If you are pregnant or breast-feeding, ask your doctor or nurse before taking any medication (OTC or prescription). It is especially important not to use aspirin, ibuprofen, or naproxen sodium during the last three months of pregnancy unless directed to do so by a doctor, because these medicines may cause problems in the unborn child, or complications during delivery.
Acetaminophen has not been shown to cause birth defects or other problems in laboratory studies. However, to be on the safe side, talk to your doctor before taking any OTC medications during pregnancy.
Laboratory studies have found that aspirin can cause birth defects in animals. Do not take aspirin during the last three months of pregnancy unless your doctor has ordered it. Some reports have suggested that too much aspirin use late in pregnancy may cause a decrease in the newborn's weight and possible death of the fetus or newborn infant. However, the mothers in these reports had been taking much larger amounts of aspirin than are usually recommended.
Studies of mothers taking aspirin in the doses that are usually recommended did not show these unwanted effects, but there is a chance that regular use of aspirin late in pregnancy may cause unwanted effects on the heart or blood flow of the fetus and newborn infant. Use of aspirin during the last two weeks of pregnancy may cause bleeding problems in the fetus before or during delivery, or in the newborn infant. Also, too much use of aspirin during the last three months of pregnancy may increase the length of pregnancy, prolong labor, cause other problems during delivery, or cause severe bleeding in the mother before, during, or after delivery.
Ibuprofen and Naproxen Sodium
FDA-approved labeling for both ibuprofen products and naproxen sodium products contain the same warning, which states that women should not take these medications during the last three months of pregnancy (unless directed to do so by a doctor), because they may cause problems in the unborn child or complications during delivery.