IDH2 and hydrops fetalis: In detail, in the comparison between XF and HF (p < 0.05; Figure 7A, Tables S12 and S13), four differential metabolites—oxidized glutathione, arachidonic acid, prostaglandin E2, and 5’AMP—involved in FA metabolism, were significantly associated with several key genes, including LAP3, GPX1, PGD, SAT1, ACSL4, and IDH2.