I'm wondering, concretely, what are the risks for a fetus if the mother takes a cough syrup "not recommended for pregnant women"?

Taking a cough syrup that is not recommended for pregnant women can have different risks for the fetus depending on the specific ingredients in the syrup. While some cough syrups containing ingredients like dextromethorphan, menthol, and guaifenesin are generally considered safe during pregnancy, others with ingredients like pseudoephedrine may be associated with an increased risk of certain birth defects. It is important to consult with a healthcare provider before taking any medication while pregnant to ensure the safety of both the mother and the baby.