Rachel Moseley

A study published in The BMJ suggests that the incidence of autism spectrum disorder (ASD) is comparable between boys and girls. The study included a sample of more than 2.7 million people born in Sweden between 1985 and 2020 who were followed from birth to a maximum age of 37. More than 78,000 were diagnosed with ASD. It was observed that boys are usually diagnosed between the ages of 10 and 14, five years earlier than girls. By the age of 20, the proportion of diagnoses is almost equal between the sexes. Before the age of 10, the ratio is 3:1 in favour of boys.

A team has analysed estimated data on exposure to pollution during and after pregnancy and its possible link to a diagnosis of autism in more than two million births in Canada between 2002 and 2022. Their findings are that greater exposure to small PM_2.5 particles containing sulphate or ammonium is associated with a higher likelihood of receiving a diagnosis of autism in the first five years of life. A slightly increased proportion was also observed with greater exposure to ozone during certain weeks of pregnancy and in the first year of life. The results are published in the journal JAMA Network Open.