Our study provides the first estimates of characteristics associated with different modes of preconception cannabis administration. Results suggest that mode of administration may be a proxy for socioeconomic status, with smoking and blunt use being more common among populations who face more structural disadvantages  and use of edibles and vaping being more common among those who face fewer structural disadvantages . Future qualitative studies are needed to investigate how price, social, cultural and demographic factors influence individuals’ choices about how to administer cannabis, reasons for use, and understanding of health risks. Individuals tend to develop their substance use patterns prior to pregnancy, and preconception use of cannabis is among the strongest predictors of prenatal cannabis use . Although the psychoactive effects, health risks, and timing and duration of peak effects vary with mode of cannabis administration , it is unknown whether the likelihood of quitting cannabis use prior to pregnancy,mobile grow system or the potential adverse health effects to infants exposed to cannabis in utero vary depending on maternal mode or combinations of modes of cannabis administration.

These questions warrant further investigation. As the diversity of products on the market continues to increase, surveillance of how individuals administer cannabis before and during pregnancy will be critical to inform clinical guidance, public policy and prevention and intervention strategies across diverse populations for reducing harms associated with cannabis use.  On October 17, 2018, Canada became the second country in the world to legalize non-medical cannabis . Briefly, the Cannabis Act permits adults aged 18 and over to purchase cannabis, cultivate up to four plants, and possess up to 30 g of dried flower  in public . Canadians can access legal non-medical cannabis through physical and online retail stores, sharing small amounts among friends and family, or growing personal cannabis plants . Prior to the legalization of non-medical cannabis in 2018, home cultivation was permitted for consumers with medical authorization under certain conditions . Those with medical authorization were permitted to grow their own cannabis; or designate someone to grow cannabis on their behalf . In October 2018; immediately prior to legalization of non-medical cannabis, less than 1% of Canadians were registered with Health Canada for medical cannabis and 7.5% of Canadians with medical authorization had an active registration to grow or designate someone to grow on their behalf .

In October 2020; approximately two years after non-medical legalization, this percentage had risen to 11.3% . Under the Cannabis Act, unchanged from the preceding “Access to Cannabis for Medical Purposes” regulations, the number of plants grown for medical consumption is determined by the daily quantity of cannabis outlined in the patient’s medical authorization . In general, for every gram of dried flower authorized, five plants are permitted indoors or two outdoors . For instance, if the patient is authorized two grams of dried flower per day, ten plants would be permitted indoors. Therefore, Canadians growing for medical purposes may have higher limits of the number of plants grown than Canadians growing for non-medical purposes. Moreover, provinces and territories have jurisdiction on retail sales and distribution, including prohibiting home cultivation, and so regulations vary across the country . For example, Manitoba and Quebec prohibit home cultivation of non-medical cannabis grow supplies, whereas all other provinces allow up to four plants . In a legal market, allowing residents to grow their own cannabis at home provides a relatively low-cost source of cannabis for those who prefer not to purchase from retail stores or pay taxes, to have more control over cannabis strains, or for those growing for enjoyment . Indeed, home cultivation could support the objectives of the Cannabis Act, if those growing a personal supply are doing so instead of sourcing illegally .

Conversely, home cultivation has the potential to undermine objectives of the Cannabis Act, which include reducing the illegal market and prevent underage consumption . Home cultivation could provide easier access to children in the home, allow opportunity for illegal resale, and avoid the strict regulations that were created to protect public health . Further research is needed on home cultivation in Canada since legalization, including who grows their own cannabis plants. When compared to other supply sources such as friends and family or retail stores, home cultivation rates have been found to be comparably modest, both before and after legalization . In the National Cannabis Survey; 8.0% of past three-month cannabis consumers reported getting their cannabis by growing their own or someone growing it for them before legalization in the first quarter of 2018 .