Suffering from “mom brain”? When a mom forgets anything, we usually attribute it to mom brain. But, could it just be sleep deprivation, an overworked mind or something more serious? Or has a real shift occurred in the brain? Also, how long will this last, or is this change permanent?
It turns out that real changes occur in women’s brains during pregnancy and these changes are not just perceived or imagined. This is what we know so far.
Research shows that during pregnancy, mothers’ brains lose volume and change structure. When they scanned the same mothers again, the scans showed that their brain volume grew in the first three to four months after delivery. All this activity occurs mainly in the regions involving the “maternal instinct,” decision making, learning, and regulating thoughts, actions and emotions. These changes are attributed to the brain pruning neural connections to free up and reallocate its resources. Scientists hypothesize that these resources are reassigned to prioritize bonding with and caring for the baby.
In real-time scans, those same regions of mothers’ brains lit up when shown pictures of their babies (versus when shown images of other babies). Fathers who are primary caretakers also register a lot of activity in their amygdala, which manages fear, anger, memory and decision-making. However, they did not notice any loss of brain volume in dads.
“There is no convincing scientific evidence that pregnancy causes an overall decline in cognitive performance or memory” (3). When researchers test new mothers, the results reveal that the ability to recall words (or say, a TV character’s name) appears to be compromised. But, learning, reasoning and comprehension seem unaffected. In rodent studies, mothers are better at mazes than non-mothers once her pups became independent. Is this because these mothers have benefitted from resource allocation?
Is mom brain just a bunch of hormonal changes?
Hormones are another factor to consider as well. During pregnancy, steroid hormone levels (like progesterone) rise. Some reach “200 to 300 times normal levels for months at a time” (4). Some of the receptors in the brain are sensitive to steroid hormones and are believed to switch on “maternal behavior.” After delivery, these fluctuations can, sometimes, cause compulsive disorders and postpartum depression. These two disorders are concrete examples of alterations in the brain caused by pregnancy. What’s interesting is that oxytocin-the hormone present during labor, pregnancy & nursing-helps mothers forget the bad parts of childbirth (2). But, it also helps maintain the good feelings from new motherhood. Some believe it is an evolutionary function to keep the species alive. Logically, these shifts in the brain and behavior also seem consistent with the typical “symptoms” of mom brain.
Is this change in the brain permanent?
This neuroplasticity or reorganizing of connections takes effect for at least two years. The hippocampus-the area that consolidates short- and long-term memory-regains volume after two years. This growth may be due to all the learning involved in new motherhood. Incidentally, the brain also loses volume during adolescence, which is another hormonally charged period in life when the brain also undergoes pruning and reorganizing.
This area of study is young so little is known about what happens after the child turns two or after multiple births. Some think that because the changes are still in effect after two years, these changes are permanent. After giving birth, the hormone levels during a mother’s menstrual cycles are lower than before giving birth. Some say it prevents certain types of cancers, but note that this switch is permanent. So, it’s possible that the changes in the brain are also permanent.
Even more permanent changes in a mother’s brain
As the fetus develops in the mother, it sloughs off cells. They travel through the mother’s bloodstream and can end up in the brain, bones or any other part of their bodies. In mice, they found that the cells that end up in the mother’s brain often turn into neurons and become part of her brain. When examined after death, mothers with more of their children’s cells in their brain had fewer signs of Alzheimer’s disease. On the other hand, some researchers believe these cells are just clutter and don’t have any significance. Not enough research has been done in this area of study, but it’s interesting to see what real and permanent shifts are observed in a mother’s brain.
So, the next time mom brain hits, cut yourself some slack. Genuine changes are occurring in a mom’s brain. You aren’t losing your mind, but one expert called it a “maturation or specialization” of the mind that not everyone gets to experience (1). Don’t stress about it and let the resource reallocation take place so you can excel at the maze of motherhood.
Read more posts about Mind where we discuss strategies for maintaining mental balance.
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Publications:
(1) Belluck, Pam. “Pregnancy Changes the Brain in Ways That May Help Mothering.” The New York Times, The New York Times, 19 Dec. 2016, www.nytimes.com/2016/12/19/health/pregnancy-brain-change.html?module=inline#.
(2) Heinrichs, M., Meinlschmidt, G., Wippich, W., Ehlert, U., & Hellhammer, D. H. (2004). Selective amnesic effects of oxytocin on human memory. Physiology & Behavior, 83(1), 31–38. https://doi.org/10.1016/j.physbeh.2004.07.020
(3) Sacks, Alexandra. “Reframing ‘Mommy Brain’.” The New York Times, The New York Times, 11 May 2018, www.nytimes.com/2018/05/11/well/family/reframing-mommy-brain.html.
(4) Vlasits, Anna. “Moms: Your Kids Hijacked Your Brain for Life.” Wired, Conde Nast, 14 May 2017, www.wired.com/2017/05/moms-kids-hijacked-brain-life/.
(4) Ziegler, Sheryl. Mommy Burnout: How to Reclaim Your Life and Raise Healthier Children in the Process. Dey Street Books, 2018.
