Study supports need for cannabis use screening during pregnancy in legalized states

In U.S. states where cannabis is legal for medical and recreational purposes, pregnant women were more likely to report using it compared with their counterparts in states where only cannabidiol is legal, a recent study found.

“Despite evidence suggesting that cannabis use during pregnancy is associated with adverse neonatal outcomes, its use among pregnant women in the United States has increased significantly,” Kathak Vachhani, a medical student at the University of Toronto, and colleagues wrote.

A 2019 JAMA Network study previously found that the rate of medical and non-medical cannabis use among pregnant women rose from 3.4% in 2002 to 7% in 2017.

Despite that increase, Vachhani and colleagues noted that the extent of how legalization is affecting cannabis use trends in pregnancy is still unknown.

“Insufficient screening for use, inadequate prenatal counseling about cannabis, and widespread legalization have resulted in the misperception among many pregnant users that cannabis is a safe substance,” they wrote. “Understanding usage in legal versus illegal states serves as the first step towards developing cannabis-related public health policies focused on safeguarding pregnant women and newborns in states where cannabis is legalized.”

Using data from the Behavioral Risk Factor Surveillance System survey from 2017 to 2020, Vachhani and colleagues assessed responses on cannabis use among 1,992 pregnant women aged 18 to 54 years.

Respondents were then categorized into three subgroups based on their state’s cannabis legalization policy:

• CBD-only use (n = 426);
• medical use (n = 1,114); and
• adult use (n = 394).

The researchers found that cannabis use over the last 30 days was reported by:

• 2.4% (95% CI, 0-4.4) of respondents from the CBD-only use group;
• 7.1% (95% CI, 4-10.1) of respondents in the medical use group; and
• 6.9% (95% CI, 3-10.9) of respondents in the adult use group.

Compared with the CBD-only group, the unadjusted odds of cannabis use by the medical use group was 3 (95% CI, 1.2-7.8), which Vachhani and colleagues pointed out rose to 4.5 (95% CI, 1.4-14.7) following adjustment.

Meanwhile, when also compared with the CBD-only group, the adult use group had the same unadjusted odds of cannabis use of 3 (95% CI, 1.1-8.3), which increased to 4.7 after adjustment (95% CI, 1.3-16.2).

Across all groups, smoking was the most common form of intake, while 49% of respondents reported the usage being partially or entirely for recreational purposes.

Although most of the respondents were categorized in the medical-use group, “only a small proportion of users reported using for strictly medical reasons,” the researchers wrote.

The study was limited by the small sample size, a lack of information regarding the timing of pregnancy and a lack of information regarding the chemical composition of cannabis consumed, according to the researchers.

Vachhani and colleagues said their findings highlight a need for prenatal and primary care providers to screen and consult patients regarding cannabis use during pregnancy, “particularly in states where it is legal.”

The researchers acknowledged that while cannabis has been associated as an effective treatment for nausea and vomiting — making it potentially more suitable to pregnancy-related conditions that could be more harmful to the fetus than cannabis if untreated — there is “an urgent need for a risk-benefit analysis of cannabis versus no treatment or current treatment options for pregnancy-related conditions.”

“Ultimately, it is such granular information that will help identify opportunities for interventions to ensure safer use, if possible, during pregnancy,” they wrote.

References:

• Pregnant women’s cannabis usage in legalized US states raises calls for screening. https://www.eurekalert.org/news-releases/972101. Published Nov. 29, 2022. Accessed Nov. 30, 2022.
• Vachhani K, et al. Am J Drug Alcohol Abuse. 2022;doi:10.1080/00952990.2022.2136035.
• Volkow N, et al. JAMA. 2019;doi:10.1001/jama.2019.7982.