NPPB and hydrops fetalis: Multiple studies have demonstrated that NT-proBNP concentrations have a high negative predictive value (94–99%) for excluding HF in acute (BNP <100 pg ml−1 or NT-proBNP <300 pg ml−1) and non-acute (BNP <35 pg ml−1 or NT-proBNP <125 pg ml−1) settings.13