Pregnant and forgetful? You’re not alone

“Baby brain”, the sub-optimal state of memory and planning abilities often reported by women during pregnancy, is real, according to an Australian meta-analysis.

A team led by Sasha Davies from Deakin University in Melbourne, Victoria, sifted through more than 3000 studies into memory and cognition during pregnancy, finally selecting 20 that were large and rigorous enough to use. The studies included a total 709 pregnant and 621 non-pregnant women.

Looking at differences in memory, general cognitive function and executive planning between pregnant and non-pregnant women – and between trimesters in the pregnant cohort – the researchers found results that were statistically significant. 

However, they note that while deficits were quantifiable – particularly in the third trimester – performance remained within normal limits. For this reason, they warn in a paper published in the Medical Journal of Australia (MJA), their findings need to be treated with caution. More longitudinal research, they say, is needed.

Davies and her colleagues found that memory, cognition and executive planning were all significantly lower during pregnancy, especially during the third trimester. Memory decline sets in early, between the first and second trimesters, but then slows or halts completely from mid-pregnancy on.

The researchers write that by third trimester, however, memory performance decline coupled with impacts on cognition lead to an overall change that “is not only statistically, but also clinically significant”.

Because the ability to function in the physical world is only mildly affected, the scientists report, “baby brain” symptoms may only be noticeable to the pregnant woman herself and perhaps those to whom she is closest. Typically, they will manifest as minor memory lapses, such as neglecting to make or attend a medical appointment.

More serious consequences, such as a decline in performance in the workplace, are less likely.

The meta-analysis confounds previous research that found pregnancy only adversely affects working memory and recall. Davies’ team found that these impacts on working memory may be only isolated facets, and that “pregnancy may be associated with declines across broader memory functions”.

Having built a statistical case for baby brain as a significant and complex syndrome, the researchers then note that it remains unclear whether cognitive and memory functions return to previous levels after giving birth. They call for more research to better map brain function before, during and after pregnancy.