1.What is X-Ray?
X-Rays are basically electro-magnetic radiations used for visualizing those structures in the body which are not seen from outside.
Yes. After a particular dose they are harmful. Hence X-Rays should not be done repeatedly (unless of course indicated)
X-Rays are taken to visualize the bones, soft tissues. Air in lungs, air in barrel and to identify any pathology.
Usually during the first trimerters (1-13 weeks), X-Rays should be avoided as it is harmful to the foetus. But if it is medically indicated then can be done in proper lead protection to pregnant lady and foetus.
Hence women undergoing X-Ray should inform the technician about her pregnancy before hand.