IL6 and hydrops fetalis: There is a need to delineate how HS modulates key HF-related pathways and biomarkers, including oxidative stress and proinflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and C-C motif chemokine ligand 20 (CCL20), as well as brain natriuretic peptide (BNP) and endothelin-1 (ET-1) [18,21,31,32,33].