O/E LHR and O/E FLV as predictors for chronic lung disease in infants with congenital diaphragmatic hernia

Aims: Prenatal measurement of the observed-to-expected lung-to-head ratio (O/E LHR) and the observed-to-expected fetal lung volume (O/E FLV) may be useful in predicting mortality in patients with congenital diaphragmatic hernia (CDH). Prenatal measurements to predict pulmonary morbidity, such as chronic lung disease (CLD), are lacking.

Objective: To determine if O/E FLV and O/E LHR are useful prenatal predictors of CLD in infants with CDH.

Methods: Newborns with CDH born between 2002 and 2007 were eligible for inclusion. Data on survival, pulmonary status and basic patient characteristics were collected. CLD, defined as oxygen dependency at day 28, was the primary endpoint. Univariate analyses and multivariate analyses were performed. Predictive values of the O/E LHR and O/E FLV were determined by ROC-curves. An area under the curve (AUC) of >0.8 was considered a good predictor.

Results: 102 infants with CDH were included. The incidence of CLD was 59% (n=60). Median O/E FLV was 25.7 (range 3.8–52.8) in CLD patients and 35.7 (range 14.3–76.1) in non-CLD patients (P<0.0001). Median O/E LHR was 47.6 (range 25.6–98.0) in CLD-patients and 51.9 (range 25.6–96.9) in non-CLD patients (p=0.026). Liver position and gestational age were significant in the multivariate analysis. ROC-curves of the O/E LHR and O/E FLV showed an AUC of 0.81 and 0.83, respectively.

Conclusion: This study shows that the O/E FLV was a slightly better predictor than the O/E LHR. Clinical relevance of this difference is doubtful. To determine predictors for pulmonary morbidity, cooperation between centers and centralization of care is needed to conduct further research in prenatal imaging in infants with CDH.

Lung-to-head ratio - chronic lung disease - congenital diaphragmatic hernia - fetal lung volume