Rate of increase of lung-to-head ratio over the course of gestation is predictive of survival in left-sided congenital diaphragmatic hernia

Clinical assessment of the fetal right Quantitative Lung Index

OBJECTIVES

We have previously described gestational-age-independent sonographic indices to assess fetal lung size in the right and left lungs: The Quantitative Lung Index for the right lung (QLI-R) and for the left lung (QLI-L), respectively. The purpose of this study was to evaluate the clinical cutoff point of the QLI-R to predict pulmonary hypoplasia and neonatal death.

MATERIALS AND METHODS

Retrospective assessment of the QLI-R in patients with left-sided congenital diaphragmatic hernia (CDH-L) and other fetal conditions at risk for fetal pulmonary hypoplasia. Cross-section and longitudinal assessment of the behavior of the QLI-R in untreated and treated patients. ROC curve analysis to determine the optimal cutoff point of the QLI-R in predicting neonatal death.

RESULTS

One hundred eighteen patients with CDH-L and other fetal conditions at risk for pulmonary hypoplasia had QLI-R measurements done. Seventeen patients were excluded for various reasons. Eleven patients with conditions other than CDH-L but at risk for pulmonary hypoplasia were used for intraclass coefficient measurements of the QLI-R. Ninety patients had CDH-L, of which 78 did not undergo antenatal intervention and in which the cutoff point for pulmonary hypoplasia and neonatal demise was assessed. Stent tracheal occlusion was performed in the remaining 12 patients with CDH-L, in which the behavior of the QLI after surgery was assessed. Analysis of the ICC showed an overall intra-rater reliability of 0.985 (Cronbach's Alpha-based). There was no correlation between gestational age and QLI-R (-0.73, Pearson correlation, p = .72). Twenty-six of the 78 patients (33%) with CDH-L managed expectantly had a neonatal demise. A QLI-R equal to or less than 0.45 was significantly predictive of neonatal demise (area under the curve 0.64, p = .046, sensitivity 77%). Nine of the 12 patients (75%) that underwent tracheal occlusion had neonatal survival. Of these, 10 had serial assessments of the QLI-R after surgery. An increase in the QLI-R of 0.11 was associated with a tendency for neonatal survival (p = .056).

CONCLUSION

Our study confirms that the QLI-R is a gestational-age-independent measurement of fetal lung size, with a high degree of reproducibility. In a population of expectantly managed CDH-L patients, a cutoff value of the QLI-R of 0.45 or lower is predictive of neonatal death from pulmonary hypoplasia. The QLI-R can be used to monitor fetal lung growth after tracheal occlusion, and an increase in the QLI-R is suggestive of neonatal survival. Further prospective studies are needed to confirm these findings and to explore the use of the QLI in other populations at risk for pulmonary hypoplasia and consequent neonatal demise.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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