In terms of mechanism, we confirmed that circCREBBP, as a miRNA sponge, binds to hsa-miR-1291 and regulates the expression of left-right determinant cluster 2 (LEFTY2), revealing that circCREBBP/ha-miR-1291/LEFTY2 axis plays a key role in HSCs activation and HF. This evidence concerns the gene LEFTY2 and hydrops fetalis.