Arts & Sciences School of Medicine

Prenatal cannabis exposure associated with adverse outcomes during middle childhood

There isn't much research looking into the effects of marijuana use on fetuses, but correlations with poor outcomes seem to depend on when, during pregnancy, a fetus is exposed to the drug.(Image: Shutterstock)

While cannabis use during pregnancy is on the rise, researchers at Washington University in St. Louis have found evidence that the resulting children are more likely to have psychopathology in middle childhood.

The team’s analysis are the first steps in studying the effects of cannabis on children as attitudes surrounding its use change rapidly — recreational adult cannabis use is now legal in 11 states and the District of Columbia. Patterns of usage, too, are changing; one of the fastest-growing subsets of cannabis users may come as a surprise: the pregnant.

“There have been increasingly permissive and lenient attitudes toward cannabis use among pregnant people,” said Sarah Paul, a clinical psychology graduate student. “It has skyrocketed in the past few years,” she added, with data indicating a quick rise from 3% to 7% past-month use.


“Unfortunately, despite the increase in use, we know remarkably little about the potential consequences of prenatal cannabis exposure,” Paul said. “Prior studies have linked prenatal cannabis exposure to birth-related outcomes such as lower birth weight and infant characteristics like disrupted sleep and movement. Relatively fewer studies have examined behavior and problems as children age,” and, she said, “findings have been tenuous due to inconsistent replication and an inability to account for potential confounding variables.”


Working with Ryan Bogdan, associate professor of psychological & brain sciences in Arts & Sciences, and director of the Brain Lab at Washington University, and faculty from the School of Medicine, a team of researchers led by Paul and Alexander Hatoum, a postdoc research scholar, poured through data to examine what, if any, effect maternal use of cannabis during pregnancy may have on children.

Their findings were published today in JAMA Psychiatry.

They looked at data from the Adolescent Brain and Cognitive Development Study (ABCD Study), an ongoing longitudinal study of nearly 12,000 children ages 9-11 and their parent or caregiver from 22 sites across the United States that began in 2016.

The researchers grouped participants into three mutually exclusive groups: Children who were not exposed to cannabis prenatally; children who were prenatally exposed to cannabis before the pregnancy was known, but not after; and children who had been exposed to cannabis after the pregnancy was known, regardless of exposure before.

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In addition to Sarah Paul, Alexander S. Hatoum and Ryan Bogdan, Washington University in St. Louis authors on this study include: Jeremy Fine; Isabella Hansen; Allison Moreau; Erin Bondy; Yueyue Qu; and Deanna M. Barch.

Researchers from the School of Medicine include: Emma C. Johnson;  Nicole R. Karcher;  Ebony B. Carter, MD; Cynthia E. Rogers, MD; and Arpana Agrawal