Fetal subcutaneous edema usually can not be well, it may be immune fetal edema, or non-immune fetal edema, that is, chromosomal abnormalities, genetic diseases, congenital malformations and other factors caused. 1. Immune fetal edema: immune fetal edema is mainly caused by incompatibility of blood type between mother and fetus, such as mother’s blood type O and fetus’s blood type O. Antibodies in the mother’s blood enter into the fetus’s body through the placenta and have antagonistic effect on the red blood cells, which makes the fetus develop ABO hemolysis and leads to fetal edema. 2. Non-immune fetal edema: (1) chromosomal abnormalities: chromosomal defects can also lead to fetal subcutaneous tissue edema, the common ones are 21-trisomy syndrome, 18-trisomy syndrome and X monosomy. (2) Hereditary diseases: inborn metabolic abnormalities such as glycogen storage disease and mucopolysaccharide storage disease will lead to enlargement of liver and spleen and obstruction of venous blood return, which will eventually lead to generalized subcutaneous edema of the fetus. (3) Congenital anomalies: if the fetus has congenital cardiac anomalies such as cardiac hypoplasia, due to the abnormal heart function, it will lead to the reduction of the effective circulating blood volume of the fetus, which will lead to the sodium retention and venous stagnation, and subcutaneous edema will also occur. Fetal subcutaneous edema usually can not be good, need to be actively examined to clarify the cause, if it is caused by chromosomal and genetic abnormalities, should consider termination of pregnancy.