Mass. Gen. Laws ch. 111, § 5J

Any person who administers radiation treatment of any kind to another person shall use lead shields to protect such other person when clinically appropriate. If such other person is a female, any person who so administers such radiation treatment shall inform her that radiation can be hazardous to an unborn child, shall inquire whether such female believes she is pregnant, and if the answer is affirmative, take clinically appropriate precautions before administering such treatment.