New research on prenatal care suggests that a mother-to-be's diet during pregnancy can have a massive impact on her baby's developing brain. Unhealthy eating during pregnancy may reduce the brain power of children later on in life.

Involving 6,979 women and their children, the new study from researchers at King's College London and Canada (known as the Avon Longitudinal Study of Parents and Children in the UK or the "Children of the 90s" study), assessed new moms for symptoms of depression five times between when they were 18 weeks pregnant and when their babies were 33-months-old.

Participating mothers were also asked to complete food questionnaires about their eating habits when they were 32 weeks pregnant and again when their babies were 47-months-old.

When the children were eight-years-old, the researchers assessed their cognitive abilities with a series of performance and verbal-based IQ tests.

The researchers found that women who were depressed during their pregnancy were more likely to eat processed and junk food with unhealthy levels of fat and trans fats. Meanwhile, healthy eating during pregnancy was defined as diets rich in nutrients and low in salt, sugar and fat.

Babies whose mothers had eaten unhealthy diets during pregnancy were more likely to score lower on the IQ tests than those of babies whose mothers ate more healthfully, leading the research team to draw a link between prenatal diet and the development of the fetal nervous system, including the brain.

"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," study lead author, Edward Barker, of the Institute of Psychiatry at King's College London, said in a press release.

"During pregnancy, the diet of the mother directly influences the nutritional environment of the fetus, which presumably will affect the development of the fetal nervous system including the brain."

Barker added that there is only a correlation between poor diet during pregnancy and children's cognitive functioning, not a direct causation, and it is possible that poor eating is a sign of stress, a factor which also affects the brain development of fetuses and by changing the way that the body processes beneficial vitamins.

He hopes that the latest findings, published online in the British Journal of Psychiatry, help encourage women to seek treatment for their depression while pregnant and adopt healthier prenatal diets.