Oct. 29, 2024 – Using cannabis during pregnancy may have a negative impact on some areas of a child’s development.
A study involving 250 children in Ohio shows that exposure to cannabis during pregnancy was linked to lower performance at age 5 on assessments of thinking skills, impulse control, attention, and planning, compared to 5-year-olds who weren’t exposed to the drug during pregnancy. The researchers also reported increased aggression among the children exposed to cannabis.
Cannabis use was determined based on one of three things: urine test results that were provided by people in the study, the mother's reported cannabis use during pregnancy, or a listing in the mother’s medical records during pregnancy. The urine test looked for metabolites of tetrahydrocannabinol (THC), which is present in marijuana and products known as delta-9.
Up to 7% of pregnant people report using marijuana during pregnancy nationwide, noted the authors of the study, which was published this week in the journal JAMA Pediatrics.
Mothers were enrolled during the first or second trimester. Parents making plans to deliver their babies at Ohio State University Wexner Medical Center were asked at the time to enroll in a pregnancy research program. The babies were born between 2010 and 2016. And when they were 5 years old, they were invited, with their caregivers, to take part in the follow-up portion of the study. Eighty of the 250 children in the study were exposed to marijuana during pregnancy, which is 32% of children in the study.
Exposure to tobacco, other drugs, and alcohol was also common, ranging from 22% to 39% of children in the study. The researchers adjusted for other drug exposures and factors to focus specifically on cannabis use during pregnancy.
At 5 years old, the children took part in numerous assessments, such as an interactive activity on a tablet that measures a child’s attention and ability to focus. One of the other assessments, which evaluated aggression, is based on whether or not a child hit a toy doll’s head.
Caregivers also reported on the children’s behavior and abilities, but there were no differences between those reported by caregivers of children exposed to cannabis during pregnancy, and those who were not exposed.
“Although cannabis is a natural product, there are still many risks to using it during pregnancy,” said researcher Sarah Keim, PhD, of the Center for Biobehavioral Health at Nationwide Children’s Hospital in Columbus, OH, according to a news release. “Some women may turn to cannabis to help deal with some common issues of pregnancy including nausea, sleep problems and stress. This is not recommended. Consulting with a health care provider to find safer options to help with these issues during pregnancy is important.”
An editorial published alongside the study noted important limitations of the study, including that it was small in size, was limited to one hospital, and the people in the study were primarily Black and lived in poverty (for example, having a two-person household income of less than about $17,000 per year, or four-person household income of less than $26,000 per year).
The authors of the editorial also noted that “it is well recognized that adverse exposures often co-occur and exist in a network of many other environmental and lifestyle factors,” making research about a specific factor, such as cannabis exposure during pregnancy, very challenging.
“One particular aspect that should be considered in regard to the developing brain is that the child’s environment is largely dependent on the caregiver, from the utero prenatal exposures to postnatal environment and parenting through infancy and early childhood. These are key factors underlying intergenerational effects on brain and behavior,” they concluded, suggesting that mothers who use cannabis during pregnancy be identified as potentially benefiting from mental health and social supports that may ultimately lead to benefits for their children.
