NPPB and hydrops fetalis: Although brain natriuretic peptide (BNP) was identified as a key biomarker in predicting new‐onset HF in the Framingham Heart Study (FHS),19 and while natriuretic peptide levels increase in proportion to the severity of cardiac dysfunction,20 the association between BNP and HF is confounded by obesity (levels are reduced) and renal impairment (levels are increased).