Marijuana and Breastfeeding

By Krista Gray, IBCLC. Last updated October 17, 2013.

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The use of marijuana (cannabis) is on the rise in the United States.  Two states – Colorado and Washington – legalized cannabis by state referenda in the 2012 elections and nearly half of the remaining 50 states have laws legalizing its use in various ways.  Whether as an illegal drug of abuse or for medical purposes, more and more people are using marijuana to varying degrees.

The National Institute on Drug Abuse has published research based on national surveys showing that 19% of 18-25 year olds have used marijuana in the past month and 4.8% of those ages 26 or older have done so in the past thirty days.1 This, coupled with the fact that up to half of all pregnancies in North America are unplanned, has lead many pregnant and lactating women to want accurate information about whether or not marijuana has negative effects on a fetus or nursing baby.2

Is marijuana safe to use while breastfeeding?

The American Academy of Pediatrics states that since marijuana can be found in breast milk and there is concern about a baby’s neurobehavioral development over the long-term, marijuana should not be used during pregnancy or breastfeeding.3 THC, the active component in marijuana, is highly lipid soluble, which means it readily passes into breast milk.  The body also stores THC for weeks to months, so babies will continue to show trace amounts of the drug in their bodies for several weeks after a breastfeeding mother no longer uses it.

While cannabis readily passes from breast milk to a baby’s system, the amounts found in breast milk are still considered insignificant to producing psychoactive affects in a baby even with mothers who are chronic users.4 The effects of THC in breastfed babies have not been well studied, though the potential for high concentrations of accumulation are possible with chronic use.5

How does marijuana impact a breastfeeding mother?

A mother’s breast milk supply may be negatively impacted by marijuana use.  Prolactin, a hormone that is responsible for both initiating and maintaining lactation, is reduced with marijuana use.6 Since prolactin is essential for milk production, a low milk supply could be yet another negative side effect.  And, while using marijuana, a mother may experience hallucinogens, euphoria, and then deep sleep – all of which could prevent her from taking care of her baby’s needs.

How does marijuana use impact a baby?

Though the impact of maternal marijuana use is greater while a baby is in utero than during breastfeeding, a newborn baby’s brain is rapidly growing and developing and there is a significant chance that marijuana can negatively impact this growth.  Not only can the THC in breast milk have a negative effect on a baby, but the environmental exposure will also impact an infant.  However, in this case, breast milk will have a more ameliorating affect with its living antibodies than manufactured formula.

Regardless, a mother who is breastfeeding and using marijuana should speak with her health care provider and seek appropriate counseling and help so she can continue to breastfeed her baby.  Breastfeeding promotes bonding and security and its unique makeup of vitamins, minerals, and immunological properties can help a baby achieve optimum growth and development – something especially important if they have been exposed to marijuana in utero.

While individual mothers may need to discuss the risks and benefits of marijuana use during pregnancy or lactation with their health care provider, the overall message to women is that marijuana use during pregnancy and lactation should be avoided.  Any woman of childbearing age should consider the potential impact of marijuana usage and either take precautions against pregnancy or discontinue its use during this time in her life.

Show 6 footnotes

  1. National Institute on Drug Abuse, 2011 National Survey of Drug Use and Health for ages 12 and older on Marijuana/Hashish.
  2. Walker, A. et al. (1999) Neurodevelopment and neurobehavioral sequelae of selected substances of abuse and psychiatric medications in utero. Child & Adolescent Psychiatric Clinics in North America, 8, 845-867.
  3. Breastfeeding and the Use of Human Milk. February 27, 2012. Pediatrics.
  4. Hale, T. (2012) Effects of Marijuana on the Fetus and Breastfeeding Infants. Texas Tech University Health Services Center.
  5. Djulus, J., et al. (2005) Motherisk Update Marijuana use and breastfeeding. Canadian Family Physician, volume 51.
  6. Hale, Thomas. (2012) Medications and Mother’s Milk 15th ed. Amarillo, TX: Hale Publishing.