According to Drugs.com, pregnant women should not use Tylenol Cold without their doctor's advice. It is unknown whether or not this medication could harm an unborn baby.
Tylenol Cold contains acetaminophen, dextromethorphan, guaifenesin and phenylephrine. This medication is under the N pregnancy category of the Food and Drug Administration (FDA), meaning that it has not been assigned a category.
Both dextromethorphan and guaifenesin have been individually assigned to FDA pregnancy category C. This means that studies in animal reproduction have shown there is an adverse effect on a fetus but that there are no well-controlled human studies.
These medications may also pass into breast milk. Tylenol Cold should not be used during breast-feeding without a doctor's advice.