Pregnant women often have a feeling of forgetfulness, it is the so-called “mom’s brain”, or “baby’s brain”.

Is it just an expression or is there any scientific truth behind it?

The brain of pregnant women has always been an interested topic for scientists. In 2017 Hoeckzema and collaborators published on Nature the definitive paper about this topic. Researchers applied MRI (computer imaging) to measure the structural changes that occur in the brain of 25 women before they were pregnant and after pregnancy.

Results show a reduction in the gray matter of the brain, specifically in the front and temporal lobe regions, the ones involved in social interactions.

Although the idea of loosing grey matter is not so appealing, apparently it is an evolutionary trait which help mothers to have greater feelings of attachment and fewer negative emotions towards their babies. The smaller the brain gets, the more efficient it becomes. In that way newly mothers’ brain is preparing itself to better interpret baby’s body language, cry types and to identify possible threats.

Researchers analyzed also the brain of 19 fathers. MRI results show that the changes occur only in mothers’ brain.

Scientists reanalyzed the women’s brain after 2 years. 11 of the original 25 women did not have a second child. The changes detected 2 years before, were still there in both women without other children and women who gave birth to other babies.

This study does not support the popular idea that pregnant women and newly mothers forget things more easily. The brain needs to focus more important things that “I have to record this TV show tonight”.

Mother’s brain becomes more efficient and organized to help women taking better care of these little and helpless creatures called newborns.

References:

Brett and Baxendale, “Motherhood and memory: a review”, (2001), https://doi.org/10.1016/S0306-4530(01)00003-8

Buckwalter et al., “Pregnancy and postpartum: changes in cognition and mood”, (2001), https://doi.org/10.1016/S0079-6123(01)33023-6

Hoekzema et al., “Pregnancy leads to long-lasting changes in human brain structure.”, (2017), https://doi.org/10.1038/nn.4458

Oatridge et al., “Change in brain size during and after pregnancy: study in healthy women and women with preeclampsia.”, (2002), http://www.ajnr.org/content/23/1/19.long