As childhood obesity rates continue to rise in the U.S., researchers are looking into why. A new study funded by the National Institute on Drug Abuse and published in the journal of Pediatric Obesity exposes one of the possible causes – prenatal exposure to both tobacco and cannabis smoke.

Children whose mothers smoked both tobacco and cannabis while pregnant had a 12 times higher risk for obesity by middle childhood (9-12 years) compared to non-exposed children, reported Medical Express.

"Two of the most commonly used substances during pregnancy are cigarettes and cannabis, and they are often used together," said Rina Das Eiden, professor of psychology and a study author. "While we know about the risks of prenatal tobacco exposure and child obesity, less is known about co-exposure to tobacco and cannabis. We wanted to examine a potential relationship between prenatal co-exposure and obesity risk from birth to middle childhood."

The scientists analyzed the difference in obesity development from birth to mid-childhood among children whose mothers used only tobacco, and both tobacco and marijuana while pregnant. They compared children in the study to a demographically similar group of non-exposed children.

"We found that children in both exposure groups had a steeper increase in BMI trajectories from birth to mid-childhood, but among co-exposed children, girls had a steeper BMI increase compared with boys of the same age," said Kai Ling Kong, associate professor of pediatrics at Children's Mercy Hospital Kansas City and the University of Missouri-Kansas City School of Medicine, another study author. "Overall, we found 12 times higher odds of having obesity among those co-exposed than those non-exposed to tobacco and cannabis. Children in the co-exposed group also had significantly greater fat mass and fat mass percent compared with non-exposed children. Children exposed only to tobacco were not different in fat mass compared to non-exposed children."

The authors noted that further research is needed to confirm if other factors also contributed to these findings.

Kong concluded, "In the future, more research also needs to be done on children exposed to cannabis only to understand if co-exposure results were due to cannabis or a combination of both tobacco and cannabis use."

Related Links: 

Is It Safe To Use Cannabis While Pregnant? New Study Suggests It Can Cause Aggression & Anxiety In Children

Why Simultaneous Use Of Marijuana & Alcohol During Pregnancy Is Risky, New Research Paper Explains

Using Marijuana While Pregnant May Lead To Mental Health Problems In Children: New Evidence

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