How Pregnancy Changes Your Brain – The Science Behind “Mummy Brain”

Published: December 11, 2024

You’ve probably heard the phrase “mummy brain” thrown around, often with a laugh or an eye roll. It’s usually used to describe those moments of forgetfulness or distraction that seem to pop up during pregnancy and the postnatal period. But what if I told you there’s fascinating science behind this?

It turns out pregnancy literally reshapes your brain in ways that help you bond with your baby and rise to the challenges of parenting. These changes aren’t random—they’re nature’s way of equipping you for one of the most important roles of your life.

 

The Science Behind Pregnancy and Brain Changes

Pregnancy isn’t just about growing a baby—it’s about growing your brain’s ability to care for and connect with that baby.

Pregnancy is a masterclass in biological transformation, and the brain takes centre stage.

Using advanced imaging, researchers have unveiled how pregnancy alters neural pathways to enhance caregiving and bonding.

Key Research Findings

Hoekzema et al. (2017) conducted groundbreaking studies revealing significant structural changes in the maternal brain during pregnancy. These changes primarily occur in regions responsible for empathy, emotion processing, and understanding others’ needs—skills vital for parenting.

Pregnancy and parenthood rewire the brain, deepening empathy and attunement, so a parent can intuitively read their baby’s cues and meet their needs with love, calmness, and connection.

This is the biological norm—a beautifully designed process to provide the nurturing start that builds an emotionally healthy and resilient human being.

Benefit of skin to skin
 

Structural Changes in the Brain 

Gray Matter Volume Decrease

This sounds alarming, but it’s actually a good thing! These reductions occur in regions that help you understand what others are thinking and feeling. The changes make your brain more efficient, like decluttering a messy wardrobe to only keep what you’ll actually wear.

White Matter Volume Increases

While gray matter naturally reduces in specific areas, your brain simultaneously boosts white matter density in regions crucial for emotional regulation, caregiving, and social cognition. This change helps improve the brain’s connectivity and communication, preparing you to respond quickly and effectively to your baby’s needs.

Think of it like this: gray matter is the brain’s processor, and white matter is the high-speed network connecting everything together. By strengthening those “wires,” pregnancy enhances your brain’s efficiency, creating the perfect setup for navigating the journey of parenting with confidence and care.

The Amygdala: Your Emotional Superpower

The amygdala becomes hyperactive during pregnancy and postpartum, making you acutely attuned to your baby’s needs. While this heightened sensitivity ensures your baby’s safety, it can also make you more vulnerable to anxiety.

Think of the amygdala as your brain’s emotional smoke detector. It’s always on alert, scanning for anything that might require your attention—whether that’s your baby’s cry, a loving smile, or even a potential threat. After birth, the amygdala becomes extra sensitive, helping you notice your baby’s needs more quickly and respond with care.

Imagine this: You’re in a room with a smoke detector that’s suddenly tuned to be more sensitive—not just to fire but to any changes, like a candle burning or boiling water. It ensures you don’t miss anything important, especially when it comes to keeping your baby safe.

This hyper-responsive amygdala helps you tune into your baby’s cues—like cries or facial expressions—but it’s a double-edged sword. While it sharpens your caregiving instincts, it can also leave you more vulnerable to anxiety or mood swings, especially without proper support.

 

 

 

 

 

 

 

 

Simple Way to Support Yourself:

To avoid slipping into hypervigilance, anxiety, or mood swings, take time for yourself. Practicing mindfulness, taking deep breaths when you feel overwhelmed, or even stepping outside for a short walk can help calm your nervous system. Remember, responding sensitively doesn’t mean you need to be “on” every second—it’s okay to take breaks or ask for help.

The Ventral Striatum: Parenting Reward Centre

This part of the brain ensures that parenting feels rewarding, even in the face of sleepless nights.

The ventral striatum is your brain’s “warm glow switch.” It lights up when you do something rewarding—like seeing your baby smile, cuddling them, or soothing their cries. This makes caregiving feel good, even during the tough moments.

This isn’t just about feeling good—it’s about motivation. When your ventral striatum activates, it reinforces caregiving behaviours, encouraging you to keep soothing, bonding, and nurturing your baby, even when you’re exhausted. Over time, these moments build a strong foundation for connection and secure attachment.

 

Parenting in Practice:

Don’t let anyone tell you that you’re “spoiling” your baby by responding to their cries or holding them often. Research shows that meeting your baby’s needs helps build a secure attachment, which lays the foundation for healthy development, but it will also activate the ventral system, giving you the reward you deserve and making this period in your life far more enjoyable. Trust your instincts—your brain is beautifully wired to care for your baby

What Causes Forgetfulness in “Mummy Brain”?

If your brain is doing all this amazing work, why do you feel forgetful or distracted? This is where Glynn (2010) comes in. “Mummy brain” isn’t a sign of cognitive decline—it’s your brain reallocating resources to focus on your baby.

Think of it like closing some apps on your phone to conserve battery for the most important task: keeping your baby alive and thriving. You might forget an email, but you’re laser-focused on picking up on your baby’s tiny cues and creating a secure, loving environment.

 

Adaptations in Non-Birthing Parents

 

Brain Changes for All Caregivers

Parenting-related brain changes aren’t exclusive to biological mothers.

While mums experience the most dramatic changes, caregiving itself can reshape the brain, regardless of biology. Studies show that dads and intended parents who are deeply engaged in caregiving also experience adaptations in brain regions tied to empathy and connection

Hormonal Shifts

Caregiving parents, even non-biological ones, can experience rises in oxytocin, enhancing attachment and caregiving behaviours.

Neuroplasticity

Parenting activates your brain’s ability to rewire itself. Engaging in caregiving activities like cuddling, soothing, and feeding strengthens these connections, showing that parenting isn’t just biological—it’s a learned skill.

Parenting in Practice:

If you’re a non-birthing or intended parent, focus on consistent caregiving activities like cuddling, soothing, and talking to your baby. These moments activate the same bonding hormones and brain pathways that build strong connections, regardless of biology.

The Role of  Hormones

Oxytocin: The Love Hormone

Oxytocin is the ultimate “parenting hormone.” It enhances the activity of your brain’s reward system, making caregiving feel emotionally fulfilling, even during those early, sleepless months. It also helps you handle stress, acting as a buffer when challenges arise.

Interestingly, while oxytocin peaks for mothers and their babies often occur during cuddling, fathers and their babies experience their strongest oxytocin surges through playful interactions with each other. This difference highlights how nature has uniquely designed bonding experiences to suit each caregiver’s role, ensuring babies receive the rich variety of connections they need to thrive.

Here is what oxytocin does:

Strengthens Emotional Bonds

Oxytocin surges during labour, birth, and breastfeeding, fostering a deep emotional connection between parent and baby. These oxytocin bursts help the brain associate the baby with feelings of love, safety, and reward, making caregiving feel fulfilling and instinctive.

Enhances Social and Emotional Regulation

Oxytocin affects brain areas like the amygdala and prefrontal cortex, which are involved in processing emotions and social cues. This helps parents become more attuned to their baby’s needs, interpreting cries, facial expressions, and body language with heightened sensitivity.

Reduces Stress and Anxiety

Oxytocin has calming effects, lowering cortisol (the stress hormone) levels. This helps parents manage the demands of caring for a newborn by fostering patience and resilience, even during sleepless nights.

Rewires Neural Pathways

Oxytocin promotes neuroplasticity—the brain’s ability to rewire itself. During the transition to parenthood, it helps shape new neural connections that prioritise caregiving behaviours, such as soothing, feeding, and protecting the baby.

Boosts Caregiving Motivation

By activating the brain’s reward system, oxytocin makes parenting behaviours feel pleasurable. This is why moments like snuggling, breastfeeding, and skin-to-skin contact feel so rewarding—they’re fueled by oxytocin, reinforcing the bond between parent and baby.

In short, oxytocin acts as a powerful “neural sculptor,” helping parents adapt to the demands of caregiving while creating an unbreakable bond with their baby. It’s the ultimate hormone for building secure attachment and ensuring babies thrive in their earliest days of life.

How to Supercharge Oxytocin:

Start building your bond with your baby during pregnancy. Simple practices like talking to your baby, singing to them, or even gently placing your hands on your belly while imagining your future together can help foster this connection. These small moments can release oxytocin, which strengthens the growing bond and boosts your brain changes

After birth, continue to nurture these oxytocin peaks through moments of closeness with your baby, like cuddling and soothing. For dads and non-birthing parents, playful interactions can also supercharge oxytocin, offering another powerful way to bond. Each unique interaction—whether cuddles or play—builds a strong foundation for connection and helps your baby thrive.

When Stress Complicates the Parental Brain: The Vulnerability of Neuroplasticity

With neuroplasticity—the brain’s ability to adapt and reorganise—comes vulnerability. While the parental brain is beautifully primed to change and grow in response to caregiving, these changes are deeply influenced by the environment. Stress can interfere with these positive adaptations. Stress keeps the brain in “survival mode,” prioritising immediate threats over connection, making it harder to respond sensitively to a baby’s cues.

Modern societies place extraordinary pressure on new mothers. While humans evolved as an allo-parenting species—meaning caregiving was traditionally shared among extended family, friends, and the wider community—many new mums today are expected to care for their baby in isolation. Without the “village” that historically provided practical and emotional support, stress is a reality for most modern mothers, who are juggling their baby’s needs alongside their own.

For parents under extreme stress, even a baby’s cry—a natural cue for connection—can feel overwhelming, like one more demand on an already overloaded system.

The good news?

Neuroplasticity works both ways. With support and stress-reduction tools, the parental brain can adapt in ways that foster connection and attunement. Seeking support, whether from family, friends, community programmes, or professionals, can help reduce the stressors that interfere with the caregiving brain.

 

Understanding the Polyvagal Theory

The polyvagal system, which regulates your stress responses, plays a critical role here. When parents feel safe and calm, their ventral vagal system (the part responsible for connection and social engagement) is active, making it easier to respond lovingly to their baby. But when stress is high, the fight-or-flight system takes over, and babies’ cries can feel more like a threat than a call for connection.

More good news? The polyvagal system is trainable. Simple techniques like deep breathing, grounding exercises, and mindfulness can help calm your nervous system, returning you to a state where connection feels natural. These tools are small but powerful ways to support both your well-being and your relationship with your baby.

Train your polyvagal system by practicing stress-reduction techniques like slow, deep breaths, grounding exercises, or even humming to yourself. These small actions can help calm your nervous system and bring you back to a place where responding to your baby feels natural and joyful.

Practical Strategy:

If stress feels overwhelming, reach out for support or find small moments of calm through grounding techniques like focusing on your breath or practising mindfulness. These can help reset your brain’s caregiving circuits

The Big Picture: Your Brain is Built for Parenting

Pregnancy and the postpartum period transform your brain in ways that prioritise bonding, caregiving, and adapting to your baby’s needs. These changes aren’t random—they’re nature’s way of setting you up for success in one of life’s most challenging and rewarding roles.

Understanding the science behind these brain changes can help you give yourself grace during this transformative time. You’re not “losing” your mind—you’re upgrading it for the beautiful (and demanding) journey of parenting.

Next time someone jokes about “mummy brain,” you can smile and say, “Actually, my brain just got a serious upgrade—and it’s doing an incredible job.”

Remember, parenting was never meant to be done alone. Surrounding yourself with support and practicing simple stress-reduction strategies can help you—and your beautifully adaptable brain—flourish during this incredible chapter.

Would you like to know more about how your brain adapts during the parenting journey? I offer practical tools and gentle guidance to support your parental brain during this transformative time, helping you navigate the challenges and embrace the joys of early parenthood. Let’s chat—I’m here to support you every step of the way. ????

FAQs

What is “mummy brain,” and is it real?

“Mummy brain” is a term used to describe cognitive changes during pregnancy and postpartum. It’s real, but it doesn’t indicate cognitive decline. Instead, it reflects a natural reallocation of brain resources to focus on bonding and caregiving.

How does pregnancy affect the brain’s structure?

Research shows that pregnancy causes a reduction in gray matter volume in areas associated with social cognition and emotional regulation. This change makes the brain more efficient at understanding and responding to a baby’s needs. Think of it like decluttering a messy wardrobe to only keep what you’ll actually wear.

Can dads, non-birthing and intended parents experience brain changes?

Yes, caregiving can reshape the brain for all deeply involved parents. Hormonal changes like increased oxytocin and neuroplasticity adaptations help non-birthing and intended parents bond with their baby and respond to their needs.

Why do mothers feel forgetful during pregnancy?

The perceived forgetfulness, often called “mummy brain,” occurs because the brain prioritises parenting tasks over less critical functions. It’s like closing background apps on your phone to save battery for essential tasks.

How long do these brain changes last?

The structural and functional changes in the parental brain often persist for at least two years postpartum, with some lasting even longer. These adaptations ensure long-term caregiving and emotional connection.

What role does oxytocin play in the parental brain?

Oxytocin, known as the “love hormone,” enhances emotional bonding, reduces stress, and activates the brain’s reward system, making caregiving feel fulfilling and natural.

Can stress negatively impact the parental brain?

Yes, chronic stress can interfere with positive brain changes by keeping the brain in survival mode. This can make it harder to connect with and respond sensitively to a baby’s needs. Stress-reduction strategies are essential for new parents.

How can parents manage stress to support their brain changes?

Practicing mindfulness, deep breathing, and grounding exercises can help regulate the stress response. Seeking help from family, friends, or community programs can also reduce the impact of stress on brain adaptations.

How can the polyvagal system improve parenting?

The polyvagal system regulates stress responses. Practices like deep breathing, EFT, mindfulness, and grounding techniques help activate the social engagement system, fostering calmness and enhancing the parent-baby connection.

Contact Pip

 

If you have any questions or would like to attend one of Pip’s workshops then get in touch now.

 

 

REFERENCES

Hoekzema, E., Barba-Müller, E., Pozzobon, C., Picado, M., Lucco, F., García-García, D., & Vilarroya, O. (2017). Pregnancy leads to long-lasting changes in human brain structure. Nature Neuroscience, 20(2), 287–296.https://doi.org/10.1038/nn.4458

Feldman, R., Weller, A., Zagoory-Sharon, O., & Levine, A. (2007). Evidence for a neuroendocrinological foundation of human affiliation: plasma oxytocin levels across pregnancy and the postpartum period predict mother-infant bonding. Psychological Science, 18(11), 965-970. https://doi.org/10.1111/j.1467-9280.2007.02010.x

Kim, P., Leckman, J. F., Mayes, L. C., Newman, M. A., Feldman, R., & Swain, J. E. (2010). Perceived quality of maternal care in childhood and structure and function of mothers’ brain regions associated with empathy and stress. Journal of the American Academy of Child & Adolescent Psychiatry, 49(11), 1144-1154. https://doi.org/10.1016/j.jaac.2010.08.019

Glynn, L. M. (2010). Giving birth to a new brain: Hormone exposures of pregnancy influence human memory. Psychoneuroendocrinology, 35(8), 1148-1155. https://doi.org/10.1016/j.psyneuen.2010.01.015

Abraham, E., Hendler, T., Shapira-Lichter, I., Kanat-Maymon, Y., Zagoory-Sharon, O., & Feldman, R. (2014). Father’s brain is sensitive to childcare experiences. Proceedings of the National Academy of Sciences, 111(27), 9792–9797. https://doi.org/10.1073/pnas.1402569111

Swain, J. E., Kim, P., & Ho, S. S. (2014). Neuroendocrinology of parental response to baby-cry. Journal of Neuroendocrinology, 26(10), 796–801. https://doi.org/10.1111/jne.12176

Eid, R. S., Gobinath, A. R., & Galea, L. A. M. (2019). Neuroplasticity and the maternal brain: Ongoing adaptations to motherhood. Frontiers in Neuroendocrinology, 53, 100740. https://doi.org/10.1016/j.yfrne.2018.12.004

 

Aspen Institute Ascend. (2021). New research shows parenting brain changes in all caregivers. https://ascend.aspeninstitute.org/new-research-shows-parenting-brain-changes-in-all-caregivers/

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