So-called “baby brain” refers to increased forgetfulness, inattention, and mental “fogginess” reported by four out of five pregnant women. These changes in brain function during pregnancy have long been recognised in midwifery folklore, but our new study has confirmed “baby brain” is a very real phenomenon, and also affects several cognitive areas.
We combined data from 20 studies reporting the relationship between pregnancy and brain changes. We then pooled these differences together to assess the cognitive functioning of 709 pregnant women and 521 non-pregnant women.
Our study, published in the Medical Journal of Australia, is the first to explore how pregnancy may affect other cognitive areas beyond memory and to look specifically at how these changes might vary according to pregnancy trimesters.
What we found
Our results showed that when pregnant women are compared to non-pregnant women, they perform much worse on tasks measuring memory and executive functioning (which includes attention, inhibition, decision-making and planning), and this difference is most pronounced during the third trimester. Women were tested with tasks such as the digit span test, which involves remembering digits in a line.
We also found when the same women were tested at multiple points during their pregnancies, the decline appeared to start during the first trimester, then stabilise from the middle to the end of the pregnancy.
But it’s important to note that while we found differences, the pregnant women were still broadly performing in the normal range, albeit at the lower end, particularly for memory tasks. So while some pregnant women may notice they don’t feel as “sharp” as usual, these effects are realistically not likely to have any dramatic impact on everyday life.
Instead, some women will simply find it seems to take more mental effort to do tasks that were previously routine. These changes might be noticeable to people very close to them such as family or friends, but this is highly dependent on each woman’s personal experience of pregnancy.