Fetuses with hydatid cystic aneurysm are generally not recommended because of the high morbidity and mortality rate of this condition, and even if surgery is performed, the prognosis is poor. Fetal hydatid cysts are mostly related to chromosomal abnormalities, and are caused by abnormal development of the lymphatic system, which is also a manifestation of fetal developmental abnormalities. If a fetal hydatid cystoma is found during pregnancy, and the tumor is relatively small, it can be left untreated for the time being, because this hydatid cystoma may absorb on its own, so it can be reviewed regularly first. If the hydatid cyst is found to be gradually increasing in size, amniocentesis or cord blood sampling is recommended to determine whether the fetus has any chromosomal abnormality, i.e. prenatal diagnosis is needed. If the prenatal diagnosis determines that the fetus has a chromosomal abnormality, then the pregnancy should be terminated promptly, i.e., induction of labor.