A handful of cannabis bud is shown in Fenwick, Ont., on Tuesday, June 26, 2018. THE CANADIAN PRESS/Tijana Martin

Researchers find cannabis use in pregnancy linked to greater risk of autism

Researchers caution findings only show association — not cause and effect

A new study links cannabis use in pregnancy to a greater risk of autism.

Researchers including experts from the Ottawa Hospital and the University of Ottawa reviewed data from every birth in Ontario between 2007 and 2012, before recreational cannabis was legalized.

They found 1.4 per cent of 18-month-olds were diagnosed with autism but that rate was higher among children exposed to cannabis in the womb, at 2.2 per cent.

RELATED: New study suggests autism overdiagnosed: Canadian expert

RELATED: Surf’s Up Tofino offers wave of positivity for families living with autism

Of roughly 500,000 women in the study, 3,000 reported cannabis use during pregnancy. The analysis focused on 2,200 women who said they only used cannabis during pregnancy, and no other substances.

Researchers don’t know how much cannabis was used, how often, at what stage of their pregnancy, or how it was consumed. They also caution the findings only show association — not cause and effect.

The findings were published today in the medical journal Nature Medicine.

Even though recreational cannabis is now legal and more socially acceptable, study co-author Dr. Darine El-Chaar says that doesn’t mean it’s safe for people who are pregnant or breastfeeding.

El-Chaar says cannabis use seems to be more prevalent, with her patients much more open about telling her it helps ease their morning sickness or pain.

“Our answer is still that we don’t have correct, properly made studies that are designed to look at this question,” says El-Chaar, a maternal-fetal medicine physician and clinician investigator at the Ottawa Hospital and assistant professor at the University of Ottawa.

Researchers had previously found that cannabis use in pregnancy was linked to an increased risk of preterm birth. That study also found pregnant women who used cannabis often used other substances including tobacco, alcohol and opioids.

Funding came from the Canadian Institutes of Health Research.

— By Cassandra Szklarski in Toronto

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Blaze takes commercial building in Louis Creek Industrial Park

Firefighters, paramedics and RCMP from Barriere and Chu Chua were on scene

Unofficial holidays: Here’s what people are celebrating for the week of Sept. 27 to Oct. 3

World Farm Animals Day, Drink Beer Day and Virus Appreciation Day are all coming up this week

Two new COVID-19 cases reported in Interior Health

The total number of Interior Health cases since the beginning of the pandemic is now at 522

District of Barriere Utilities Manager reports to council on Barriere wells

District of Barriere Utilities Manager Ian Crosson presented a verbal report during… Continue reading

A victory year for Barriere Blooms

Barriere was blooming this summer. Despite the COVID-19 pandemic, residents and businesses… Continue reading

QUIZ: Do you know what’s on TV?

Fall is normally the time when new television shows are released

Canadian ski resorts wrestle with pandemic-vs.-profit dilemma as COVID-19 persists

Few are actually restricting the total number of skiers they allow on the hill

Victoria-area RCMP locate high-risk sex offender thanks to help of taxi cab driver

Scott Jones wanted on a Canada-wide warrant, ‘a risk to women and girls,’ police say

A (virtual) walk around the world by 88-year-old B.C. man

George Doi says it’s simple: ‘I like walking’

End of CERB means uncertainty for some, new system for others

As of a week ago, the CERB had paid out $79.3 billion to 8.8 million people

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Horgan, Wilkinson trade barbs over MSP premiums, health care at campaign stops

Horgan called a snap election for Oct. 24 earlier this week

PHOTOS: 2nd calf in a month confirmed among Southern Resident killer whale pod

Center for Whale Research said they will eagerly await to observe the calf to evaluate its health

Most Read