This sheet is about exposure to naproxen in pregnancy and while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare provider.
What is naproxen?
Naproxen is a medication that has been used to treat pain and fever. It belongs to the class of medication called non-steroidal anti-inflammatory drugs (NSAIDs). Some brand names for naproxen include Aflaxen®, Aleve®, Anaprox®, Flanax®, Naprelan®, Naprosyn® and Menstridol®.
Sometimes when women find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take your medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
The U.S. Food and Drug Administration (FDA) recommend not using NSAIDs after week 20 of pregnancy unless your healthcare provider specifically recommends it. If a healthcare provider decides NSAIDs are needed after week 20 of pregnancy, they should be used at the lowest dose for the shortest time.
I take naproxen. Can it make it harder for me to get pregnant?
It is not known if naproxen can make it harder to get pregnant. Some studies suggest that naproxen and other NSAIDs might interfere with ovulation, including causing unruptured follicle syndrome, where the follicle does not release the egg at the time of ovulation. This might make it harder to get pregnant. These effects may be more likely with frequent or long-term use.
Does taking naproxen increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Some studies have suggested that taking naproxen may increase the chance of miscarriage, while others have not. As there can be many causes of miscarriage, it is hard to know if a medication, the medical condition, or other factors are the cause of a miscarriage.
Does taking naproxen increase the chance of birth defects?
Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like naproxen, might increase the chance of birth defects in a pregnancy. Most studies on NSAIDs, including naproxen, have not shown an increased chance of birth defects.
Some studies have reported a small increased chance for certain birth defects, including heart defects and cleft lip and/or palate (opening in the roof of the mouth and/or the lip), when NSAIDs are used in early pregnancy. A review of NSAID use in pregnancy has also suggested a possible small increase in the chance of some birth defects, although findings have been mixed. It is not known if naproxen, the medical condition being treated, or other factors caused these findings.
Does taking naproxen in pregnancy increase the chance of other pregnancy-related problems?
Naproxen is usually not recommended after week 20 of pregnancy. Some reports suggest that using NSAIDs in the second half of pregnancy might affect the fetal kidneys and lower the amount of amniotic fluid (the fluid around the fetus in the womb). One study also suggested that NSAID use earlier in pregnancy might have similar effects. Too little amniotic fluid (called oligohydramnios) can lead to problems like poor lung development, stiff joints, or the need for early delivery by induction or C-section. In rare cases, oligohydramnios could cause fetal death before birth.
Using naproxen later in pregnancy might cause the ductus arteriosus (an opening between the two major blood vessels leading from the heart) to close early. If the ductus arteriosus closes before it should, it can cause high blood pressure in the fetal lungs (pulmonary hypertension).
One study found that NSAID use, including naproxen, during pregnancy was associated with an increased chance of having a baby that was smaller than expected for gestational age (small for gestational age). Naproxen should only be used under a healthcare provider’s supervision, particularly in the 2nd and 3rd trimesters. Your healthcare providers can closely monitor your pregnancy, if needed.
Does taking naproxen in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if naproxen could affect a child’s learning or behavior after exposure during pregnancy. Studies on NSAIDs in general have shown mixed results, and those suggesting a possible link have important limitations (the medical condition being treated, different ways of measuring outcomes, and uncertainty about the exact timing and amount of medication used). This makes it unclear whether the medication or other factors are responsible for the outcomes reported.
Breastfeeding while taking naproxen:
Naproxen passes into breast milk in small amounts. Using naproxen is not expected to be harmful to most breastfeeding babies. There is one report of blood-related health problems in an infant who was exposed to naproxen and another medication through breast milk. It is not known if the reported health problems were due to the naproxen, another medication, or other factors. If you suspect the baby has any symptoms (vomiting, diarrhea, bleeding, trouble with feeding, or trouble with weight gain) contact the child’s healthcare provider.
Because naproxen remains in breast milk longer than some other NSAIDs, shorter-acting NSAIDs may be preferred during breastfeeding. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a man takes naproxen, could it affect his fertility or increase the chance of birth defects?
It is not known if naproxen could affect male fertility (ability to make healthy sperm) or increase the chance of birth defects. In general, exposures that men have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
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