Low-dose aspirin therapy is sometimes prescribed during pregnancy to help prevent recurrent miscarriage or to treat other conditions. Generally, however, aspirin and other nonsteroidal anti-inflammatory drugs — including ibuprofen (Advil, Motrin, others) — aren't recommended as pain relievers during pregnancy.
Before birth, a baby receives oxygen through blood from the placenta. At birth, a natural drop in prostaglandin levels in some of the baby's blood vessels drives the baby's circulatory system to reroute blood flow to the lungs. Since aspirin blocks the production of prostaglandins, taking aspirin during pregnancy — especially after 32 weeks — could trigger the baby's blood flow to be rerouted in the uterus. This could cause potentially fatal problems for the baby.
If you need to take a pain reliever during pregnancy, ask your health care provider about the options. He or she may approve occasional use of acetaminophen (Tylenol, others).
