Autism Common Among Babies Conceived in Winter, Scottish Study Claims

Babies conceived during the cold wintry months have more chances of developing autism and other conditions compared to those conceived in summer, says a new study published in the American Journal of Epidemiology.

The study that involved 800,00 school-aged kids in Scotland indicates that the season of conception is responsible for 11.4 percent of autism cases, learning difficulties like dyslexia and intellectual disability. According to Jill Pell, lead researcher and director of the Institute of Health and Wellbeing at the University of Glasgow, says that exposure to influenza and insufficient sunlight-the main provider of Vitamin D, especially during winter pregnancies increases the risk of the diseases.

Studies in the past have found a relation between the risk of autism among kids to the season of conception of birth. A 2011 study by researchers at the University of California found that children conceived in winter are 16 percent more likely to develop autism.

Pell and her team also wanted to find out whether the season of conception is responsible for other developmental conditions. They extracted two Scottish registries, one with school census information and the other having maternity records. The team then linked the month of conception of each child to any particular educational requirements emanating from a diagnosis of intellectual disability, autism, difficulties in learning, hearing or vision impairments, motor delays or communication problems.

It was found that 8.9 percent of babies conceived in winter, between January and March, suffer from intellectual disability, learning difficulties, or autism compared with 7.6 percent of those conceived between July and September.

They also found the highest rate of intellectual disability and dyslexia was highest among kids conceived in February while it was lowest for those conceived in August. However, the absolute danger of autism is tiny since on an average, 1 percent of babies conceived in winter have autism while the figure for those conceived in the warm months is 0.9 percent.