Pregnant women are very worried about taking X-rays and often take X-rays without knowing they are pregnant. They were concerned about the safety of fetal radiation and demanded abortion. is it necessary? careful! Radiation Dosage Embryos exposed to ionizing radiation may cause embryonic death, miscarriage, fetal congenital malformations, mental retardation, cerebellar disease, and fetal growth retardation. These embryonic injuries are mainly related to radiation dose and embryonic development stage.