In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to naproxen may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What is naproxen?

Naproxen is a medicine that is commonly used to treat minor pains associated with arthritis, headache, muscle aches, toothache, backache, common cold, menstrual cramps and for the temporary reduction of fever. Other names for naproxen include Aleve® (available over the counter), Anaprox®, Napralen®, and Naprosyn®.

Naproxen is in a class of medicines called non-steroidal anti-inflammatory drugs (NSAIDs). Other medicines in this class include aspirin and ibuprofen (see MotherToBaby fact sheet on Ibuprofen and Pregnancy at http://mothertobaby.org/fact-sheets/ibuprofen-pregnancy/pdf/).

I take naproxen regularly at high doses for my medical condition. Can this make it more difficult for me to become pregnant?

It is unclear how naproxen use may affect a woman’s ability to become pregnant, i.e. fertility. Some studies suggest that NSAIDs in general, not just naproxen, may make it more difficult to become pregnant. However, this seems more likely when someone is using NSAIDs often or over a long period of time.

Until more information is known, it is recommended that women who are trying to become pregnant avoid the use of NSAIDs, unless the NSAIDs are for the treatment of a serious, ongoing condition. In such cases, it will be important to talk with your health care provider before making any changes regarding your treatment.

I am taking naproxen, but I would like to stop taking it before becoming pregnant. How long does the drug stay in my body?

The amount of time it takes for a medication to be cleared from the body will be different from person to person. However, it generally takes about 2-3 days for nearly all (about 97%) of naproxen to be cleared from the body.

Can taking naproxen early in pregnancy increase my chance for miscarriage?

It is not clear if the use of naproxen increases the chance for miscarriage. Some reports suggest an increased chance of miscarriage with the use of any NSAIDs in early pregnancy, but other studies have not. However, you should not be overly concerned if you had some naproxen before you realized you were pregnant.

Does naproxen cause birth defects when taken in the first trimester?

Not likely. The results from a few large studies on NSAIDs, including naproxen, did not show an increased chance for birth defects.

A small increased chance for heart defects has been reported in some studies looking at naproxen and other NSAIDS in early pregnancy. Other factors, such as the health condition for which naproxen was taken, could also be the cause. A small association with cleft lip and palate (i.e. opening in the lip or roof of the mouth) and naproxen use has also been reported but cannot be proven. In another study where 23 pregnant women took naproxen every day to help treat lupus and arthritis, there were no birth defects seen in their children.

Can I take naproxen in my third trimester?

Naproxen is not recommended in the third trimester. This is due to concerns, especially after the 30th week of pregnancy, that naproxen use in the third trimester is associated with a chance of premature closure of the ductus arteriosus (i.e. a vessel near the fetal heart that stays open during pregnancy and closes soon after birth). Closure of this vessel too early can lead to high blood pressure in the baby’s lungs (i.e. pulmonary hypertension). Also, the use of NSAIDs in the third trimester may slow down labor or cause low levels of amniotic fluid (i.e. oligohydramnios).

The use of naproxen during the third trimester should only be done under the direction of your health care provider. If treatment is required, your health care provider may want extra ultrasounds to better follow your baby’s heart and amniotic fluid amount. It is recommended to use the lowest dose that effectively treats your condition in order to limit exposure to the baby.

Can I take naproxen while I breastfeed?

Naproxen has been found to enter breast milk in small amounts and stays in breast milk longer than other NSAIDs. Based on available information, it is unlikely that naproxen use would be harmful for a breastfeeding baby. However, there is one report of blood-related health problems in a breastfed infant whose mother took naproxen along with another medicine. It is not known if naproxen or the other medicine caused this infant’s problems. Due to this concern and the long time naproxen stays in breast milk, it may be best to take a different NSAID, especially if breastfeeding a newborn (i.e. less than a month old) or premature baby (i.e. born before 37 weeks). Talk to your health care provider about all your breastfeeding questions.

What if the father of the baby takes naproxen?

There are no studies looking at possible risks to a pregnancy when the father takes naproxen. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures and Pregnancy at http://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/.

References Available by Request.