If you've ever forgotten an appointment, lost track of a sentence mid-thought, or left the chicken in the freezer the night you meant to defrost it, you've likely felt what's colloquially called "mom brain." The cognitive fogginess of new motherhood is common, real, and rooted in measurable brain changes — yet few women are told why it happens or what actually helps.
Needed asked research neuroscientist Dr. Nicole Avena to explain what the science says.
Key Takeaways
- 80% of new mothers experience working memory difficulties during pregnancy and postpartum — "mom brain" is a documented neurological phenomenon driven by hormonal shifts, sleep disruption, and routine changes, not a personal shortcoming.
- The hippocampus, the brain region responsible for memory and learning, temporarily shrinks during pregnancy and early postpartum — this structural change is a primary contributor to the reduced recall and working memory new mothers notice.
- Estrogen and progesterone rise exponentially in pregnancy and drop sharply after delivery, alongside fluctuations in cortisol, testosterone, and oxytocin — hormonal fluctuations, more than sleep loss alone, are likely the largest driver of mom brain.
- Reduced grey matter in the maternal brain predicts stronger mother-baby attachment after birth — these adaptations, observable up to 2 years postpartum, specialize the brain for parenting rather than simply impairing it.
- Nutrients like carotenoids, phosphatidylserine, ashwagandha, and lion's mane can support cognitive function and a healthy stress response postpartum — pairing targeted nutrition with routine anchors like consistent walks and mealtimes helps support working memory as the brain readjusts.
What is "Mom Brain"?
Suddenly forgetting the appointment you made last week or the chicken you meant to defrost for dinner can be not only frustrating but also exhausting. On top of taking care of a newborn, you may be experiencing “mommy brain”. Reports show that 80% of new moms experience working memory trouble during pregnancy and postpartum.
Working memory allows our brains to absorb information without losing track of what we are already doing. It allows us to process information and use it later. This is what plays a big role in mommy brain- and forgetting to take the chicken out of the freezer for dinner.
You’re probably asking yourself why this happens. And the answer is it is a huge combination of factors that influence our working memory. Below are three factors that affect working memory in new motherhood.
Poor Sleep
Deep, regular sleep is when the brain rests, recovers, and consolidates memory. The two main sleep states — non-rapid eye movement (NREM) and rapid eye movement (REM) — each play distinct roles in sleep-dependent memory processing and consolidation. New mothers who wake multiple times a night to feed a baby rarely reach the recommended amount of deep sleep, and their cognitive sharpness (and stress levels) reflects it.
Routine Disruptions
A predictable daily routine supports higher cognitive capacity. A newborn's feeding schedules, nap windows, and endless to-dos replace that routine almost overnight, making it easier to lose track of appointments and prior commitments.
Hormones
The hormonal shifts of pregnancy and postpartum are likely the single largest component of mom brain — and they deserve a much more in-depth breakdown and attention.
How Do Pregnancy Hormones Change the Brain?
Levels of progesterone and estrogen rise exponentially during pregnancy to support fetal development, then decline rapidly after delivery. Testosterone, cortisol, and oxytocin also fluctuate through this transition. These fluctuating hormone levels affect both brain function and brain structure.
Some of these brain adaptations help mothers attune to their baby's needs and build mother-baby attachment. Others contribute to the fog. The hippocampus — the brain region central to memory and learning — actually shrinks during pregnancy and early postpartum, contributing to reduced recall and working memory.
The body also experiences a sharp change in both cortisol and estrogen after birth. In the research literature, these shifts in serum estrogen and cortisol levels have been linked to verbal recall and processing speed in late pregnancy and the early postpartum period.
Why Mom Brain Is an Adaptation, Not a Deficit
These changes may sound daunting — as if postpartum brain fog and poor memory are a sentence. They're not. The maternal brain is reorganizing, not breaking down.
Studies show that new mothers often have less grey matter in specific brain regions, and this change in grey matter predicted maternal attachment after birth. The adaptations the brain makes in the shift into motherhood allow it to become more specialized — and research links these changes to positive parenting outcomes. These volume and grey matter changes have been observed up to 2 years postpartum, indicating that the timeline of specialization varies from mother to mother. The tradeoff is real, but so is the payoff: a brain increasingly tuned to bond with and respond to your baby.
How Can New Moms Support Cognition?
Mom brain affects most mothers, but you can support your cognitive health through nutrition, targeted supplementation, and lifestyle changes.
Rebuild routine with anchors
Every day looks different with a newborn, but small, repeatable habits support working memory. Anchors like a morning and evening walk, or meals at roughly the same time each day, restore some of the structure the brain relies on. Baby-tracking apps can handle remembering feedings and nap times so your working memory doesn't have to.
Support Your Brain Health with Nutrition
Beyond a quality prenatal, certain nutrients can support cognitive health during the postpartum transition:
- Adaptogens like ashwagandha and lion's mane work with your body to support cognitive health and a healthy stress response.
- Carotenoids help protect the brain from oxidative stress and support overall brain function and health.
- Phospholipids like phosphatidylserine help maintain brain cell integrity and support cognitive function.
Looking for supplements that include these ingredients can help support your brain through the demands of new motherhood.
Protect sleep where you can
Perfect sleep isn't realistic with a newborn, but prioritizing rest when the opportunity exists — including accepting help so you can nap — gives the brain more of the deep sleep it uses to consolidate memory.
Frequently Asked Questions
Is mom brain real?
Yes. Mom brain is a documented neurological phenomenon, not a myth. Research published in JAMA Neurology reports that 80% of new mothers experience working memory difficulties during pregnancy and postpartum, and brain imaging studies show measurable structural changes, including temporary shrinkage of the hippocampus.
What causes mom brain?
Mom brain results from three overlapping factors: dramatic hormonal shifts (estrogen and progesterone rise exponentially in pregnancy and drop sharply after birth), sleep disruption that limits the deep NREM and REM sleep the brain uses to consolidate memory, and the loss of daily routine that normally supports cognitive function. Hormonal fluctuation is likely the largest single driver.
How long does mom brain last?
Brain changes associated with motherhood have been observed for up to 2 years postpartum, though the timeline varies from mother to mother. Many of the cognitive effects ease as hormones stabilize, sleep improves, and routines return.
Does mom brain mean my brain is damaged?
No. The maternal brain is specializing, not deteriorating. Studies show that the reduction in grey matter observed in new mothers predicted stronger maternal attachment after birth — the brain trades some working memory capacity for heightened attunement to your baby.
What nutrients support cognitive function postpartum?
Nutrients studied for cognitive support include adaptogens like ashwagandha and lion's mane (which support cognitive health and a healthy stress response), carotenoids (which help protect the brain from oxidative stress), and phospholipids like phosphatidylserine (which help maintain brain cell integrity and support cognitive function). These can complement — not replace — a quality prenatal, restored routines, and rest.
Can I prevent mom brain entirely?
No — the hormonal and structural brain changes of motherhood are natural and largely unavoidable. But you can support your working memory through routine anchors (consistent walks, regular mealtimes), baby-tracking apps that offload reminders, protected rest, and targeted nutrition.
The Bottom Line
All in all, we can’t prevent every sign and symptom that comes with postpartum - but we can aim to lessen the mental toll it can take on both mom and partner.
Mommy brain is no joke- and can affect anyone at any time during postpartum. I recommend trying Needed’s Cognitive Support to support focus, attention, brain health and memory. All ingredients included are science-backed and provide essential nutrients for mommy brain.
Nutrition is one meaningful lever. Needed's Cognitive Support is formulated with science-backed ingredients — including the nutrients discussed above — to support focus, attention, brain health, and memory during this season.
