Women who are pregnant or nursing are advised to be cautious in their use of headache medications. For example, studies have indicated that aspirin may cause birth defects in humans. As a result, it is recommended that pregnant women not use aspirin. Aspirin also passes into breast milk and should not be taken by women who are breastfeeding unless recommended by a physician.

Studies on whether or not ibuprofen and acetaminophen cause birth defects in humans have not been performed. However, it is possible that ibuprofen may cause undesirable effects on the heart or blood flow of the fetus when taken by the mother during the last few months of pregnancy. To date, there are no indications linking the use of acetaminophen during pregnancy with birth defects. Nonetheless, pregnant women should take ibuprofen or acetaminophen only in close consultation with a physician.

It is not known whether ibuprofen passes into breast milk. Acetaminophen does pass into breast milk, but only in low levels that do not appear to hurt infants of mothers who breastfeed. Breastfeeding mothers are urged to consult a physician before using these headache medications.

In addition, other medications that may be used to treat headaches may be unsuitable for women who are pregnant or nursing. For example, tricyclic antidepressants have been linked with muscle spasms and heart, breathing and urinary problems in newborns whose mothers took the drugs immediately prior to the child’s birth. Also, the overuse of some medications while pregnant, especially opioids, may lead to dependency in newborns.

In general, women who are pregnant or breastfeeding should consult their physician before taking any over-the-counter or prescription headache medication.