X-rays can harm an unborn baby. If a baby receives more than 5,000 millirads (5 rads) of radiation from X-rays before birth, the baby might have birth defects. The X-rays might affect the baby's genes or 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. The baby is at most risk between weeks 8 and 15 of the pregnancy.
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 when you had 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.
Magnetic resonance imaging (MRI's) does not use radiation.
Ask your healthcare provider any questions you have about the use of X-rays during pregnancy.