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 fentanyl might increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your healthcare provider.

What is fentanyl?

Fentanyl belongs to a class of medications known as opioids. An opioid is sometimes called a narcotic. Fentanyl is often given during surgery. It is used to treat pain. Fentanyl can be given in different ways, such as IV, injection, epidural (space around the spinal cord), transdermal (patch applied to skin), nasal spray, or buccal (pill in mouth next to cheek).

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

People break down medications at different rates. The time it takes to clear from your body also depends on how the fentanyl is being given. IV fentanyl only stays in your body for a few hours, while the patch version can last 3 or 4 days, even once the patch is removed. Be sure to talk with your healthcare providers before making any changes to your medications.

Can taking fentanyl make it harder for me to get pregnant?

Studies on women have not been done specifically on fentanyl to see if it makes it harder to get pregnant. However, it is known that long term use of opioids can affect hormones important in getting pregnant.

I just found out I am pregnant. Should I stop taking fentanyl?

No. If you are pregnant and using fentanyl regularly, talk to your healthcare provider about options that will allow you to either gradually wean off or stay on a carefully controlled dose of an opioid medication during your pregnancy. If you have been taking fentanyl regularly you should not just stop suddenly (also called “cold turkey”). Stopping an opioid medication suddenly could cause you to go into withdrawal. More research is needed to know how going through withdrawal might hurt a pregnancy. Talk with your healthcare provider about the risks and benefits of continuing or stopping your medication. Any reduction in your codeine needs to be done slowly, and under the direction of your healthcare provider.

Does taking fentanyl during my pregnancy increase the chance of miscarriage?

There are no published studies looking at whether fentanyl increases the chance of miscarriage. This does not mean there is an increased chance or that there is no increased chance, it only means that this question has not been answered. Miscarriage is one of the risks of surgery during pregnancy, and it is hard to tell if miscarriage is due to the underlying condition, the procedure, or the medications being used.

I took fentanyl in the beginning of my pregnancy. Is there a greater chance for birth defects?

Some studies have suggested that opioids may be associated with birth defects, while other studies did not find an increased risk for birth defects. There are no human studies looking specifically at fentanyl and birth defects. Studies in laboratory animals did not find an increased risk for birth defects. Based on the available information, using fentanyl is not expected to increase the chance of birth defects.

Could fentanyl cause other pregnancy complications?

Possibly. Studies involving women who chronically use some opioids during their pregnancy have found an increased risk for adverse outcomes including poor growth of the baby, stillbirth, premature delivery, and c-section. This is more commonly reported in women who are taking heroin or who are using prescribed pain medications in greater amounts or for longer than recommended by their health provider. Use of an opioid close to the time of delivery can result in withdrawal symptoms in the baby (see the section on withdrawal).

Will taking fentanyl during pregnancy affect my baby’s behavior or cause learning problems?

There are not enough studies on fentanyl to know whether there is a chance for long-term problems. Brief use of fentanyl during surgery or for post-surgical pain is not likely to cause learning or behavior problems.

I need to take fentanyl throughout my entire pregnancy. Will it cause withdrawal symptoms (neonatal abstinence syndrome) in my baby after birth?

Possibly. Studies have reported a risk for neonatal abstinence syndrome (NAS) with some opioid medicines; however, not all medications have been studied. Based on what we know about the risk of NAS with other opioids, it is likely that fentanyl also has a risk for NAS. Because there are few studies, we do not know if the risk is higher or lower than with other opioids.

NAS is the term used to describe withdrawal symptoms in newborns from medicines that a mother takes during pregnancy. For any opioid, symptoms can include difficulty breathing, extreme drowsiness (sleepiness), poor feeding, irritability, sweating, tremors (shivers), vomiting and diarrhea. Symptoms of NAS may appear at birth and may last more than two weeks. If needed, babies can be treated for NAS in the hospital. If you use an opioid in your pregnancy, it is important that your baby’s doctors know and check for symptoms of NAS, so your newborn gets the best possible care.

Can I take fentanyl while I am breastfeeding?

Possibly, depending on how it is given to you. Small amounts of fentanyl get into breast milk. Newborns are not fully developed and might have problems with the amounts from breast milk. If you have had a very brief exposure (example: IV use in surgery) then the amount in your milk is likely to be very low after 12 hours. If you take an opioid, such as fentanyl, on a daily basis, there may be concerns about your baby being very sleepy and not feeding well. Other opioids have been reported to cause difficulty with breathing, and in a few cases have even resulted in death of the baby. If you are using any opioid, your baby can be watched carefully for excessive sleepiness or poor feeding. The baby’s healthcare provider should be contacted right away if your baby has any problems. Speak to your healthcare provider about your pain and medications that can be used while you are breastfeeding.

What if the father of the baby takes fentanyl?

There are no studies looking at how fentanyl use in a man might affect his ability to get his partner pregnant or how it might affect a partner’s pregnancy. 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

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