Integrated Prenatal Cardiopulmonary Assessment Using Fetal Echocardiography in Isolated Left‐Sided Congenital Diaphragmatic Hernia

Objective Prenatal severity assessment in congenital diaphragmatic hernia (CDH) primarily relies on lung‐based parameters such as the observed‐to‐expected lung‐to‐head ratio (o/eLHR) and liver position; however, these markers do not fully reflect fetal cardiopulmonary adaptation. We investigated the prognostic significance of fetal echocardiographic parameters and integrated these in prenatal prediction models in left‐sided CDH. Methods This nationwide multicenter retrospective study included fetuses with prenatally diagnosed isolated left‐sided CDH. Gestational age‐adjusted Z‐scores were generated for fetal cardiac dimensions. Receiver operating characteristic analyses were performed to evaluate prognostic performance for survival. Results A total of 363 fetuses were included, with an overall survival rate of 74.9%. Non‐survivors demonstrated significantly smaller right pulmonary artery and mitral valve dimensions than survivors. Among fetal echocardiographic parameters, the mitral‐to‐tricuspid valve ratio (MTR) demonstrated the strongest predictive performance, with an area under the curve (AUC) of 0.77. In fetuses evaluated at ≤ 29 weeks’ gestation, an exploratory model combining MTR with o/eLHR and liver‐up status achieved an apparent AUC of 0.827. Conclusion Fetal echocardiographic parameters were associated with survival in CDH. Integrated prenatal cardiopulmonary assessment incorporating MTR may provide complementary prognostic information although independent external validation is required.