.

CONCLUSION

In expectantly managed CDH fetuses, assessment of LiTR using MRI provided prediction of postnatal survival independently from o/e TFLV.

Prenatal ultrasound and fetal MRI: the comparative value of each modality in prenatal diagnosis

Fetal MRI is used with increasing frequency as an adjunct to ultrasound (US) in prenatal diagnosis. In this review, we discuss the relative value of both prenatal US and MRI in evaluating fetal and extra-fetal structures for a variety of clinical indications. Advantages and disadvantages of each imaging modality are addressed. In summary, MRI has advantages in demonstrating pathology of the brain, lungs, complex syndromes, and conditions associated with reduction of amniotic fluid. At present, US is the imaging method of choice during the first trimester, and in the diagnosis of cardiovascular abnormalities, as well as for screening. In some conditions, such as late gestational age, increased maternal body mass index, skeletal dysplasia, and metabolic disease, neither imaging method may provide sufficient diagnostic information.

The lung-to-thorax transverse area ratio at term and near term correlates with survival in isolated congenital diaphragmatic hernia

OBJECTIVE

The purpose of this study was to determine how well liver position, the lung area-to-head circumference (L/H) ratio, and the lung-to-thorax transverse area (L/T) ratio predicted the need for extra-corporeal membrane oxygenation (ECMO) and survival in fetuses with isolated congenital diaphragmatic hernia (CDH).

METHODS

Antenatal records of 25 fetuses with isolated left-sided CDH who were born by cesarean delivery under fetal stabilization at this institution were reviewed. The latest determinations of the L/H and L/T ratios before birth (between 34 and 38 weeks' gestation) were compared on the basis of the cutoff points for mortality: less than 1.0 versus 1.0 or greater for the L/H ratio and 0.08 or less versus greater than 0.08 for the L/T ratio. Outcome measures assessed were survival (discharge to home) and the need for ECMO.

RESULTS

Overall survival was 64% (16/25). Postnatal survival in fetuses with an L/T ratio of 0.08 or less was statistically lower than in those with an L/T ratio of greater than 0.08 (33% versus 81%; P = .0308). The percentage requiring ECMO in the group with an L/T ratio of 0.08 or less was also higher than that of the group with an L/T ratio of greater than 0.08, but the difference was not statistically significant (67% versus 25%; P = .0872). Neither the L/H ratio nor herniation of the fetal liver into the chest affected survival or the need for ECMO.

CONCLUSIONS

In fetuses with isolated CDH at term or near term, the L/T ratio may be a better predictor of outcome than the L/H ratio or liver herniation.

Timing of lung size assessment in the prediction of survival in fetuses with diaphragmatic hernia

OBJECTIVES

To investigate whether the prediction of postnatal outcome of fetuses with isolated congenital diaphragmatic hernia depends on the gestational age at assessment using the fetal observed to expected (O/E) lung area to head circumference ratio (LHR), by comparing the performance of the test at 22-23 weeks with that at 32-33 weeks of gestation.

METHODS

Following prenatal diagnosis of isolated diaphragmatic hernia before 22 weeks, we evaluated the O/E LHR at 22-32 weeks and again at 32-33 weeks of gestation. Only cases liveborn beyond 34 weeks of gestation and with postnatal follow-up available until discharge from the hospital were included. Regression analysis was used to examine the effect on postnatal survival of O/E LHR, gestational age at delivery, side of the diaphragmatic hernia and intrathoracic position of the liver. Wilcoxon rank test for paired samples was used to compare median O/E LHR at 22-23 weeks and 32-33 weeks, in babies who survived and in those who died. Receiver-operating characteristics (ROC) curves were constructed for the prediction of survival by O/E LHR at 22-23 weeks and at 32-33 weeks.

RESULTS

In total, 53 pairs of measurements could be assessed. Univariate logistic regression analysis demonstrated that significant predictors of survival were the presence or absence of intrathoracic herniation of the liver, the O/E LHR at 22-23 weeks and the O/E LHR at 32-33 weeks of gestation. Multivariate logistic regression analysis demonstrated that only O/E LHR at 22-23 weeks or 32-33 weeks provided significant independent prediction of survival. The median O/E LHR at 22-23 weeks was not significantly different from that at 32-23 weeks either in survivors or in babies that subsequently died in the neonatal period (P = 0.25 and P = 0.09, respectively). The area under the ROC curve for prediction of postnatal survival from the O/E LHR at 22-23 weeks was 0.789 (P < 0.001) and that for prediction from the O/E LHR at 32-33 weeks was 0.842 (P < 0.001).

CONCLUSIONS

In isolated diaphragmatic hernia, O/E LHR measurement at 22-23 weeks as well as at 32-33 weeks provides useful independent prediction of subsequent survival. The prediction of postnatal survival using O/E LHR is independent of the timing of assessment.