The findings are reported as use of cannabis during pregnancy has 'skyrocketed'
Date: September 23, 2020 Source: Washington University in St. Louis
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.
"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."
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.
The data showed children who were exposed to cannabis in the womb (regardless of when that exposure occurred) were slightly more likely to have adverse outcomes. They had elevated psychopathology -- more psychotic-like experiences; more problems with depression and anxiety as well as impulsivity and attention; and social problems as well as sleep disturbance. They also had lower cognitive performance, lower indices of global brain structure during middle childhood as well as lower birth weight.
"Cutting to the chase ... clinicians and dispensaries should discourage cannabis use among those who are pregnant or are considering becoming pregnant.
"However, when we look at exposure after maternal knowledge of pregnancy, which corresponds to when endocannabinoid type 1 receptors are expressed in the fetal brain, the associations with child psychopathology largely remain -- these children tend to have more psychotic-like experiences, more impulsivity and attention problems, and social problems," he said. "This raises the intriguing possibility that prenatal cannabis exposure may plausibly impact child behavior. It in no way shows causation, but documenting that effects are independent of common confounding factors provides incremental support for potential causation."
"Being attentive to substance use problems among family members and providing them with support and access to help is critical for anyone regardless of pregnancy status," Bogdan said. "Learning of one's pregnancy may produce additional reason to stop use. Someone who has just learned of a pregnancy and has previously used cannabis, might think, well I have already exposed the fetus to cannabis, so I may as well not stop. The current data might provide the clinician and parent-to-be with evidence that stopping after learning of the pregnancy may reduce the likelihood of negative outcomes among their children."
From a public health perspective, Bogdan suggested looking to the highly effective public health campaigns and clinician attention directed at reducing the use of tobacco and alcohol during pregnancy. In fact, he said, "This study found that prenatal cannabis exposures were more strongly and consistently associated with adverse child outcomes than prenatal tobacco or alcohol exposure."