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 stop or reverse the way opioids work in the body. Naloxone can be used to stop someone from dying from an opioid overdose. Brand names include Narcan® (nasal spray) and Evzio® (auto-injector).

Naloxone is added to buprenorphine ( to make a medication commonly known as 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?

You should talk with your healthcare providers before stopping this medication.

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

There are no studies on women taking naloxone that support the possibility to increase of the chance for miscarriage.

Can taking naloxone or being treated with naloxone in the first trimester 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. Results from animal studies suggest that naloxone is unlikely to increase the chance for birth defects in humans, however, more information is needed. Very little naloxone from buprenorphine/naloxone gets into the blood when it is taken by mouth. So, small amounts of naloxone are expected to reach the developing baby. 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 in the second or third trimester cause any pregnancy complications?

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

Could being treated with naloxone for an overdose in the second or third trimester cause any pregnancy complications?

No 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 abuse opioids are at greater risk of complications. During an opioid overdose the woman’s breathing slows down. When that happens 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. The effects of opioid withdrawal while pregnant are not well understood, but it is possible that it can increase the chance for preterm delivery. More research is needed to know how a pregnant woman’s withdrawal can affect the baby and pregnancy. After treatment with naloxone for an opioid overdose a woman should let her healthcare provider 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 believed that the baby will not be able to absorb it very well.

If a woman relapses or uses opioids, she should not breastfeed until the opioid drug has been eliminated from her body and she has talked with her healthcare provider. If there is an opioid in breastmilk the baby may be sleepy, may have problems with feeding, and may have problems breathing.

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 and Pregnancy

Selected References

  • Blandthorn J, et al. 2018. Managing opioid overdose in pregnancy with take-home naloxone. Aust N Z J Obstet Gyneacol 58(4):460-62.
  • Gawronski KM, et al. 2014. Neonatal outcomes following in utero exposure to buprenorphine/naloxone or methadone. 2:2050312114530282.
  • Jumah NA, et al. 2016. Observational study of the safety of buprenorphine+naloxone in pregnancy in a rural and remote population. BMJ Open 31;6(10):e011774.
  • Debelak K, et al. 2013. Buprenorphine + Naloxone in the treatment of opioid dependence during pregnancy-initial patient care and outcome data. Am J Addict 22(3):252-54.
  • Hale TW & Rowe HE. 2017. Medications & Mother’s Milk, Seventeenth Edition. Springer Publishing Co.
  • Nguyen L, et al. 2018. Treating Women with Opioid Use Disorder during Pregnancy in Appalachia: Initial Neonatal Outcomes Following Buprenorphine+Naloxone Exposure. Am J Addict 27(2):92-96.
  • Preston KL, et al. 1990. Effects of sublingually given naloxone in opioid-dependent human volunteers. Drug Alcohol Depend 25(1):27-34.
  • Wiegand SL, et al. 2016. Naloxone and Metabolites Quantification n cord Blood of Prenatally Exposed Newborns and Correlations with Maternal Concentrations. AJP 6(4)e385-90.
  • Zelner I, et al. 2015. Acute Poisoning During Pregnancy: Observations from the Toxicology Investigators Consortium. J Med Toxicol 11(3):301-08.