Hi bubbles - the reason that women who need an x-ray are asked beforehand if they are, or could be pregnant, is because the rays are known to destroy the genetic information in cells, and can cause mutations and low birth weights. They effect rapidly dividing cells - such as in your hair - and in a foetus. If a person needed to have an x-ray done on their arm or leg, lead shields'd be put across the abdomen to give protection, but some people think that one quick exposure to radiation won't cause any harm at all, & that it's just repeated doses that does it. If you're about to have an x-ray & are, or could be pregnant, have a word with the radiologist first.