Kids whose moms use weed during pregnancy more likely to have psychotic-like behaviors, social problems: Study
Cannabis use during pregnancy is on the rise, and researchers have found that using marijuana while pregnant may increase the risk of psychotic-like behaviors and other problems in children. They found that children who were exposed to weed in the womb — regardless of when that exposure occurred — were more likely to have adverse outcomes during middle childhood. They had elevated psychopathology — more psychotic-like experiences, more problems with depression and anxiety, impulsivity and problems with attention, social problems as well as sleep disturbance. The children also had lower cognitive performance, lower indices of global brain structure during middle childhood as well as lower birth weight.
If the woman continued to use after she discovered she was pregnant, the negative effects were more pronounced, according to the study published in JAMA Psychiatry. Based on their findings, the authors suggest that clinicians and dispensaries should discourage cannabis use among those who are pregnant or are considering becoming pregnant. “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,” explains study author Ryan Bogdan, associate professor of psychological and brain sciences, and director of the Brain Lab at Washington University in St Louis. He adds, “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.”
From a public health perspective, the study suggests looking at effective public health campaigns and clinician attention directed at reducing the use of tobacco and alcohol during pregnancy. “This study found that prenatal cannabis exposures were more strongly and consistently associated with adverse child outcomes than prenatal tobacco or alcohol exposure,” says Bogdan.
Cannabis use in the US
Recreational adult cannabis use is now legal in 11 states and the District of Columbia. Cannabis use more than doubled among pregnant women in the US during 2002-2017, according to data collected from 467,100 women aged 12-44 who participated in the National Survey on Drug Use and Health (NSDUH). Between 2002-2003 and 2016-2017, past-month cannabis use increased from 3.4% to 7% among pregnant women overall and from 5.7% to 12.1% during the first trimester. The analysis also shows that daily or near-daily cannabis use in the past month increased from 0.9% to 3.4% among pregnant women overall, from 1.8% to 5.3% during the first trimester, from 0.6% to 2.5% during the second trimester, and from 0.5% to 2.5% during the third trimester.
“There have been increasingly permissive and lenient attitudes toward cannabis use among pregnant people. It has skyrocketed in the past few years. Unfortunately, despite the increase in use, we know remarkably little about the potential consequences of prenatal cannabis exposure,” says study author Sarah Paul, a clinical psychology graduate student.
What did the researchers find?
Accordingly, for their analysis, the team 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 US that began in 2016. The investigators 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. Among 11,489 children, 655 (5.7%) were exposed to cannabis prenatally. The researchers found that children whose mothers had used weed during pregnancy were more likely to have psychotic-like experiences.
“Prenatal cannabis exposure may increase the risk for psychopathology. Relative to no exposure, cannabis exposure only before (413 or 3.6%) and after (242 or 2.1%) maternal knowledge of pregnancy were associated with greater offspring psychopathology characteristics (that is, psychotic-like experiences and internalizing, externalizing, attention, thought and, social problems), sleep problems, and body mass index, as well as lower cognition and gray matter volume. Only exposure after knowledge of pregnancy was associated with lower birth weight as well as total intracranial volume and white matter volumes relative to no exposure and exposure only before knowledge,” the findings reveal.
According to the research team, 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. “Learning of one’s pregnancy may produce an 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,” emphasizes Bogdan.
The experts stress that it is also important not to stigmatize expecting parents who may be experiencing difficulties. “Quitting substance use during pregnancy, which is already a challenging time, may not be straightforward. Physician support and empirical paradigms for quitting during pregnancy will be important. Couples who are planning to have a child may wish to consider combatting cannabis use before they begin attempting to conceive and the additional stressors of pregnancy begin to mount,” recommends Bogdan.