Pregnancy and motherhood may make us all go a little gooey, but it's not turning mums' brains into mush, according to mental health researchers at The Australian National University.

The study – conducted by the Centre for Mental Health Research (CMHR) at ANU – suggests that despite fears mothers may have that pregnancy affects their cognitive functions, there is no evidence to suggest that is true. The findings have been released as part of Mental Health Week.

The research team, lead by CMHR Director Professor Helen Christensen, analysed information from the PATH through Life Project database and found that neither pregnancy nor motherhood had a detrimental effect on cognitive capacity.

The PATH Through Life Project began in 1999 by recruiting and interviewing 2500 young people aged between 20 and 24. The group were subsequently followed up in both 2003 and 2007. After eight years of the study, 223 of the women had become mothers and 76 had been pregnant at the time of the research interview.

"Our research suggests that although women – and their partners – think there may be a link between brain capacity and pregnancy and motherhood, there are certainly no permanent ones that we can find," said Professor Christensen.

"We found no effects of pregnancy on cognitive capacity and motherhood also had no detrimental effects.

"One thing we did observe was that women who have children become marginally less well educated than women who don't have children in their 20s. While this is hardly surprising, as having children will interrupt education, it is something to watch in the future as early mothers may be disadvantaged later on if they do not continue with further training," she added.

Professor Christensen said the study was only able to look at the effects of motherhood over a relatively short time, and she hoped that future human data will align with findings about mother rats.

"Rodent data shows that mother rats have improved multi-skilling capacity and less fear responses than non-mothers. The rat data suggests that mother rats navigate mazes more efficiently, have less anxiety and fear and excel at multi-skilling. That sounds to me like almost every mother I know and I hope that the human effects eventually mirror those findings," she said.