OC16.07: Prediction of survival in congenital diaphragmatic hernia fetuses: which method is better using observed/expected total fetal lung volumes?

Congenital diaphragmatic hernia (CDH) fetuses can experience changes in their biometrics as the result of the anomaly. This could lead into a discrepancy between gestational age (GA) and fetal size at the time of imaging that could have an impact calculating Observed/Expected Total Fetal Lung Volume (O/E TFLV). The aim was to compare the prediction of O/E TFLV for 6-month survival in left-sided CDH fetuses between TFLV normalised by GA using first trimester Crown–Rump Length (CRL) vs using fetal size determined-GA at the time of MRI. Retrospective cohort study of fetuses with isolated left-sided CDH. O/E TFLV was calculated using GA based on CRL or fetal size-determined GA at the time of MRI. Severe CDH was defined if O/E TFLV was <32% and liver herniation >21%. Prediction of survival was evaluated using ROC and their areas under the curves (AUCs) and logistic regression analyses adjusting by CDH severity and liver herniation. 105 fetuses had MRI during the third trimester (≥29 weeks), 85 of them were also evaluated during the second trimester (20-28.6 weeks). 30/105(28.6%) presented with severe CDH. 86/105(80.9%) were alive at 6 months of life. Surviving infants showed significantly higher O/E TFLV than their non-surviving counterparts regardless of the method to calculate O/E TFLV (see figure 1). Higher O/E TFLV based on CRL or fetal size at MRI were associated with higher chances of survival regardless of the timing of assessment (see figure 1). No differences were observed in the AUCs for prediction of survival using O/E TFLV based on CRL or fetal size (see figure 1). There were no differences in the prediction of survival in isolated left-sided CDH fetuses using O/E TFLV based on GA obtained by CRL or using fetal size-GA at the time of MRI. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.