Marijuana, Pregnancy and Breastfeeding

Christine Sweeney, LICSW Program Manager, Parent Connection, BIDMC

SEPTEMBER 03, 2018


In 2012 Massachusetts legalized the use of medical marijuana and in 2016 legalized its recreational use. While marijuana is known to successfully treat symptoms for a range of medical issues, what exactly are the implications for pregnancy and for breastfeeding?

There is a rising concern of an increase use of marijuana by pregnant women to treat symptoms of nausea and vomiting. This despite the fact that there is no evidence citing marijuana as an effective treatment for these symptoms and clear evidence that marijuana use may pose significant risk to the developing fetus.

Jan Gutweiler, RN, BSN, IBCLC, ANCL, Former Lactation Program Coordinator, Beth Israel Deaconess Medical Center, Boston, MA shares the following information in regards to marijuana and breastfeeding:

Some quick facts:

  • Marijuana is the cannabis plant which contains a large number of biologically cannabinoids (> 200 have been identified)
  • The active molecules regulate functions such as the brain and nervous system and certain immune cells
  • Marijuana has a chemical in it called delta-9-tetrahydrocannabinol
  • (also called THC). This chemical can affect how your brain works
  • What has been definitely proven is that marijuana taken by the breastfeeding mother, in any form (smoke, brownies, tea), will make it into the baby’s body

While few clinical studies have looked specifically at the risks of smoking marijuana while breast-feeding, and many of the studies that have examined this question were conducted several decades ago, there are clear indications that using marijuana and breastfeeding are not a healthy mix.

You may pass THC and other chemicals from marijuana to your baby through breast milk. If you breastfeed your baby and smoke marijuana, your baby may be at increased risk for problems with brain development. Marijuana also may affect the amount and quality of breast milk you make. The American Academy of Pediatrics recommends that breastfeeding moms stay away from marijuana to help keep breast milk safe and healthy.

Marijuana is on the American Academy of Pediatrics Committee on Drugs (2001) list of drugs of abuse for which adverse effects on the infant during breastfeeding have been reported.

There are insufficient data to evaluate the effects of marijuana use on infants during lactation and breastfeeding, and in the absence of such data, marijuana use is discouraged.

THC decreases the amount of milk produced by suppressing the production of prolactin and, possibly, by a direct action on the mammary glands.

Marijuana can cause sleepiness in the baby, which can lead to slow weight gain and possibly slow overall development in the baby long term. In addition, babies whose mothers smoke marijuana regularly have a higher risk of SIDS.

In summary, there is increasing concern about the use of marijuana or other similar products in pregnancy and in breastfeeding mothers. Data continues to suggest that cannabis may produce long-term sequelae, such as reduced cognition and changes in mood and reward.

Both human cohort studies and studies in animals clearly suggest that early exposure to cannabis is not benign and that cannabis exposure in the perinatal period may produce long-term changes in behavior and mental health.

While the effect of cannabis on infants from breastfeeding mothers is limited, cannabis use in breastfeeding mothers should be strongly discouraged. Thus, in pregnant and breastfeeding mothers, this drug should no longer be viewed as safe.

If you have additional questions, please speak to your obstetrician or your pediatrician you can also access on line:

The American College of Obstetricians and Gynecologists’ Breastfeeding page, available at

Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
View All Articles