NPPB and hydrops fetalis: A greater number of abnormal pulmonary vascular measures was associated with progressively higher circulating NT-proBNP levels (S4A Fig) and greater incidence of HF (adjusted hazard ratio relative to no abnormalities: 1.8 [95% CI 1.2–2.8, p = 0.007] for one abnormality; 1.8 [1.0–3.3, p = 0.07] for two abnormalities; 4.0 [1.9–8.3, p < 0.001] for three abnormalities; p for trend < 0.001 [95% CI 1.2–1.9]; S4B Fig).