I live in Oregon where recreational and medical marijuana is legal, and from small towns to urban streets, store fronts are as common as coffee shops. As such, it is highly accessible to anyone over the age of 21, and like smoking and alcohol, there are important possible risks to pregnant women. In addition to the pregnant woman who chooses to continue behaviors that present risk to her, customers are also seeking medical advice from the person behind the counter, asking the question, can I use these products for nausea of pregnancy?
A team of investigators from the University of Colorado decided to find out what type of information was being provided by staff members of marijuana dispensaries. The investigators posed as 8 week pregnant patients and called 465 dispensaries which resulted in useful information from 400. They asked the employees if they had products that were “recommended for morning sickness”. They also asked about any known fetal or maternal risks and whether they should check with their own health care provider.
Sixty nine percent of dispensary staff members recommended marijuana products for morning sickness and 36% said it was safe to use in pregnancy. Only 32% initially recommended that the caller check with their doctors, but after prompting, 81% eventually recommended that.
Commentary: Unfortunately, the majority of pregnant women who are using marijuana recreationally are likely not asking their provider for advice on the topic of use for morning sickness. Thus, they are seeking medical advice from marijuana sales people, who have not only a conflict of interest, but also lack of medical knowledge, and according to this study, lack of a cautionary approach to the topic. Cannabis, the marijuana plant, contains up to 100 cannabinoids, with the two that we know the most about being tetrahydrocannabinol (THC) and cannabidiol (CBD). THC acts on CB1 receptors that then yield the psychotropic effects. CBD acts through its effect on serotonin and not CB1 receptors for the most part. We currently have only a small but growing amount of evidence for the medicinal properties of cannabinoids including nausea and vomiting due to chemotherapy, some pain relief effects, anti-seizure activity in select seizure disorders and anti-inflammatory properties.
Current marijuana products contain from 0.3% THC up to 15% and now even some concentrations up to more than 50% THC. There are a plethora of products with varying ratios of CBD/THC. In addition, there is a risk of marijuana dependence and addiction with currently an estimate of 2.7 million U.S. individuals and affecting about 9% of users. This is compared to 15% of the population addicted to alcohol. And then there is the risk of addiction to the newborn, let alone other potential consequences of cannabinoid exposure in utero. It will be very difficult to determine the true impact of cannabis on the fetus, as there are too often other confounding variables such as cigarette smoke, alcohol, other recreational drugs, socioeconomic influences and nutritional habits. There have been some studies that have shown that children exposed in utero to cannabis performed more poorly in visual problem solving, motor coordination and attention deficits compared to unexposed children. Other possible effects include increased risk of stillbirth, low birth weight (if mother used cannabis more than once per week), preterm birth (mostly in those who used cannabis and were cigarette smokers). To be fair, a few older studies have not shown any differences in adverse outcomes with pregnant users vs. nonusers.
One thing for sure, marijuana use of any kind has not been proven to be safe in pregnancy. And since there is even any evidence of possible harm, we should recommend to our patients that they not use cannabis products during pregnancy – whether for recreational or medical purposes. For most women with nausea/vomiting of pregnancy, there are numerous natural and pharmaceutical options, ginger being my most favorite. That said, there are those women the serious, even dangerous nausea/vomiting (hyperemesis)…..if she has tried all other options and cannabis does relieve her debilitating condition….. I will be in a quandary about how to advise her.
Reference
Dicson B, Mansfield C, Guiahi M, et al. Recommendations from cannabis dispensaries about first-trimester cannabis use. Obstet Gynecol 2018;131:1031-1038.
