Maximum permissible radiation dose in pregnancy is –

Maximum permissible dose in pregnancy is 5 mSv (0.5 rem).  Rem = Rad x Quality factor. Main radiation exposure during pregnancy can be by X-rays (radiography or CT), and the quality factor of X-rays is 1.  That means Rem = Rad. Therefore, the maximum permissible dose in pregnancy is 0.5 rem or 0.5 rad.