It is classed as a category C, meaning...if the benefits outweigh the risks, doctors do prescribe Tylenol 3 during pregnancy. As long as you are taking prescribed doses and only for a short amount of time, more than likely, everything will be fine. Not POSITIVELY...but most-likely. The risks increase further along in third trimester as birth approaches. If there are significant amounts of opiods taken close to birth, it could cause infant dependency and withdrawal and respiratory depression. If you feel it is necessary to take T3, my suggestion would be a low dose as needed, and not for more than a few days, based on what I have read. Your doctor can tell you best.