IMPA2 and hydrops fetalis: In the MR analysis between differentially expressed genes and HF, BCL2, IFI44L, ISG15, and COLGALT2 were associated with an increased risk of HF, whereas the remaining six genes, including ENPP4, CLSTN3, IMPA2, CNTRL, DNAJC10, and GOLGA8B, were associated with a protective effect against the occurrence of HF.