Parents don’t expect their babies to have autism, but they have to make the best of situations. The Public Health Agency of Canada has reported that about one in every 66 Canadian children and adolescents aged 5-17 has autism spectrum disorder (ASD), while previous studies have shown that younger siblings of children with ASD are more likely to be diagnosed with the condition.

A study report from the University of California suggests that use of prenatal vitamins may reduce ASD recurrence in siblings of children with ASD in high-risk families, according to the JAMA Psychiatry journal.

Study participants were recruited from the Markers of Autism Risk in Babies: Learning Early Signs (MARBLES) cohort, and another 241 children whose older siblings had ASD were evaluated. Final data showed a 14.1% prevalence of ASD among children of mothers who took prenatal vitamins during the first month of pregnancy, compared with 32.7% among children whose mothers did not.

Study author Rebecca Schmidt and colleagues believe this to be a benchmark study, but need to further understand how prenatal vitamins reduce the risk of ASD. Prenatal vitamins such as folic acid are known essentials for early brain development and many other pathways that could influence autism risk.

Pediatrics professor Lonnie Zwaigenbaum of the University of Alberta has said the findings demonstrate the potential reduction in absolute risk of autism, which is “remarkable.”

Schmidt has explained that additional research is needed prior to informing public health recommendations for ASD prevention in affected families.