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Nahed O. ElHassan, M.D., Ph.D., MPH; Bradley C. Martin, Pharm.D., Ph.D.
UAMS Researchers Shed Light on Medical Cannabis Use During Pregnancy in Arkansas
| LITTLE ROCK — When it comes to medical cannabis use by pregnant Arkansans, healthcare providers often face a difficult reality: There is still much they do not know.
A team of University of Arkansas for Medical Sciences (UAMS) researchers is now working to fill that knowledge gap by providing the first population-level look at how pregnant women in Arkansas purchase medical cannabis and how those purchasing patterns change throughout pregnancy.
The study, “From Card to Cradle: Examining Medical Cannabis Purchasing Among Pregnant Women in Arkansas,” was recently published in the American Journal of Obstetrics & Gynecology MFM and represents a key step toward understanding the potential effects of cannabis exposure on mothers and babies.
Researchers examined 72,992 pregnancies in Arkansas from May 2019 to August 2022 using state- and nationwide records to create a dataset that allowed them to study cannabis purchasing before and during pregnancy. (In Arkansas, medical cannabis was legalized in 2016, and the first dispensary opened on May 11, 2019.)
The study shows that 1.62% or 1,185 of Arkansas pregnancies during that time involved medical cannabis purchases.
“Among women who used medical cannabis, about two-thirds continued purchasing both before and during pregnancy, while about one-third started purchasing during pregnancy,” said Nahed O. ElHassan, M.D., Ph.D., MPH, the study’s first author and a professor of pediatrics in the Division of Neonatology at UAMS who treats patients in the Neonatal Intensive Care Unit at Arkansas Children’s Hospital.
“A smaller group of women who had purchased cannabis before pregnancy stopped once pregnancy began. We also found that cannabis purchasing occurred during all trimesters of pregnancy,” she added.
The findings are important because both the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics recommend discontinuing cannabis during pregnancy, given limited safety data and the absence of any FDA-approved indications for cannabis use in pregnancy.
“In clinical practice, we do see pregnant women using cannabis, but there is still limited and sometimes unclear evidence about how it may affect mothers and babies,” said ElHassan, who recently completed a Ph.D. in Pharmaceutical Evaluation and Policy in the UAMS Graduate School. “This lack of clear information makes it difficult for healthcare providers to properly counsel patients and shows that more research is needed.”
The most common medical reason women reported for receiving medical cannabis was post-traumatic stress disorder (PTSD), and the most commonly purchased product was plant-based cannabis. The amount of tetrahydrocannabinol, or THC, the primary psychoactive component in cannabis, purchased during pregnancy was substantial across the cohort, including both women who initiated cannabis purchasing during pregnancy and those who continued use from before pregnancy.
The study also identified several patterns of medical cannabis use among pregnant women. Women who purchased medical cannabis during pregnancy were more likely to be older than 30 years, white, insured through Medicaid, and tobacco users.
The analysis showed that higher THC purchasing was more common among women who continued cannabis use throughout pregnancy, while lower THC purchasing was seen among younger women, women with private insurance, women who received prenatal care, and women living in smaller towns or rural areas compared with large metropolitan areas.
Building on previous work and next steps
The findings follow earlier work on medical cannabis usage in Arkansas from a research team that included Bradley C. Martin, Pharm.D., Ph.D., a professor in the UAMS College of Pharmacy Division of Pharmaceutical Evaluation and Policy, and the study’s senior author.
“Cannabis is an interesting drug from a pharmacologic and policy perspective,” he said. “From a regulatory framework, it is the only product that I know that is classified by the DEA as a Schedule I drug, where it is legally available as a medical therapeutic in states like Arkansas, while in other states it is legal recreationally.”
Martin was the first author of a 2024 paper examining medical cannabis purchases in Arkansas between May 2019 and August 2022. That research showed that the average THC purchased per person per day exceeded the typically recommended daily doses for therapeutic uses and said further research was warranted to assess the safety and benefits of medical cannabis.
The American Journal of Obstetrics & Gynecology MFM study also showed high daily usages of THC at approximately 137 mg per day during pregnancy, three or four times higher than the typical maximum daily THC amount recommended for non-pregnant adults by expert consensus.
Martin, who has spent much of his career studying mental health and substance use disorders, said the high daily THC doses suggest there might be a significant amount of medical cannabis being diverted to nonauthorized medical uses or recreational uses since Arkansas does not provide a legal pathway for recreational use.
“The high daily THC rates we are seeing also suggest that a portion of users, pregnant and non-pregnant alike, are chronically using cannabis at high doses,” he said. “High daily use is associated with higher rates of mental health disorders such as schizophrenia and mood disorders, potential cognitive decline, potential cardiovascular and pulmonary risks, and, of course, increased risk of cannabis use disorder. In the maternal context, we do not fully know the risks to the offspring when mothers use cannabis at high levels when they are pregnant.”
ElHassan’s and Martin’s current research was supported by a 2024 Translational Research Institute Clinical and Translational Science Pilot Program (CTSP2) award, which allowed the researchers to access and connect multiple statewide databases and begin studying medical cannabis purchasing patterns among pregnant women. The Arkansas Center for Health Improvement (ACHI), an independent health policy and research organization served as the project’s honest broker and securely linked these statewide data sources.
“The pilot award helped us generate early findings that showed how cannabis was being purchased and used during pregnancy at the population level,” ElHassan said. “These results also helped us identify important unanswered questions, especially regarding how much cannabis pregnant women may be exposed to and how those exposure patterns vary over time.”
ElHassan, Martin, and team are now examining whether prenatal medical cannabis exposure is associated with outcomes such as preterm birth, low birth weight, and the need for neonatal intensive care. They are also evaluating maternal outcomes, including gestational hypertension, preeclampsia, and gestational diabetes.
Future studies will investigate whether prenatal cannabis exposure may be associated with longer-term childhood outcomes, including behavioral, developmental, and educational measures.
Research reported in this release was directly supported by the National Center for Advancing Translational Sciences of the National Institutes of Health under award number UM1 TR004909. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
UAMS is the state’s only health sciences university, with colleges of Medicine, Nursing, Pharmacy, Health Professions and Public Health; a graduate school; a hospital; a main campus in Little Rock; a Northwest Arkansas regional campus in Fayetteville; a statewide network of regional campuses; and eight institutes: the Winthrop P. Rockefeller Cancer Institute, Jackson T. Stephens Spine & Neurosciences Institute, Harvey & Bernice Jones Eye Institute, Psychiatric Research Institute, Donald W. Reynolds Institute on Aging, Translational Research Institute, Institute for Digital Health & Innovation and the Institute for Community Health Innovation. UAMS includes UAMS Health, a statewide health system that encompasses all of UAMS’ clinical enterprise. UAMS is the only adult Level 1 trauma center in the state. UAMS has 3,553 students and 1,015 medical residents and fellows. It is the state’s largest public employer with about 12,000 employees, including 1,200 physicians who provide care to patients at UAMS, its regional campuses, Arkansas Children’s, the VA Medical Center and Baptist Health. Visit www.uams.edu or uamshealth.com. Find us on Facebook, X (formerly Twitter), YouTube or Instagram.###