GDF15 and hydrops fetalis: Although natriuretic peptides and cardiac troponins are currently the most widely employed biomarkers for the prognosis and diagnosis of HF, next-generation biomarkers, including soluble source of tumorigenicity 2 (sST2), proenkephalin, growth differentiation factor-15 (GDF-15), and galectin-3 (Gal-3) have also been well-established as promising biomarkers for HF diagnosis and prognosis [128,129].