Mom brain is not what you think it is. The fog, the forgetting, the sense that your head is no longer cooperating: that is not evidence of decline. It is the sound of a brain in the middle of one of the biggest reorganisations of your life.

Research shows that the female brain changes during pregnancy and the first year after birth on a scale that scientists have only begun to understand in the last decade. The changes are so consistent and so substantial that Hoekzema et al. (2017) were able to identify every mother in their study using only a brain scan, without any other information, with 100% accuracy (Nature Neuroscience, 2017).

You are not becoming less. You're growing.

Before we talk about mom brain: a word you need

You cannot fully understand mom brain without understanding matrescence.

Matrescence is the developmental process of becoming a mother: biological, psychological, social, and existential at once. The term was coined by anthropologist Dana Raphael in the 1970s and brought into contemporary research by psychologist Aurélie Athan. It is the adult equivalent of adolescence: not something that happens to you and that you should leave behind as quickly as possible, but a genuine developmental process with its own function and its own sequence.

Mom brain is not a standalone phenomenon. It is a very real, very significant part of matrescence. We just understand it wrong, in the same way we understand matrescence itself wrong.

The overwhelm, the loss of yourself, the feeling that your head is not working: those things do not mean something is wrong with you. They are the markers of a significant developmental leap. A teenager who no longer recognises herself is not broken. She is growing. That is precisely what is happening to you.

What is actually happening in your brain

In 2017, Elseline Hoekzema and her team published one of the most-cited studies on the maternal brain (Nature Neuroscience). What they found: pregnancy produces substantial, long-lasting changes in brain structure, specifically in areas for social cognition, reading others, and emotional processing. The changes were so consistent that researchers could correctly identify all women in the study as mothers without any other information. The changes remained demonstrably present for a minimum of two years after birth.

This is not damage. The most widely held interpretation: the brain is pruning for efficiency. It is sharpening precisely the circuits you need to read your child, to read them before they have said anything, to read them before they know they need something.

In 2026, Amsterdam UMC published follow-up research (Straathof et al., Nature Communications, 2026) with women experiencing both a first and a second pregnancy. The finding: your brain changes again during a second pregnancy, but differently than the first time. In a first pregnancy, the largest changes are in social cognition and bonding. In a second, they shift to networks for picking up signals from the environment and consciously directing attention: precisely what you need when you have to read multiple children at once.

The researchers put it this way: every pregnancy leaves a unique trace in the female brain.

The only period in adult life with this capacity for growth

This is where it becomes remarkable.

Matrescence is the only period in adult life when your brain can change as rapidly as it did during adolescence. Normally, that growth capacity, that neuroplasticity, is greatest in babies and teenagers. During matrescence, that same period of rapid growth returns.

This was established by Ruth Feldman (Trends in Neurosciences, 2015), one of the most influential researchers on the parental brain and attachment. Her research shows that the degree of brain change is directly related to the amount of active caregiving: the more time you spend in the direct care of your child, the more that brain change actually occurs. And crucially: this applies to fathers and other primary caregivers too.

What does this mean? In this phase, you can release patterns you have been carrying for years, faster than was ever possible at any earlier point in your life. That is not self-help language. That is what neuroscience shows.

But, and this is crucial: it is an opportunity, not a guarantee. If you are completely overwhelmed during that period, have too little support, or are in an environment that expects you to return to who you were before as quickly as possible, that opportunity passes. Not because you have fallen short. But because the system gave you no space.

Most mothers are in exactly that situation.

The paradox: forgetting everything and knowing everything

But I really do forget things. The shopping list, the GP's name, where I put my keys.

That feeling is real. There are indeed studies that find small cognitive deficits, particularly in the third trimester of pregnancy (Davies et al., Medical Journal of Australia, 2018). The effects are small, temporary, and fall within normal cognitive functioning.

What stands out more clearly in the research: the gap between how mothers think they are performing and how they are actually doing. Mothers rate themselves as far more forgetful than they actually are. And research even shows that mothers score better than women without children on emotional regulation, mental flexibility, and social cognition.

You forget the shopping list. You do not forget when your child last ate.

Three explanations for this.

First: your brain is choosing. Everything related to your child's wellbeing, you remember with precise accuracy. The rest you unconsciously release. That is not memory loss. That is a shift in what matters.

Second: the stakes are higher. If you do the laundry wrong, your child might have nothing to wear to school tomorrow. The threshold for "I cannot afford to forget this" has grown. And the higher that threshold, the more you feel like you are failing, even when you are doing fine.

Third: mental load. You are tracking more than ever before. A fuller head feels like a less sharp head. But those are not the same thing.

Behind all three is one common denominator: a system that expects mothers to go through an enormous neurological change and simultaneously to keep performing perfectly. At work, at home, as a partner, as a person. Without rest. Without recognition. Without space.

The forgetting is not the problem. The structure around it is the problem.

And with a second child?

Many mothers say that with a second child it has not become easier, but heavier.

That is accurate, and it has a reason.

With a first child, you still get some space to adjust. With a second, everyone expects you to already know what you are doing. The gentle start is gone, while your brain is again going through a significant phase of change. Nobody tells you that every pregnancy is a new matrescence, with its own character, not a repeat of the first.

Straathof et al. (2026) confirm this: the brain changes during a second pregnancy are different from those in a first. Your brain is adapting to the new situation. That is always messy. It is not decline. It is the next round of the same process.

Three things that genuinely help.

Know that this is a second matrescence, a new transformation, not a repetition.

Recognise the chaos as a sign that your brain is working, not as a sign of deterioration.

And release the expectation that it should be easier. It is not easier. It is different.

Mom brain as leadership development

Here is something most women do not know, and that employers do not know at all.

The skills you are developing right now: empathy, rapid context-switching, not needing all the information before moving forward anyway, holding multiple things in the air simultaneously, making decisions under pressure. These are exactly the skills for which organisations set up enormous leadership programmes.

Research from Rutgers University, published in MIT Sloan Management Review (Duarte, Mangino and Kaplowitz, 2026), compared the skills caregivers develop with what employers say they most urgently need. The overlap: 76.5% of all work-relevant skills. And for the three most in-demand skills across all professions: 100%.

Not nearly. One hundred percent.

Matrescence is leadership development. Nobody just calls it that.

What if we used different language?

Stop saying you have mom brain.

Not because the feeling isn't real. It is. But because the words we use determine how we see our own experience. If we keep describing the fog in our heads as evidence that we are becoming less, we miss what is actually happening.

You are not getting dumber. You are not getting more forgetful. Your brain is growing.

What if you said: my brain is growing?

One note. If the brain fog genuinely persists, and feels different from ordinary tiredness, have it checked. Postpartum thyroid problems occur in 5-10% of mothers (StatPearls/NIH, Postpartum Thyroiditis) and are far too rarely tested. Iron deficiency also plays a role more often than people assume. Ask your GP explicitly for blood tests.

When you understand what is happening in your brain, when you have the map, you look at yourself very differently. That is also the foundation of everything we do at Matermorphosis, and of Mother on MY Terms in particular.

About Babette Lockefeer

Babette Lockefeer is the founder of Matermorphosis and an expert at the intersection of leadership and matrescence. She previously worked as a consultant at McKinsey and as the founder of TheoryY. The Dutch version of this article was published in WIJ Ouders Magazine (June 2026).

Frequently asked questions about mom brain

What is mom brain exactly? Mom brain refers to the experience of forgetfulness, mental fog, and reduced sharpness that many mothers describe during pregnancy and the first year after birth. But research shows the reality is more complex: the maternal brain undergoes a profound neurological reorganisation, in which areas for social cognition, emotional processing, and reading others are strengthened. In most cases, the fog is not decline but the sound of a brain in the middle of significant change.

When does mom brain go away? The small cognitive deficits that can occur during pregnancy are temporary and resolve after birth. The brain changes themselves, the reorganisation in social cognition and emotional processing, are longer-lasting: Hoekzema et al. (2017, Nature Neuroscience) found the changes were demonstrably present for a minimum of two years after birth. That is not a problem; it is the result of the transformation. The fog that comes from surviving and being overloaded, the full head that feels like an empty head, does go away, but it needs time and space.

Does mom brain actually exist, or is it a myth? Both. The experience is real and has a biological basis. But the idea that mothers become less intelligent, less capable, less sharp professionally: that is not what the research shows. On the contrary, mothers score better than non-mothers on emotional regulation, mental flexibility, and social cognition in multiple studies. The stereotype of the forgetful mother only emerged in the 1960s, precisely when women began entering the workforce en masse. Sociologist Madeleine Pownall notes this is not coincidental: it can function as a frame that makes women appear smaller than they are.

How can I reduce mom brain? Start by changing the language: you don't have a "problem" with mom brain, your brain is growing. Then locate the cause correctly. A full head is rarely just a brain issue. How much are you carrying alone? What does the system around you demand of you? The cause is often an unequal distribution at home or a work culture that gives no space for what you are going through. And: request blood tests if symptoms persist. Thyroid problems (5-10% after birth) and iron deficiency are regularly missed.

Does a second pregnancy also affect your brain? Yes, and differently than you might expect. Research by Straathof et al. (Nature Communications, 2026, Amsterdam UMC) shows that every pregnancy leaves a unique trace in the female brain. In a second pregnancy, the brain changes shift from social cognition toward networks for picking up environmental signals and consciously directing attention. Your brain is adapting to the new situation: multiple children, rapid switching, being in two places at once. It is not harder because you are doing it wrong. It is different because it is a different transformation.

Sources

• Hoekzema et al. (2017). Pregnancy leads to long-lasting changes in human brain structure. Nature Neuroscience, 20(2), 287-296.

• Feldman, R. (2015). Sensitive periods in human social development. Trends in Neurosciences, 38(6), 379-392.

• Straathof et al. (2026). Neural changes during a second pregnancy differ from first-time mothers. Nature Communications. Amsterdam UMC.

• Davies, S.J. et al. (2018). Cognitive impairment during pregnancy. Medical Journal of Australia.

• Duarte, Mangino & Kaplowitz (2026). Why businesses should value caregivers now. MIT Sloan Management Review.

• StatPearls/NIH. Postpartum Thyroiditis. National Library of Medicine.