X-rays can harm an unborn baby. If a baby receives more than 10,000 millirads of radiation from x-rays before birth, the baby might have birth defects. The x-rays might cause leukemia. Most x-rays give much smaller doses of radiation than this. For example, during an x-ray of the legs, only 1 millirad is absorbed.
Although only a small amount of radiation may be absorbed, x-rays should be avoided, especially in early pregnancy. This is why x-ray technologists may ask you about your last menstrual period before taking an x-ray. X-ray studies are done during pregnancy only in urgent cases. For example, you may have an x-ray if you have a broken bone, to check for pneumonia, or to look for kidney stones.
When taking an x-ray, the technologist should put a lead apron over you to protect the baby. However, this may not be possible if the apron will interfere with the necessary views (for example, x-rays of the chest).
Ultrasound machines do not use radiation. Often an ultrasound scan can be done instead of an x-ray.
Ask your health care provider any questions you have about the use of x-rays during pregnancy.