PTGS1 and hydrops fetalis: Given that there is a significant increase of gene Ephx2 induced by HF or DEX (Table 1), that arachidonic acid metabolism is a significant related KEGG pathway in the HF model, and that arachidonic acid metabolites play important roles on BP control [15], we analyzed 4 upregulated genes (Ephx2, Hpgds, Ptgds, and Ptgs1) in arachidonic acid metabolism pathway.