Conceiving in winter raises learning disability risk, study suggests

Conceiving in winter raises learning disability risk, a study of almost half a million children suggests.

The best month in which to conceive in the northern hemisphere is July, according to a study. Picture: iStock

Lack of sun during pregnancy raises the risk that the child will have learning disabilities, ­according to a study of almost half a million children.

Babies in the northern hemisphere conceived in February, March and April, when mothers’ vitamin D reserves have been depleted over the winter, are most likely to have conditions such as autism, dyslexia and ADHD at school age, the ­researchers said.

The best month in which to conceive in the northern hemisphere is July, according to a study that cross-referenced records from 422,500 children with sunlight during their mothers’ pregnancy using NASA ­satellite data.

The intensity of UVB (ultraviolet B) light, needed for ­vitamin D, seemed important.

Researchers at Glasgow University concluded that women who were pregnant when UVB was lowest in Scotland were twice as likely to have a child with a learning disability as those for whom UVB was highest.

Jill Pell, lead author of the study published in Scientific ­Reports, said: “The importance of our study is that it suggests a possible way to prevent learning disabilities in some children. Clinical trials are needed to confirm whether taking vitamin D supplements during pregnancy could reduce the risk.”

The study linked school records with learning disability diagnoses to Scottish maternity records and weather. Eighteen per cent of the 422,512 children had a learning disability, varying from 16.5 per cent of those conceived in July to 21 per cent for February, March and April.

The Times