NPPB and hydrops fetalis: Control 14.02 pg/mL ± 7.57, n = 22; HF NT-proBNP < 500 pg/mL 19.06 pg/mL ± 8.51, n = 11; HF NT-proBNP ≥500 pg/mL 41.81 pg/mL ± 30.55, n = 6).