CT uses ionizing radiation from X-rays to complete the examination, and X-rays have a certain effect on the human body. In early pregnancy, fetal organs are still developing and are more sensitive to X-rays, which may affect their development, leading to fetal malformations, developmental restrictions, and in severe cases, may also lead to the death of the embryo.The effects of X-rays are usually related to the gestational week of pregnancy, if it is in the early stages of pregnancy, 1-14 days of X-rays have a relatively small impact; if the pregnant woman is pregnant for more than 14 days, X-rays should be avoided as much as possible. In addition, the effects of X-rays on the fetus are more severe in the 2-4 week period, when the brain and other important organs are taking shape. Of course, during a woman’s pregnancy, if it is very necessary to perform a CT examination, it can be done under the protection of a lead suit. In non-essential cases, CT examinations are to be avoided or replaced by ultrasound as well as MRI.