A study published in the Journal of the American Medical Association in mid-September found that cannabis use during pregnancy increases a child’s susceptibility to developing psychiatric symptoms — such as aggression — later in life.

The question about the negative side effects of cannabis for pregnant women and their children has been a hard one to answer even before marijuana started becoming legalized in the United States.

If you went back a few years and googled, “Is cannabis safe to use during pregnancy?,” you’d have found a lot of inconclusive results and contrary opinions swarming from sources ranging from dispensaries to medical professionals.

Some would have called it safe, even beneficial to use, while others would have argued that it was harmful.

Professionals have more recently cautioned that the side effects of using cannabis during pregnancy are unknown and the Centers for Disease Control and Prevention recommends that pregnant women not use it for that very reason. But before this year, more uncertainty than certainty surrounded questions about the specific effect of cannabis during pregnancy on infants later in their life.

“It’s easy to say, because of the lack of research, that (cannabis) is not harmful,” said Dr. David Baranger, the lead analyst and author of the new study from Washington University of St. Louis. “(Our) research is important because it’s showing that (cannabis) isn’t just simply a neutral substance in terms of the offspring’s mental health.”

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Cause for alarm?

The findings come from the largest study of adolescent brain development to date, referred to by professionals as the ABCD Study, which includes children between the ages of 9 and 18. It offers deep insight into their development from before birth to adolescence.

Baranger and his team analyzed and followed their subjects’ records using two years’ worth of data between the ages of 10 to 12. He said they found “reasonable suspicion that cannabis use during pregnancy is not benign for the offspring” and can make a child even more prone to symptoms of mental illness when they reach “peak vulnerability during later adolescence.”

While the study did not diagnose specific mental illnesses, Baranger said psychiatric illness symptoms were measured.

“We see effects for aggressive behavior, rule-breaking behavior, social problems and attention problems like with ADHD,” he said.

These symptoms were more prominent in adolescents whose mothers self-reported cannabis use during pregnancy. The researchers said they believe cannabis use among mothers is underreported.

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Pregnant women sometimes use cannabis for a reprieve from pain, discomfort, nausea and to relieve symptoms of mental illness, among other reasons, per the National Institute of Drug Abuse.

During the pandemic, cannabis sales skyrocketed, according to a study in the Journal of the American Medical Association by Kelly C. Young-Wolff and her colleagues at Kaiser Permanente Northern California in Oakland. During the pandemic lockdown, cannabis usage among pregnant women increased 25% and reached about 8% or 1 in 12 pregnant women. It had already been rising since 2017, even before COVID-19.

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More research needed

Colorado is well-known for its legalization of marijuana.

Recreational dispensaries in Colorado are not allowed to give medical advice and they can’t stop a woman from buying because she is pregnant. At medical dispensaries, it is legal for distributors to recommend or discourage usage while pregnant.

An employee at a medical marijuana dispensary in Colorado Springs told Deseret News that if a pregnant woman comes in wanting recommendations for cannabis use during pregnancy, she usually suggests edibles.

With cannabis legalization becoming more common across the country, Baranger said more hands-on research is essential to protect both mother and child and says that the public can expect more information soon.

The new study is a stepping stone effort to two other projects that the University of Washington in St. Louis is working on regarding cannabis use in pregnancy.

The University’s Dr. Ryan Bogdan said he and his colleagues are now recruiting pregnant women to assess what happens “throughout pregnancy and their children shortly after birth so that we may understand neonatal associations with prenatal cannabis exposure.”

Bogdan said he hopes their future findings will be used to “help guide public policy and individual choices.”

Since marijuana has been legalized by multiple states, there’s still a lot that is unknown about its effects, including on fetuses and pregnant women. Ongoing research hopes to reveal the dangers and side effects caused by the drug, he said.