Pregnant women are more likely to get confused and lost when they drive because of 'baby brain'

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Pregnant women are more likely to get lost when they drive as a result of 'baby brain', new research suggests.

Key areas of the brain involved in helping people find their way around were smaller during the last month of pregnancy, a study found.

This affects their ability to navigate and means they are more likely to get confused on a journey, scientists claim. 

Experts say changes in the levels of the hormone oestrogen during pregnancy appear to alter the structure of parts of the brain, changing how expectant women think. 

Key areas of the brain involved in helping people finding their way around were smaller during the last month of pregnancy, a study found

Researchers from the Max Planck Institute for Human Development in Berlin, Germany assessed the performance of 30 women in the final month of pregnancy in a series of tasks. 

They were compared to 30 women - all aged in their 20s - who were not expecting a baby and had never been pregnant before.

They were asked to perform memory tests, spacial orientation and a navigation task that required them to find their way around a maze after first being shown the correct path.

There was no difference between the groups in memory or the other cognitive tests.

But the pregnant women were less accurate when navigating than those who were not expecting a child.

The researchers also took brain scans of the women and found a part of their brain known as the putamen, which is involved in learning, was smaller in those who were pregnant.

Lead researcher Dr Nina Lisofsky said it was difficult to say what impact this could have on women in the real world, but it could mean some tasks like following directions could get harder.

This affects their ability to navigate and means they are more likely to get confused on a journey, scientists claim

They found while pregnant women were less accurate when using a form of route finding known as egocentric navigation.

But they were just as accurate as other women when using another form called allocentric navigation.

Egocentric navigation, which is most common among women, involves using local landmarks to follow a route and uses directions from their own point of view like left and right.

Allocentric navigation is more common among men and uses more abstract ways of visualising a route, such as giving distances between turns and using points on a compass to describe direction.

She said: 'Pregnancy is a period in life in which women are exposed to exceptionally high oestrogen levels.

'Oestrogen does act on different brain regions and thus, hormonal influences during pregnancy might be related with neural change.

'We found that women's route learning performance was altered during pregnancy.

'The observed behavioral differences are relatively subtle, so they might not go along with any behavioral impairment in normal life of women.' 

She added that the findings appear to support evidence for the impacts that baby brain can have on women in everyday life.

She said many areas of women's brains tend to change shape during pregnancy. 

The study was published in the journal Neurobiology of Learning and Memory.