California law allows adults 21 and older to use, carry and grow cannabis, although federal law prohibits its use. As of Jan. 1, the Medicinal and Adult-Use Cannabis Regulation and Safety Act details where California residents can use cannabis, how much can be possessed per individual and the penalties for illegal use.

Because of the new law, there is ongoing debate about the effect of cannabis use for pregnant and breastfeeding women. The California Department of Public Health’s “Let’s Talk Cannabis” campaign cautions that consuming cannabis – or marijuana, pot, weed, etc – can affect the health of the baby and is not recommended for women who are pregnant or breastfeeding, or who intend to become pregnant. Cannabinoids are chemical compounds that are found in the cannabis plant that produce the various effects of marijuana. The main cannabinoids reported by breastfeeding women are Tetrahydrocannabinol (THC) and Cannabidiol (CBD).

Tetrahydrocannabinol (THC) is the primary psychoactive compound in marijuana and binds to the CB1 receptors in the brain. Short term effects include: elation, relaxation, drowsiness/sedation, memory impairment, hunger, dry mouth, red eyes, pain relief, slowed perception of time, laughter and anxiety/paranoia.

Cannabidiol (CBD) is the primary non-psychoactive compound found in marijuana and binds to the CB2 receptors in other areas of the body. Short term effects include the reduction of: Pain, nausea, vomiting, anxiety, depression, and sleepiness.

It’s also important to understand that the potency of marijuana has increased dramatically over time. Studies have shown that the THC content present in marijuana was 4 percent in 1995 and increased to 12 percent in 2014.

The California Department of Public Health warns that no matter how cannabis is used – by smoking, vaping, eating or drinking – the THC can reach a baby in three ways: through the mother’s bloodstream and into the placenta; through breast milk and through secondhand smoke that enters the baby’s lungs. Secondhand smoke from cannabis products entering the lungs of infants contains THC as well as many of the same chemicals found in tobacco smoke.

The American Academy of Pediatrics and other professional organizations recommend that women do not use cannabis while breastfeeding, as cannabis has been shown to transfer into breast milk. The concentration present in milk is dependent on the hours since last used and the number of times used per day. The half-life is about 27 hours. “Pumping and Dumping” does not work. THC is stored in the fat cells and is slowly released over several weeks, so it stays in the breast milk.

Research shows that cannabis use during breastfeeding can have a negative health impact on the developing infant. The growth and development of the baby’s brain can be harmed. Infants exposed to breast milk that contains THC may have trouble nursing because of sedation, reduced muscular tone and poor suckling ability.

The data is important to know and understand, since the California Cannabis Health Information Initiative indicates that more than 1 in 10 pregnant and non-pregnant women reported using cannabis in the past 12 months.

As acceptance of cannabis use increases, it is important to counsel pregnant and breastfeeding mothers on the potential medical consequences of use during breastfeeding.

About the Author

Author: Natalie Mendenhall , Lactation Program Coordinator

Natalie Mendenhall is a Certified Lactation Consultant and co-coordinator of the Lompoc Valley Medical Center Breastfeeding Program. An Arroyo Grande native, she received a Bachelor of Science degree in Nursing from Touro University in Nevada in 2013. She received her California RN license in 2014. Natalie graduated as a Certified Lactation Consultant from the University of California at San Diego and became an International Board Certified Lactation Consultant in 2018. She completed internships in IBCLC at Twin Cities Hospital and Women, Infants, and Children (WIC) Food and Nutrition Service in Grover Beach.

Other Articles Written by This Author