Women who experience depression during pregnancy are more likely to have an unhealthy diet, and this can negatively impact on their children’s cognitive functioning in later life, new research has claimed.

The study, published online by the British Journal of Psychiatry, was led by Dr Edward Barker of the Institute of Psychiatry, King’s College London. The research team studied 6,979 women and their children who were part of the Avon Longitudinal Study of Parents and Children in the UK.

For this study, the women were assessed for symptoms of depression on five occasions between when they were 18 weeks pregnant and when their child was 33 months old. The women were asked to complete a food questionnaire to assess their eating habits when they were 32 weeks pregnant and again when their child was 47 months old. The children’s cognitive function was assessed when they were 8 years old.

The researchers found that women who had symptoms of depression during pregnancy were more likely to have unhealthy diets that were high in saturated fat, trans fat, salt and added sugar. The children of these mothers had lower scores on the tests for cognitive functioning at age 8.

“Our study provides evidence that prenatal maternal depression symptoms relate to both increased unhealthy and decreased healthy prenatal diets which, in turn, is associated with reduced child cognitive function,” said Barker. “During pregnancy, the diet of the mother directly influences the nutritional environment of the foetus, which presumably will affect the development of the foetal nervous system including the brain.”

The researchers point out that their research does not show a causal relationship between prenatal depression and children’s cognitive functioning – only a correlation. But they believe the findings show the importance of encouraging women who are depressed during pregnancy to eat more healthily.

“Helping women adopt a healthier diet during pregnancy could be highly effective in reducing the association between reduced cognitive functions in children and prenatal maternal depression,” Barker added.

Reference: Barker ED, Kirkham N, Ng J and Jenson SKG (2013) Prenatal maternal depression symptoms, prenatal nutrition and child cognitive function. British Journal of Psychiatry, bjp.bp.113.129486, ePub ahead of print, 10 October 2013