Marijuana and Breastfeeding Guide for MMJ Patients

The possible health implications of combining marijuana and breastfeeding will be of crucial importance to pregnant women hoping to breastfeed or MMJ patients who are currently nursing. This is because the wish to provide the physical and social benefits of breastfeeding may come into conflict with treating an existing condition with medical marijuana.

Currently, there's insufficient evidence to confirm whether or not cannabis consumption while breastfeeding is safe. Breastfeeding women need to be aware of the possible consequences of MMJ use during pregnancy and breastfeeding and ask their doctor for advice.

Does THC Pass to Breast Milk?

Yes, THC passes to breast milk. However, the degree to which it's passed on through breast milk is difficult to calculate accurately. Due to ethical considerations, there are no randomized controlled trials that have studied the effect of marijuana use by pregnant and breastfeeding women. However, various studies have attempted to offer conclusions about if or how much THC is passed through to the breast milk of THC-positive mothers.

For example, one study reported that infants could ingest 0.8% of the weight-adjusted maternal intake of one joint [1]. With chronic maternal marijuana use, THC can accumulate in human milk in higher concentrations. Logically, a higher dose or more frequent use may be linked to a higher risk of infant exposure to THC.

How Long Does THC Persist in Breast Milk After Consumption?

How long THC persists in human breast milk appears to depend on factors including the frequency of use. The limited pool of research means that it’s difficult to find a categorical answer to this question. However, the duration of detection of THC in milk has been found to range from 6 days to greater than 6 weeks in different studies.

The cannabinoid THC—the psychoactive element found in cannabis—is extremely fat-soluble and persists in consumers' body fat. For this reason, THC is slowly released over days or even weeks; how long this continues can depend on the extent of use.

Risks of Cannabis Exposure for Nursing Infants

At the time of writing, 38 states including Arizona plus the District of Columbia have legalized the use of medical marijuana. The growing normalization of cannabis use in many parts of society may lead to misconceptions about the safety of its use in circumstances such as breastfeeding.

Breastfeeding mothers need to understand the potential risks of cannabis use, even when it's used to treat a qualifying condition with a new or renewed medical marijuana card. This is because there is evidence to suggest that infants exposed to THC in the mother's milk can experience a variety of health issues. 

For example:

• Seabrook et al. (2017) noted that marijuana use could have a detrimental effect on infant development and decreased motor development in children at one year old.

• THC could also theoretically alter brain cell metabolism [1] because the most important phase of brain growth happens during the baby's first months of life. Animal studies give some weight to this theory, but no conclusive evidence exists in humans.

• Be aware that smoking marijuana can also expose your infant to the harmful chemicals contained in cigarette or marijuana smoke.

Effect of Marijuana Use on Lactation

Apart from the risk of passing THC on to infants via breast milk, animal studies indicate that cannabis might inhibit the production of prolactin, causing a reduced rate of milk production. Human studies would be required to show whether this also occurs in humans.

Effect of Marijuana Use During Pregnancy

Consuming marijuana during pregnancy has been linked with certain risks such as low birth weight and an increased risk of stillbirth.

When considering the risks of breastfeeding as an MMJ patient who is currently pregnant, your doctor may also advise you on the pros and cons of getting a medical card while pregnant.

Avoiding Infant Exposure Can Be Difficult

Some breastfeeding mothers try to avoid exposing their infants to substances like alcohol by timing consumption carefully. However, THC can be detected in breast milk as quickly as one hour after consumption and be present for up to six days after. This makes it difficult to avoid infant exposure when consuming marijuana.

Official Recommendations

Getting clear advice on how to proceed as an MMJ patient can be confusing, especially for breastfeeding mothers who receive conflicting advice. A survey of lactation experts revealed that 41% recommended continued breastfeeding despite marijuana use, claiming that the benefits outweigh the potential risks. Only 15% of the surveyed experts recommended that women should stop breastfeeding if they can't stop consuming marijuana.

This survey suggests that women may be receiving differing advice. Official guidelines, though, advise women not to mix breastfeeding and marijuana, as data are insufficient (due to cannabis being federally illegal) to recommend one way or another:

• The Centers for Disease Control and Prevention website recommends not using marijuana or any products that contain CBD in any form while breastfeeding, as “data are insufficient to say yes or no” as to whether this is safe.

• In its policy statement on Breastfeeding and the Use of Human Milk, The American Academy of Pediatrics states that the use of cannabis while breastfeeding is contraindicated due to concerns about the potential effects on the child’s neurobehavioral development. However, the AAP clarifies in its clinical report entitled Marijuana Use During Pregnancy and Breastfeeding that mothers who habitually consume certain substances are encouraged to continue breastfeeding, and at the same time, are strongly encouraged to abstain completely from marijuana, alcohol, tobacco, and other drugs.

Getting expert advice during pregnancy and breastfeeding is essential both for your own and your child’s health. Speak frankly with your doctor who will advise you on how to proceed with your medical marijuana treatment schedule while breastfeeding.

Inform Yourself and Seek Professional Advice

Medical marijuana patients must weigh up the health benefits and potential risks of marijuana use while breastfeeding. Speak to your medical provider about alternative treatment options if you would prefer not to consume cannabis while nursing your child.

Because there is currently insufficient data to prove categorically whether or not postnatal exposure to marijuana is safe, abstaining from cannabis and cannabis-based products is often advised. Be sure you're aware of all the possible consequences sustained marijuana use during breastfeeding could have and consult an experienced MMJ doctor for more personalized advice.