GDF15 and hydrops fetalis: Compared to controls, patients with HF had higher median values of NT-proBNP (16,216 [interquartile range, IQR = 27739] vs. 2883 [5866] pg/mL, p < 0.001), GDF-15 (7512 [7084] vs. 6005 [4892] pg/mL, p = 0.014), but not cNEP (315 [107] vs. 318 [124] pg/mL, p = 0.818).