NPPB and hydrops fetalis: The most common clinically relevant parameters for the evaluation of the severity of HF with reduced ejection fraction (HFrEF) are the (i) left ventricular ejection fraction (EF), (ii) plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) level and (iii) functionally, the New York Heart Association (NYHA) classification [1,2].