Marijuana Use in Pregnancy Linked to Autism in Babies, New Study Finds

Any woman who uses marijuana and finds out that she is pregnant should immediately discuss its use with her doctors, experts say.

(CNN) - In what they qualify as the largest study ever conducted, researchers found that using marijuana during pregnancy can increase a child's risk of developing autism.

"Women who used marijuana during pregnancy were 1.5 times more likely to have a child with autism," said study author Dr. Darine El-Chaâr, a maternal-fetal medicine specialist and clinical researcher at the Institute. Research Department of the Ottawa Hospital in Canada.

These are not reassuring findings. We strongly discourage the use of cannabis during pregnancy and breastfeeding, ”she said.

Previous studies have shown that marijuana use during pregnancy is linked to low birth weight, impulsivity, hyperactivity, attention problems, and other cognitive and behavioral problems in children, according to the Centers for Disease Control and Prevention. Diseases of the United States (CDC). Women who use marijuana, according to a study, have a 2.3 times higher risk of having a stillborn childbirth.

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"Based on that, I am not too surprised by these findings," El-Chaâr said. "Fetal brain development occurs throughout all gestation ages," he explained.

The study, published Monday in the journal Nature , reviewed information on all births in Ontario, Canada, between 2007 and 2012, long before recreational marijuana use was legalized in the country in 2017. Out of half a million Of women in that data group, the researchers narrowed the study to 2,200 women who said they used only marijuana during pregnancy, not mixing it with tobacco, alcohol or opiates.

The study did not capture the amount and type of marijuana that women used during pregnancy. She also did not know when during pregnancy and how often women used it. And while the study was only able to show association, and not cause and effect, the researchers said they did their best to eliminate potential confounders.

Marijuana use during pregnancy grows

As cannabis becomes legal and more socially accepted, health researchers worry that expectant moms think it's okay to use it to treat morning sickness or recreationally, despite a lack of research on long-term impacts on the fetus.

Women also choose to use marijuana to avoid medications that they believe may be more harmful to their babies, such as anti-nausea pills, antipsychotic medications and opiates, a small study of pregnant women by researchers at Washington State University found.

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El-Chaâr said that according to what she hears from expectant mothers, pain management is the most common cause for marijuana use.

"It helps with different conditions that you may have or for nausea and vomiting in pregnancy," El-Chaâr said. “Some people (said) they use it to sleep or to reduce stress. Others use it recreationally; it's just part of their routine, ”he explained.

The use of marijuana by pregnant women has grown in the United States in recent decades. An analysis last year of more than 450,000 pregnant women between the ages of 14 and 44 by the National Institute on Drug Abuse found that cannabis use more than doubled between 2002 and 2017.

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Most of the marijuana use was during the first three months of pregnancy, according to the study, and was more recreational than medical. However, the first trimester can be one of the most sensitive times for fetal brain development, when it is most susceptible to damage, El-Chaâr said. Studies have found receptors for cannabis in the brains of animals starting at five and six weeks of gestational age, he explained.

"It can be hypothesized that if there are cannabinoid receptors and the baby's brain is exposed, it may have (an) effect on brain development," he said.

What to do

Any woman who uses marijuana and finds out that she is pregnant should immediately discuss its use with her doctors, experts say. However, many women are not honest, research shows. A study of women 24 and younger found that they were twice as likely to test positive for marijuana use than they were when they reported their status themselves.

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The self-reported prevalence of marijuana use during pregnancy ranges from 2% to 5% in most studies, according to the American College of Obstetricians and Gynecologists.

"Women who are pregnant or considering the possibility of becoming pregnant should be encouraged to stop using marijuana for medicinal purposes in favor of an alternative therapy for which there is better specific safety data for pregnancy", states the College in its recommendations.

"There are insufficient data to assess the effects of marijuana use on children during lactation and breastfeeding, and in the absence of such data, marijuana use is discouraged," he adds.

Autism pregnancy