Forgetfulness, mental fog and misplaced keys are so common after having a baby there is even a name for it: baby brain.
Researchers say about 80 per cent of mothers report experiencing memory lapses or cognitive fog in the first few months after giving birth.
WATCH THE VIDEO ABOVE: Baby brain might be bunk, new research suggests
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But a major new study suggests the phenomenon may not actually show up in cognitive testing at all.
Researchers from Monash University in Melbourne examined 400 people, including 150 mothers, 150 fathers and 100 non-parents, in one of the largest studies into so-called baby brain to date.
Participants completed tests measuring verbal memory, working memory, processing speed, executive function and subjective memory up to two years postpartum.
“Surprisingly, we found no difference between parents, non-parents, mothers or fathers in the zero to two years post-partum, which was very surprising for us,” researcher Dr Kelsey Perrykkad said.
Researchers found no measurable cognitive decline in parents compared to non-parents across any of the 12 cognitive domains tested.
Even more surprising, they found no difference at any point between zero and 24 months postpartum, despite expectations that the sleep-deprived newborn period would have the biggest impact.
The study also found fathers experienced the same subjective feelings of “baby brain” as mothers.
Male non-parents rated their own memories significantly better than everyone else in the study, including fathers, with researchers suggesting becoming a parent appeared to erase a common male “self-promotion bias”.
Researchers said sleep quality, rather than parenthood itself, appeared to explain much of the perceived memory decline.
“As sleep got worse, subjective memory also declined across the whole sample,” the study found.
Importantly, the testing was carried out in participants’ homes rather than a laboratory setting.
Researchers believed testing parents in their real-life environment, surrounded by distractions and childcare demands, may have been more likely to reveal cognitive changes.
The findings challenge one of parenting’s most enduring stereotypes, with researchers warning the label can have real-world consequences for women in particular.
The paper noted postpartum women are often viewed as “incompetent” or less capable in workplaces and broader society.
Researchers also suggested the expectation of developing baby brain may itself influence how parents interpret normal forgetfulness.
“The powerful social narrative of baby brain … may become a self-fulfilling prophecy,” the paper said.
Still, researchers stressed the experiences reported by parents are real, even if objective cognitive decline could not be measured.
“The balance of evidence to date is in favour of ‘baby brain’ being a subjective experience,” the researchers concluded.
The study was published in the journal Cortex.
