CoDE-HF with BNP and MR-proANP identified 30% and 48% as low-probability [NPV of 98.5% (97.1–99.3%) and 98.5% (97.7–99.0%)], and 30% and 28% as high-probability [PPV of 78.6% (70.4–85.0%) and 75.1% (70.9–78.9%)], respectively, and performed consistently across subgroups. The gene discussed is NPPB; the disease is hydrops fetalis.