Cannabis contains hundreds of chemicals, many of which belong to the cannabinoid group. Cannabidiol (CBD) is just one of these natural compounds. Unlike the more well-known cannabinoid, tetrahydrocannabinol (THC), CBD does not produce a “high” and is considered to have minimal side effects. Researchers are studying CBD and its potential for treating a number of medical conditions, and it has already shown promise for children with epilepsy.
CBD can be produced and used in many forms, including oils that are smoked or ingested, tinctures, sprays, edibles and salves applied directly to the skin. Although not currently available in Canada, a preparation of CBD called Epidiolex is now being studied in clinical trials.
Some cannabis products available to Canadians under the Access to Cannabis for Medical Purposes Regulations (ACMPR) contain a much higher dose of CBD than THC, though they are not CBD-exclusive.
Mothers want more information
CBD has shown potential as a treatment for a number of medical issues that may also present themselves during pregnancy or postpartum. Unfortunately, none of these studies have included pregnant or nursing mothers and it would be difficult to assess whether the benefits may carry over to different populations. One narrative review found a benefit of CBD treatment for anxiety, while other studies have looked at combination THC/CBD for chemotherapy-induced nausea and vomiting and neuropathic pain.
During pregnancy, many women suffer from nausea and vomiting, migraines and chronic pain along with mental health issues such as anxiety or depression. After a baby is born, postpartum depression is common—not to mention physical pain after giving birth—and new mothers seek treatments that will not have adverse side effects for their nursing babies.
Motherisk, an organization based out of the Hospital for Sick Children, receives on average three calls per week from nursing mothers inquiring about marijuana use. They conclude that “cannabinoid exposure through milk has not been shown to increase neonatal risk, but there are no appropriate studies of this.” There is some limited research that shows that THC compounds will concentrate in breast milk in moderate amounts.
Health professionals don’t have answers for their patients, either. “We can’t even tell women to make an informed decision, because there’s just not enough information out there to be informed,” says Edith Kernerman, a lactation consultant with Breastfeeding Inc.
What we do know
The limited research surrounding cannabinoids and pregnant or lactating mothers focuses almost entirely on THC. For example, one study strongly suggests exposure to cannabis in utero has adverse effects on birth weight and increases the risk a baby will be admitted to the Neonatal Intensive Care Unit (NICU). Studies of long-term side effects of marijuana use show problems with cognitive development and academic achievement. Behaviour can also be affected, including increased hyperactivity, attention deficits and substance abuse or delinquency among adolescents.
Despite these results, marijuana continues to be the most common illicit drug used during pregnancy. Approximately 11 per cent of women of childbearing age reported past-year use of cannabis, and anywhere from 2 to 5 per cent of women report using marijuana in pregnancy.
The few studies that exist for strictly CBD are either in vitro (meaning studies of cells), or animal studies. One in vitro study concluded that CBD use during pregnancy may change the physiological characteristics of the placenta. However, this study was looking at chronic exposure over 24 to 72 hours. Patients using CBD would be doing so at a smaller dosage over a greater period of time.
Waiting for science to catch up
At this point, much more research is needed to study the maternal risks associated with medical use of CBD. Although there are promising results emerging for the treatment of many conditions—including nausea and vomiting— research of CBD is still in its infancy.
Kernerman’s hope is that more research comes out in the future, so that healthcare providers can provide clear answers for their patients. In the meantime, women are advised to seek treatments with conclusive evidence as to the benefits and risks for babies.