Most Americans and Canadian have have access to some sort of legal marijuana, whether for medical or recreational use, and there’s a growing acceptance of using marijuana. However, a new study indicates that using marijuana during pregnancy even once a week can have long-term effects on the mental well-being of babies.
The study, published in the Journal of The American Medical Association (JAMA) Psychiatry, followed 11,489 children ages 9-11. Of those, 655 had been exposed to marijuana in utero, as reported by the kids parents’ or caregivers. In total, 5.7% of the kids were exposed to marijuana; 3.6% only before their mothers knew they were pregnant, and 2.1% even after mom knew she was expecting.
The researchers compared the kids who had been exposed to marijuana to those who hadn’t, using a variety of health metrics. They found that any exposure to cannabis in utero was associated with mental health problems including problems with attention and thought processes. Kids who had been exposed had more sleep trouble, BMI issues and less gray matter in their brains.
Kids who were exposed to marijuana even after the mothers knew they were pregnant had lower birth weights, less brain volume, and less white matter in their brains compared with kids who weren’t exposed and those whose exposure stopped when the mom learned she was pregnant.
The study authors indicated that the research should make women think twice about their cannabis use.
“Currently, pregnant women, and even those contemplating pregnancy, should be discouraged from using any cannabis by health care professionals, dispensaries, and others; women refraining from cannabis use during pregnancy may benefit offspring,” they wrote.
The study comes as more women are using marijuana during their pregnancy. A study published last year found that marijuana use during pregnancy doubled between 2003 and 2017. Overall, 7% of women reported using cannabis while they were pregnant. During the first trimester, marijuana use was as high as 12.1%, since many women turn to cannabis to help control nausea associated with pregnancy.
It’s important to note that the study established correlation (a link), not causation. The researchers pointed out that other factors that contribute to marijuana use could also be associated with mental health troubles in kids. For example, moms who are biologically predisposed to attention trouble might be more likely to use marijuana during pregnancy. Their kids, in turn, have two increased risk factors for mental health troubles.
Another study, published last month, found that pregnant women who used marijuana were more likely to have children who have autism.
“Women who used cannabis during pregnancy were 1.5 times more likely to have a child with autism,” study author Dr. Darine El-Chaâr, a maternal fetal medicine specialist and clinical investigator at Ottawa Hospital Research Institute in Canada, told CNN. “These are not reassuring findings. We highly discourage use of cannabis during pregnancy and breastfeeding.”
Last year, in response to the research about rising rates of marijuana use among pregnant women, the surgeon general released a warning about pregnant or nursing moms using pot. The warning pointed out that some dispensaries even recommend marijuana to people who experiencing morning sickness.
Even after a baby is born, the Surgeon General recommends that parents avoid using pot, particularly around their kids or while nursing.
“Maternal marijuana use may still be dangerous to the baby after birth,” the warning said. “THC has been found in breast milk for up to six days after the last recorded use. It may affect the newborn’s brain development and result in hyperactivity, poor cognitive function, and other long-term consequences.”