BCR and hydrops fetalis: In Fig 3, the AHF subgroup demonstrated that the increase of BCR level was potentially relevant to a higher risk of all-cause mortality in patients with HF (HR = 1.79, 95% CI 1.15–2.79; I2 = 93.9%, P = 0.000) as did the non-AHF subgroup (HR = 1.51, 95% CI 1.34–1.71; I2 = 37.1%, P = 0.122).