This sheet is about exposure to naproxen in pregnancy and while breastfeeding. This information is based on available published literature. 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®.
The U.S. Food and Drug Administration (FDA) states people who are pregnant should not use NSAIDs after week 20 of pregnancy unless it is specifically recommended by their healthcare provider.
I take naproxen. Can it make it harder for me to get pregnant?
Some studies suggest that using naproxen and other NSAIDs might make it harder to get pregnant. This may be more likely when NSAIDs are used often or over a long period of time.
Does taking naproxen increase the chance for 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. 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?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Studies do not agree if naproxen does or does not increase birth defects.
Results from a few large studies on NSAIDs, including naproxen, did not show an increased chance of birth defects. Another study looking at 23 pregnancies exposed to naproxen did not find an increased chance of birth defects.
However, some studies have reported a small increased chance for heart defects when both naproxen and other NSAIDs are used in early pregnancy. An association with cleft lip and palate (an opening in the lip and / or the roof of the mouth) has also been reported, but has not been proven. It is not known if naproxen was the cause of the birth defects in these studies, or if they were due to other factors such as the medical conditions being treated.
Does taking naproxen in pregnancy increase the chance of other pregnancy-related problems?
Naproxen should only be used under a healthcare provider’s watch, particularly in the 2nd and 3rd trimesters. Your healthcare providers can closely monitor your pregnancy if you need to use naproxen during your pregnancy.
One study found that using naproxen during the first trimester increases the chance of the baby being smaller than expected (small for gestational age).
Using an NSAID in the 2nd half of pregnancy might lower the amount of amniotic fluid (liquid that surrounds the fetus in the uterus). If there is not enough amniotic fluid (called oligohydramnios) other problems could happen for the fetus, such as damage to the kidneys, poor lung development, joint contractures (joints become stiff or unable to move), or even death. In some cases, oligohydramnios requires an early delivery through labor induction (when the healthcare provider uses a medication to start labor early) or c-section.
Naproxen use later in pregnancy might also cause narrowing of blood vessels in the fetus.
Does taking naproxen in pregnancy affect future behavior or learning for the child?
This is not known for a number of reasons. It is difficult to connect later learning problems to one exposure during pregnancy. There is also no study that checks on later learning with naproxen use only in a pregnancy. Studies that have been done on this topic for NSAIDs in general do not agree if there is or is not a higher chance for learning or attention problems. Studies that have suggested a possible association have study design limitations that do not allow us to know if this finding was linked to the medication or other factors, such as the reason the parent took an NSAID.
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. Naproxen stays in breast milk longer than other NSAIDs. NSAIDs that leave the body quicker may be preferred for breastfeeding. Be sure talk to your healthcare provider about all your breastfeeding questions.
If a male takes naproxen, could it affect fertility or increase the chance of birth defects?
It is not known if naproxen could affect male fertility (ability to get partner pregnant) or increase the chance of birth defects above the background risk. In general, exposures that fathers or sperm donors 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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OTIS/MotherToBaby encourages inclusive and person-centered language. While our name still contains a reference to mothers, we are updating our resources with more inclusive terms. Use of the term mother or maternal refers to a person who is pregnant. Use of the term father or paternal refers to a person who contributes sperm.
