Nowadays, many pregnant mothers have X-rays, CTs or accompany family members into the examination room without their knowledge. The fear is that it may cause malformations. Here are some detailed answers to such questions. 1, first of all, we need to clarify a problem X ray, CT does have radiation, will also cause harm to the body, the fetus, but this will take into account a “quantity” of the problem. 2, then we do a CT, the amount of radiation X ray is how much? For example, the maximum radiation dose of abdominopelvic CT is 34mSv. A head CT is 2mSv (a head CT will cover the pregnant woman’s abdomen with a lead suit, so the radiation dose to the fetus is very low.) ー a chest CT is 8mSv 3, that do an X-ray dose, the amount of radiation is to less? For example: the radiation dose of an ordinary chest X-ray is 0.02mSv a knee X-ray is 0.005mSv a CT of the head is 2mSv 4, how much dose will affect the fetus? 0-2 weeks of gestation: (i.e. last menstruation-14 days) The threshold of teratogenic dose is 50-100mSv, the main effect is fetal miscarriage and embryonic abortion. 2-8 weeks of gestation: the threshold of teratogenic dose is 200mSv, which mainly affects fetal congenital malformations (neurological development of the brain) 8-15 weeks of gestation: the threshold of teratogenic dose is 60-310mSv, which mainly affects mental development and malformations. So for reaching 50mSv, at least 2000 times for X-rays, 2 times for CT abdominal, several times for head, chest. 5, MRI he is a magnetic field, pregnant women this is possible to do, there is no radiation. In summary: In summary: If we accidentally contact CT, X-rays, rather than to check, can not need to worry so much about the baby will cause deformities, if we even check if the dose is not reached will not cause much impact. Wisdom: X-rays, CT or radiation, non-essential examination during pregnancy, try to avoid it there to avoid, the theory is just a theory, each person’s situation is different, each person’s tolerance level for radiation is different, metabolism is also different, in pregnancy to pay special attention.