The so-dubbed "baby brain" is a real, measurable phenomenon, which many women proved to experience during pregnancy, researchers at Australia’s Deakin University have found.
They found empirically that general cognitive and executive functioning, which comprises attention to detail, ability to plan and solve problems, are virtually poorer in pregnant women than in non-pregnant controls.
Only in the third trimester? Damn I've been using baby brain as an excuse for 7 years 🤔— Melissa MacKenna (@melmac203) 15 января 2018 г.
"General cognitive functioning, memory, and executive functioning were significantly reduced during the third trimester of pregnancy, but not during the first two trimesters," the authors stated.
Overall, the analysis performed by PhD candidate Sasha Davies and her colleagues included a total of 709 pregnant women and 521 non-pregnant controls.
Cognition Still Normal
To avoid hasty interpretations, they said that overall cognition remains up to the norm basically throughout a pregnancy; women are capable of doing their job and pursuing their daily routines.
"These findings need to be interpreted with caution, particularly as the declines were statistically significant, but performance remained within the normal ranges of general cognitive functioning and memory."
"[M]ore significant consequences (e.g., reduced job performance or impaired ability to navigate complex tasks) are less likely," Dr. Melissa Hayden, the study's co-author, said.
Still, researchers say some changes are observed between the first and the second trimesters, and they peak further in the third trimester, often making women lose, to some extent, attentiveness and abstract thinking skills — changes "noticeable to the pregnant women themselves and perhaps by those close to them."
The reported differences are consistent with the earlier findings of long-term gray matter reductions registered throughout pregnancy.
"It looks like the reason pregnant women see a reduction in grey matter is because they're probably recruiting those areas to more important areas associated with the business of child rearing — so things like bonding, and social cognition," senior author Associate Professor Linda Byrne said.
It still remains to be seen what causes the reported changes and whether the same applies to multiple pregnancies.
Disputes Over 'Momnesia'
The aforementioned study, published in the Medical Journal of Australia, attempts to settle the long-standing debate on whether a mental fog, experienced and reported by mothers-to-be, actually exists. For instance, many women have complained that they were less verbally fluent and coherent at work, less attentive to detail and tended to forget appointments, saying they felt some cognitive impairment.
According to an older and highly reputable study, between 50 and 80 percent of women say that they have experienced one of these.
Despite multiple accounts of that kind, some studies dismissed the "mental fog" during pregnancy as nothing but a myth, saying the differences occur due to general tiredness rather than actual changes in brain capacity. A number of researchers, though, backlash, saying reductions in the brain's gray matter are noticeable using a brain scanner and observed for more than two years.