What happens if you use marijuana while pregnant? Study finds altered behavior in kids
People who use marijuana while pregnant may predispose their children to mental health and behavioral problems that could leave lasting impacts, according to a new study.
Research on 322 parent-child pairs revealed children whose parents used cannabis during pregnancy — measured by the number of joints smoked per day — were more anxious, aggressive and hyperactive during early childhood than kids of non-cannabis users.
The findings come as legalized recreational marijuana gains a stronger foothold in the U.S., emerging as one of the most used drugs during pregnancy, likely in an attempt to reduce stress and anxiety, researchers note in their study published Nov. 15 in the journal PNAS. Eighteen states and Washington, D.C., have legalized recreational cannabis, while many others have legalized medical marijuana or decriminalized use of the drug. A Nov. 4 Gallup poll found a record-high 68% of Americans believe marijuana should be legal.
Still, the long- and short-term consequences of cannabis exposure to fetuses remain unclear. Therefore, it’s recommended that pregnant people do not use marijuana.
“Pregnant women are being bombarded with misinformation that cannabis is of no risk, while the reality is that cannabis is more potent today than it was even a few years ago,” senior study author Yasmin Hurd, director of the Addiction Institute at the Mount Sinai Health System in New York, and first study author Yoko Nomura, a psychology professor at the City University of New York Graduate Center, said in a news release. “Our findings indicate that using it during pregnancy can have long-term impact on children.”
When children included in the study were between 3 and 6 years old, researchers measured stress hormone levels via hair samples, heart rate variability with electrocardiogram recordings — an indicator of stress — and behavioral traits based on surveys parents completed. The New York City-based study began in 2009.
Parental marijuana use was associated with higher levels of the stress hormone cortisol among kids.
Researchers with the Icahn School of Medicine at Mount Sinai and the City University of New York also analyzed the placentas of some parents shortly after birth and found cannabis use during pregnancy was associated with decreased activity in the genes related to inflammatory responses of the immune system.
The marijuana-related suppression of these genes predicted higher anxiety in children.
What does marijuana exposure do to babies in the womb?
Studies show THC — the psychoactive compound in marijuana that makes users “high” — can be passed from parents’ blood to fetuses through the placenta. Research also shows cannabis chemicals can be passed to babies via breast milk, though such data is “limited and conflicting,” the Centers for Disease Control and Prevention says.
THC is stored in fat, meaning it’s slowly released in the body over time, so babies could still have risk of exposure even after parental marijuana use stops, the agency says.
Existing data shows marijuana use during pregnancy may cause health issues in newborns — such as low birth weight — and give kids learning and attention problems.
Chemicals from marijuana can come from edible products, smoking, vaping and even cannabis-infused creams and lotions, the CDC says. Smoking, in particular, can increase risks for developmental problems in babies because marijuana smoke contains similar chemicals to those found in tobacco smoke.
About one in 20 people in the U.S. use marijuana while pregnant, according to the CDC, and emerging evidence shows the pastime is becoming more common.
A study published in 2019 based on nearly 277,000 women in California found the number of those who used cannabis while pregnant increased from 1.9% in 2009 to 3.4% in 2017 — a year before recreational marijuana officially became legally available for purchase in the state.
“The [new] study results underscore the need for nonbiased education and outreach to the public and particular vulnerable populations of pregnant women regarding the potential impact of cannabis use,” Hurd said in the release. “Disseminating this data and accurate information is essential to improving the health of women and their children.”
This story was originally published November 18, 2021 at 11:01 AM with the headline "What happens if you use marijuana while pregnant? Study finds altered behavior in kids."
