NPPB and hydrops fetalis: In our cohort, NT-proBNP concentrations demonstrated a stepwise increase across HF subtypes, with the highest levels observed in HFrEF patients and progressively lower values in HFmrEF and HFpEF, reinforcing the inverse relationship between NT-proBNP and systolic function and consistency with prior studies demonstrating higher biomarker levels in patients with reduced EF [16].