New Study Finds That Marijuana Use Harms Babies in the First Trimester of Pregnancy

A new study has found that marijuana use during the early stages of pregnancy has a negative impact on fetal development from the very beginning.

According to lead author Beth Bailey, professor of psychology and director of population health research at the College of Medicine at Central Michigan University in Mount Pleasant, “these findings are especially important — people can often be well into the first trimester and don’t even know they are pregnant.”

She said, “Our study drills down to look very specifically at a specific time point in pregnancy — the first trimester. We found a significant decrease in birth weight of 154 grams. In terms of pounds, it’s about a third of a pound.”

Although losing a third of a pound may not seem like much, Bailey said that such minor weight losses had been connected to health issues as children get older.

“Low birth weight is one of the strongest predictors of a child’s health and development long-term,” she said. “These kids are more prone to developmental delays, higher rates of ADHD (attention deficit hyperactivity disorder), learning disabilities, and have higher rates of emotional problems.”

Because scientists do not currently have the research data to determine whether there is any level of marijuana use that does not cause fetal harm, Bailey stated that while lowering levels of marijuana use during pregnancy is advantageous, it may not be enough to safeguard the development of the child.

“My advice to women is to avoid using marijuana at all during pregnancy and if possible stop using before becoming pregnant,” Bailey said.

According to Brianna Moore, an assistant professor of epidemiology at the Colorado School of Public Health in Aurora, “many pregnant people may use cannabis to treat pregnancy-related symptoms such as nausea and pain or as a ‘substitute’ for prescription medications like antidepressants.”

“However, one study suggests that very few pregnant people (0.5%) use cannabis strictly for medical purposes,” Moore said. “There’s work that needs to be done to understand the contextual, social, or individual factors that influence cannabis use in pregnancy.”

“That would help identify techniques and tools to limit cannabis use in pregnancy,” she added, “such as mindfulness techniques to cope with stress or ‘triggers,’ and over-the-counter medications for nausea and the like.”