What Is Baby Brain: The Science of Forgetfulness

Have you ever walked into a room and completely forgotten why you went in there in the first place? Has there been a word on the tip of your tongue, but you had absolutely no recall?  Or perhaps you've found yourself frantically searching for your phone, only to realize it's been in your hand the entire time?

If you’re nodding along keep reading.  

Picture this, you bring your new baby to meet your extended family. Aunt Gloria gifts you brand-new baby clothes. Unfortunately, you accidentally leave the gift on the roof of your car, only to realize your mistake when you see baby clothes blown away and scattered all over the street. (Tiffany, mom of two)

Or this…

Ah, the joys of baby brain! It is your first solo outing with your two-week-old baby. You did it! You made it out of the house and remembered your wallet, your phone, your keys, the diaper bag, the stroller, the extra stroller-connector-piece, your reusable grocery bags—that you always seem to leave in your car— even better, you buy everything on the grocery list! You head home proud of your success. Hours later, your partner asks why the garage door is opened and the groceries still in the trunk of the car? (Miriam, mom of one)  

Or this…

Your anniversary is coming up and you recently gave birth to your second child. You know you haven’t been your best self lately, so you want to gift something thoughtful to your husband. You have the gift engraved, but instead of his initials, you accidentally put your own. (Jamie, mom of two).

Welcome to the club of "baby brain" sufferers! For many of us, especially new parents, experiencing moments of forgetfulness, absent-mindedness, and general cognitive fuzziness is all too familiar. But did you know there's a scientific explanation behind this phenomenon?

What Exactly Is Baby Brain? 

Also known as "mommy brain" or "pregnancy brain," baby brain refers to the cognitive changes that occur during pregnancy and in the postpartum period. Contrary to popular belief, it's not a figment of our sleep-deprived imaginations, but rather a very real and scientifically recognized phenomenon. While pregnancy and caring for a newborn certainly contribute to difficulty with focus and absent mindedness, it's not solely the result of sleepless nights and endless diaper changes. In fact, research suggests that hormonal changes play a significant role in rewiring the brain during pregnancy, affecting memory, attention, and executive function. In a previous post, Pregnancy Brain: Not What You Think, I shared innovative research of the time. Now there is more research on what happens to the brain during pregnancy, labor and delivery and the postpartum period.

The Science of Forgetfulness

Research found that pregnancy alters the structure of the brain, particularly in regions associated with social cognition, emotional regulation and maternal behavior. Hormonal fluctuations during pregnancy are hypothesized to be responsible for some of the observed brain changes. Gray matter is decreased in the brain during pregnancy, which is linked to increased brain activity around empathy. One study, looked at brain activity when new mothers were shown photographs of their babies crying; those with less gray matter experienced more brain activity in regions associated with empathy and understanding. Changes in gray matter during pregnancy and childbirth play a crucial role in facilitating maternal bonding and adapting to the demands of parenthood.

The brain is fine-tuning itself to optimally respond to the needs of the newborn. While these brain changes are typically reversible and the brain largely returns to its pre-pregnancy state postpartum, the speed and extent of recovery may vary depending on the type of delivery. Women who had a vaginal birth or initiated labor, but ultimately had an emergency cesarian section took longer to recover from the gray matter declines compared to women who had a scheduled c-section. One potential explanation for the prolonged recovery from gray matter involves the physiological stress response associated with these different birthing experiences. Vaginal birth and labor initiation typically entail more intense physical exertion and hormonal fluctuations compared to scheduled cesarean sections, which might impact the brain's adaptation processes. Additionally, the emotional and psychological stress of unexpected medical interventions during labor, such as with an emergency c-section, could contribute to prolonged recovery periods of gray matter. Further research into the interplay between physiological, hormonal, and psychological factors during childbirth may provide insights into the brains ability to adapt and how this contributes to mother-child attachment and bonding.

The science behind baby brain raises several questions, including whether non-birthing or adoptive parents undergo similar brain changes. Or if there are other adaptive changes that facilitate parent-child bonding. This underscores the need for more research in the emerging field of maternal neuroscience.

So, the next time you find yourself forgetting why you walked into a room, or looking down and realizing that you have two different sneakers on your feet; know that you are not alone. Find comfort in the fact that your forgetfulness has a reason and a purpose.

Perhaps one day, you'll look back on these absent-minded, baby-brained moments with fondness, reminiscing about the chaotic yet magical journey of parenthood.

Now, if you'll excuse me, I think I left my keys in the fridge...

Check out this week’s Therapist in Your EAR episode to learn more about baby brain and forgetfulness.

Acknowledgements:

Thank you to my friends who let me share their baby brain stories for this post. The most common response to, tell me a time you experienced baby brain was, “I don’t remember, does that count?” Yes, it certainly does!

References:

1. Anania, C. (2024). Reshaping the brain during pregnancy. Nat Genet 56, 8 https://doi.org/10.1038/s41588-023-01630-5

2. Chechko N, Dukart J, Tchaikovski S, Enzensberger C, Neuner I, Stickel S. (2022). The expectant brain-pregnancy leads to changes in brain morphology in the early postpartum period. Cereb Cortex. 2022 Sep 4;32(18):4025-4038. doi: 10.1093/cercor/bhab463. PMID: 34942007; PMCID: PMC9476604.

3. Hoekzema, E., van Steenbergen, H., Straathof, M. et al. (2022) Mapping the effects of pregnancy on resting state brain activity, white matter microstructure, neural metabolite concentrations and grey matter architecture. Nat Commun 13, 6931 https://doi.org/10.1038/s41467-022-33884-8

4. Jimenez, G (2024). Pregnancy and childbirth reshape the brain in sometimes lasting ways. Scientific American. https://www.scientificamerican.com/article/pregnancy-and-childbirth-reshape-the-brain-in-profound-sometimes-lasting/#:~:text=Much%20of%20the%20scientific%20literature,least%20six%20years%20after%20pregnancy.

5. Paternina-Die, M., Martínez-García, M., Martín de Blas, D. et al. (2024). Women’s neuroplasticity during gestation, childbirth and postpartum. Nat Neurosci 27, 319–327 https://doi.org/10.1038/s41593-023-01513-2

6. Woodside, B (2006). Morphological plasticity in the maternal brain: Comment on Kinsley et al.; motherhood and the hormones of pregnancy modify concentrations of hippocampal neuronal dendritic spines, Hormones and Behavior, Volume 49, Issue 2,2006, Pages 129-130,ISSN 0018-506X, https://doi.org/10.1016/j.yhbeh.2005.09.001.