“Baby brain” — which has been reported by four out of five pregnant women — includes increased forgetfulness, trouble concentrating and mental fogginess. But until now, the existence of this phenomenon has not been fully supported by science, with multiple studies reaching inconclusive results.

But researchers from Deakin University conducted a meta-analysis on 20 studies that reported on the relationship between pregnancy and brain changes to confirm that “baby brain” is indeed real, and affects several cognitive areas.

Data from the 20 studies included a total of 709 pregnant women and 521 non-pregnant women as a control group. The studies all also included at least one standard objective measure of cognitive function.

The Deakin University team found that pregnant women did perform much worse on tasks measuring memory and executive functioning compared to non-pregnant women. One of the memory tasks included a digit span test, which requires remembering digits in a line. Executive functioning refers to attention, inhibition, decision-making and planning.

The effects of “baby brain” were most pronounced during the third trimester, the analysis found.

The results “are consistent with recent findings of long term reductions in brain grey matter volume during pregnancy,” the study authors wrote.

The analysis, published in the Medical Journal of Australia, is the first to explore how pregnancy may affect other cognitive areas beyond memory, and looked specifically at how these changes may vary according to pregnancy trimesters.

The researchers do note that although there were pronounced differences, the decline in the pregnant women’s cognitive and memory function still remained within a functional range. This suggests that while pregnant women may report that they don’t feel as mentally sharp as they usually do, the effects of “baby brain” should not have a dramatic impact on their daily lives.

Determining what exactly causes “baby brain” is something that will require additional research, the study authors reported.