Fetal hemangioma 5 cm is relatively large and may compress the corresponding organs, which in turn may affect the normal development of the fetus. There are many factors causing fetal hemangioma, which may be caused by abnormal endothelial proliferation of blood vessels and abnormal tissue differentiation during the embryonic development of the fetus in the mother, resulting in structural mismatch of the controlling genes. It may also be caused by the exposure of the pregnant woman to a large amount of radiation in the course of pregnancy. It may also be caused by long-term exposure to chemicals, etc. during pregnancy. During pregnancy, pregnant women should avoid contact with chemical substances or pollutants, etc. If fetal hemangioma is found, it is recommended to go to the hospital for a comprehensive examination, so as to make a clear diagnosis and carry out timely diagnosis and treatment.