A new pilot study found that the prevalence of autism among children prenatally exposed to alcohol was significantly higher than the prevalence in the overall Canadian population.

The study, which will be presented at the Canadian Paediatric Society’s annual conference in P.E.I. this week, examined the case reports of 300 Ontario children aged three to 16 who were exposed to alcohol in the womb.

Researchers reviewed the case reports to determine the prevalence of autism, number of children diagnosed with fetal alcohol spectrum disorder (FASD), and other demographic data.

FASDs are a group of conditions that can present in children whose mother drank alcohol during pregnancy, and are among the leading causes of cognitive and developmental disability among Canadian children. FASD symptoms can range from mild to severe, and may include physical, mental, behavioural, and learning disabilities.

The researchers found that 4.7 per cent (or 14) of the 300 children had been diagnosed with autism. By comparison, the prevalence of autism among the general Canadian population is 1.1 per cent.

The study also found the following:

  • Of the 14 children who were diagnosed with autism, half were boys and half were girls;
  • Two additional children had autistic features, but did not meet the criteria for a formal diagnosis;
  • Of these 16 children, all were diagnosed with FASD.

Dr. Brenda Stade, co-author of the study and head of St. Michael's Hospital Fetal Alcohol Spectrum Disorder Clinic, told CTVNews.ca that researchers aren't sure what's behind the association between prenatal alcohol exposure and autism.

"Whether alcohol is actually causing autism symptoms, we don't know," she said. "We can only say that there's a correlation, but we don't know exactly why."

Stade noted that there may be some overlap between FASD symptoms and the symptoms associated with autism. However, she said, children diagnosed with autism in the study presented with symptoms of both disorders.

She recommends that children who are being screened for FASD should also be screened for autism to ensure they're getting every available intervention.

"We don't want to miss those kids who could benefit from specific interventions developed for autism,” she said.