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

Province’s old growth forest report falls short: Nelson scientist

Rachel Holt says province is saving areas that don’t need protection, ignoring those that do

Former Nelson Leafs player, coach passes away

Gary McQuaid played for the Leafs in the 1960s and 70s

Totem pole considered cultural appropriation removed from Nelson’s Hume School

The pole had also become rotted and was seen as dangerous to students

CHECK THIS OUT: Listen up at Nelson Public Library

Avi Silberstein writes about audiobook options at the library

B.C. reports 91 new cases as officials remain worried over ‘clusters of COVID-19

There have now been a total of 8,395 cases in B.C. since the pandemic began

Kootenay yearling released into northern wild

Photos: Scroll to the bottom of the story to see Kenzo’s release

Transgender B.C. brothers debut fantasy novel as author duo Vincent Hunter

‘Transgender people are being misrepresented in popular fiction and media, and we aim to change that’

‘Won’t be gathering for Thanksgiving:’ Trudeau says COVID-19 2nd wave underway

In all, COVID-19 has killed about 9,250 people in Canada

Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Four more cases of COVID-19 in Interior Health

There are 31 active cases in isolation in the health region

Canada’s active COVID-19 cases top 10,000 as daily new cases triple over the past month

Dr. Tam repeated her warning to young people, who have made up the majority of recent cases

First 8 months of fatal overdoses in B.C. have now exceeded 2019 death toll

Nine people died every two days in August, BC Coroners Service data shows

Most Read