Plenty of women will tell you that becoming a bit forgetful and emotional is part and parcel of pregnancy.
Now scientists have confirmed that not only does so-called 'baby brain' exist - it actually has a purpose.
According to psychologists, changes in the brain during pregnancy are designed to help mothers prepare for bonding.
A study found that pregnant women show increased activity in the area of the brain related to emotional skills.
The finding suggests that hormones activated during pregnancy fine-tune the intuition which helps a woman understand her baby's needs from the moment the child is born.
Results of the study - led by Dr Victoria Bourne at Royal Holloway, University of London - will be presented at the British Psychological Society's annual conference today in Birmingham.
"Our findings give us a significant insight into the 'baby brain' phenomenon that makes a woman more sensitive during the child bearing process," Dr Bourne said.
"The results suggest that during pregnancy, there are changes in how the brain processes facial emotions that ensure that mothers are neurologically prepared to bond with their babies at birth."
The research team examined the neuropsychological activity of 19 pregnant women and 20 mothers whose babies were nine weeks old on average.
The women looked at images of adult and baby faces with either positive or negative expressions.
The results showed that pregnant women used the right side of their brain more than those who had already had their babies.
The right side of the brain is typically associated with emotion, while the left is linked to logic.
The study used the chimeric faces test, which is based on images composed of half of a neutral face and half of an emotive face combined.
The resulting doctored photo allows researchers to tell which side of the participants' brain is used to process positive and negative emotions.
The results showed that pregnant women used the right side of their brain more than the new mothers did, particularly when processing positive emotions.
"We know from previous research that pregnant women are more sensitive to emotional expressions, particularly when looking at babies' faces," Dr Bourne said.
"We also know that new mothers who demonstrate symptoms of post-natal depression sometimes interpret their baby's emotional expressions as more negative than they really are."
The pregnant women in the study were better at picking up emotions than the mothers whose babies had already been born - and Dr Bourne said further research was needed to explore this.
"It seems the extra sensitivity occurs during pregnancy so that a woman is attuned to her baby straight after the birth.
"It could be said to help develop a mother's intuition so they are very sensitive to the baby's needs."
Dr Bourne suspects the extra sensitivity is triggered by hormones during pregnancy.
"Discovering the neuropsychological processes that may underpin these changes is a key step towards understanding how they might influence a mother's bonding with her baby," she said.
- Daily Mail