This sheet talks about exposure to naloxone in a pregnancy or while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.

What is naloxone?

Naloxone is a medication used to block the effects of opioids. Examples of some opioids are heroin, morphine, codeine, oxycodone, and hydrocodone. Naloxone has also been used to stop someone from dying from an opioid overdose. Brand names for naloxone are Narcan® (nasal spray) and Evzio® (auto-injector).

Naloxone combined with buprenorphine ( is a medication whose brand name is Suboxone®. This combination drug is used to treat opioid addiction.

Naloxone is added to the opioid pain medication pentazocine (Talwin NX®) to prevent pentazocine abuse.

I take naloxone or I was recently treated for an overdose with naloxone. Can it make it harder for me to become pregnant?

Studies have not been done to see if taking naloxone could make it harder for a woman to get pregnant.

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

Do not stop taking naloxone without talking to your healthcare provider, who will also discuss the risks of not taking the medication.

Can taking naloxone or being treated with naloxone for an overdose increase the chance for a miscarriage?

Miscarriage can occur in any pregnancy. Studies have not been done to see if naloxone increases the chance for miscarriage.

Does taking naloxone increase the chance for birth defects?

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. Very little naloxone from buprenorphine/naloxone gets into the blood when it is taken by mouth. So, very small amounts of naloxone are expected to reach the developing baby. There is a limited number of studies on naloxone use during pregnancy. Studies in women who were taking naloxone during the first trimester did not find an increased chance of birth defects above the background risk in their babies. No studies have been done to see if treatment with naloxone for an overdose in the first trimester can increase the chance for birth defects.

Could taking naloxone daily as part of buprenorphine/naloxone cause other pregnancy complications?

Studies on the combination buprenorphine/naloxone do not suggest an increased chance for complications including low birth weight, prematurity or stillbirth when it is taken in the second or third trimester.

Could being treated with naloxone for an overdose cause other pregnancy complications?

Studies have been done to see if naloxone causes pregnancy complications when it is used to treat an overdose in the second or third trimester. Pregnant women who misuse opioids can have a greater chance for pregnancy complications. During an opioid overdose the woman’s breathing slows down. If a mother is not breathing well, the baby may not get enough oxygen for a period of time. That can have a harmful effect on the baby’s development. Naloxone helps return breathing to normal. It can also put the mother into withdrawal from the opioid that she was using. The effects of opioid withdrawal while pregnant are not well understood. After treatment with naloxone for an opioid overdose a woman should let her healthcare providers know about it as soon as possible.

Could taking naloxone in pregnancy cause long-term problems in behavior or learning for the baby?

No studies have been done to see if being exposed to naloxone in pregnancy can affect the child’s long-term development.

Can I breastfeed while taking naloxone or after being treated with naloxone?

It is not known if naloxone gets into breastmilk. But if naloxone does get into breastmilk, it is thought that a nursing baby would not be able to absorb it very well.

If a woman needs naloxone for an opioid overdose, she should not breastfeed until the opioid drug is gone from her body. If there is an opioid in breastmilk the baby may be sleepy, may have problems with feeding, and may have problems breathing. Talk to your healthcare providers about all of your breastfeeding questions and concerns.

What if the baby’s father takes naloxone or was treated with naloxone for an overdose?

There are no studies looking at the effects on a pregnancy if a father takes naloxone. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. To learn more, please see the MotherToBaby fact sheet on Paternal Exposures

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