NPPB and hydrops fetalis: Renin levels showed no relationship with HF severity reflected by NT-proBNP (ρ = −0.05, p = 0.273) and NYHA groups (NYHA I: 133.7 μIU/ml (Q1–Q3: 29.6–498.3) vs. NYHA II: 127.9 μIU/ml (Q1–Q3: 23.9–644.9) vs. NYHA III/III+: 122.7 μIU/ml (Q1–Q3: 31.9–618.8), p = 0.753) (Figure 2(a)).