A New Zealand researcher has been granted more than NZ$100,000 to investigate the effects of cannabis smoking during pregnancy on the genes of children. 

Unlike with substances such as alcohol and tobacco, there is a limited body of literature on the effects of cannabis on offspring exposed while in utero.

Dr Amy Osborne

Genomics researcher at the University of Canterbury’s School of Biological Science Dr Amy Osborne’s told The Spinoff pregnant people in the US are using cannabis to combat morning sickness and appetite loss.

However, she warned: “They think that that’s okay, but we just don’t know. It’s sort of touted as something that’s ‘safe’, in inverted commas.” 

The study will use DNA samples from people whose maternal parent smoked cannabis during pregnancy and will be sampling from the Christchurch Health and Development Study (a 40-year study comprised of 1,265 now-adults) and from a group in the UK.

The samples will be analysed for particular chemicals that sit on strands of DNA that control how genes for brain development are turned on and off. This will be compared with DNA from children whose maternal parent did not use cannabis during pregnancy. 

The study builds on previous research by Osborne and her team which found that smoking tobacco during pregnancy could be linked to behavioural problems for the child later in life.

She said: “We can see these associations in the neurodevelopment of the baby for tobacco smokers, but does cannabis tell the same story?” 

However, she insisted her team are not on “one side of the fence”.

“We’re not trying to say it’s bad or there’s no problem at all. It’s about building those incremental knowledge gains so that we have the power to make those calls and people can educate themselves.”

While future research is yet to be funded, Osborne hopes her team will next conduct an experimental study where a lab model of human brain cells will be created and dosed with THC and CBD to look for similar effects on epigenetics.

Osborne added: “We can then try and show a bit of cause and effect. The thing with all these [other] studies is that you can show associations, but you can’t show the functional side [of how it works].” 

While there are many observational studies that have investigated cannabis use and pregnancy, the findings often contradict each other. This area of research also remains complicated as many of the health effects of smoking cannabis can be disturbed when tobacco or alcohol are also used.  

Hannah Adler

Hannah is a communications professional and early-career researcher in the disciplines of health communication and health sociology. She is a PhD student at Griffith University currently writing a...