Pregnancy Brain Is Real: What New Research Reveals About “Momnesia”
By Dr. Savannah Patel | Reproductive Psychiatry at Patel Mind and Body
Have you ever walked into a room and completely forgotten why you were there? Misplaced your phone for the third time that day? Or read the same paragraph over and over and realized you still have no idea what it said?
If you’re pregnant, you may have experienced what people often call “pregnancy brain,” “baby brain,” or “momnesia.”
For years, women have described feeling more forgetful, distracted, or mentally foggy during pregnancy. These experiences are often brushed off as just another normal part of pregnancy, but new research is giving us a better idea of what may actually be happening in the brain.
A recent study published in Science Bulletin identified a specific brain circuit that may help explain why memory can feel different during pregnancy.
And to me, the bigger takeaway is this: pregnancy changes the brain in very real ways. It isn’t just a physical transition.
So, What Exactly Is Momnesia?
“Momnesia” is a casual term for the changes in memory, attention, and mental sharpness that some women notice during pregnancy and postpartum.
You may find yourself forgetting names, losing track of what you were doing, struggling to stay organized, or simply feeling a little less mentally quick than usual.
For women who are used to juggling work, home, schedules, appointments, and everyone else’s needs, this can be super frustrating.
The tricky part is that research has not always shown a clear, consistent pattern. Not every woman experiences pregnancy brain, and the severity can vary quite a bit.
Until recently, we also haven’t had a very good explanation for why it might happen.
What Did the New Research Find?
Researchers from Baylor College of Medicine and other institutions looked at how the very high estrogen levels of pregnancy may affect memory.
Estrogen is important for many aspects of brain function, but pregnancy creates a very different hormonal environment than we experience during a normal menstrual cycle.
In experiments involving mice, the researchers found that pregnancy-level estrogen temporarily impaired certain types of memory.
They were also able to identify a specific pathway between two areas of the brain:
The hypothalamus, which plays a major role in hormonal regulation
The hippocampus, which is heavily involved in learning and memory
When estrogen levels were high, certain neurons in the hypothalamus became more active. Those neurons then sent inhibitory signals to the hippocampus.
In other words, the researchers found a pathway by which high estrogen could essentially “turn down” part of the brain’s memory system.
When they blocked that pathway in the mice, the memory impairment improved.
The researchers also looked at memory performance in pregnant women. Women later in pregnancy performed differently on certain memory tasks, and poorer performance was associated with higher estrogen levels.
That doesn’t mean we can say the exact same brain mechanism has been proven in humans..the detailed circuit was demonstrated in mice. But the human findings point in a similar direction and make the research especially interesting.
Does Pregnancy Brain Mean You’re Less Sharp?
No.
This is probably the part I would emphasize most.
The study did not show a general decline in intelligence or overall cognitive ability. The changes were more specific to certain aspects of memory.
Pregnancy is a period of major hormonal and neurological change, and some parts of brain function may temporarily work differently during that transition.
Other research has shown that pregnancy changes brain structure and connectivity in areas involved in social awareness, bonding, and responding to another person’s needs.
So rather than thinking of pregnancy brain as your brain “not working,” it may be more accurate to think of the maternal brain as being in a period of major adaptation.
That said, not every cognitive symptom during pregnancy should automatically be explained away as “pregnancy brain.”
When Is Brain Fog More Than Just Pregnancy Brain?
This is where reproductive psychiatry becomes especially relevant.
Memory and concentration are closely connected to mental health.
Poor sleep, anxiety, depression, stress, and emotional overload can all make it harder to concentrate and remember things.
For example, someone with significant anxiety may feel like her memory is worse, when in reality so much of her attention is being consumed by worry that she is not fully processing information in the first place.
Depression can also affect concentration, motivation, processing speed, and memory.
And of course, sleep disruption — which is extremely common during pregnancy and postpartum — can make all of this worse.
So if you are feeling more forgetful than usual, it is worth looking at the whole picture.
Are you sleeping well? Are you constantly anxious? Are you feeling overwhelmed, depressed, or emotionally exhausted? Is the brain fog mild and annoying, or is it actually interfering with work, relationships, or everyday functioning?
Those questions matter.
What Can You Do About Pregnancy Brain?
There is no specific treatment for the brain pathway identified in this study, but there are a few things that can make the experience easier.
Prioritize sleep as much as you realistically can.
Sleep has a huge impact on attention and memory. Pregnancy sleep is often imperfect, but significant insomnia or poor sleep quality is worth addressing.
Stop trying to keep everything in your head.
Use notes, reminders, calendars, lists, and alarms. This is not “giving in” to pregnancy brain. It is simply reducing unnecessary cognitive load.
Focus on one thing at a time when possible.
Multitasking feels efficient, but it often makes memory and attention worse — especially when your brain already feels stretched thin.
Take care of the basics.
Nutrition, hydration, movement, and overall physical health can all affect energy and cognitive function.
Pay attention to your mental health.
If anxiety, depression, or stress seem to be driving some of the fogginess, treating those symptoms may help your concentration too.
And most importantly, occasional forgetfulness does not mean you are becoming less intelligent, less capable, or less competent.
If the changes become severe, progressively worsen, or start interfering with your ability to function, talk with your healthcare provider rather than assuming it is simply part of pregnancy.
Sudden confusion or new neurological symptoms should always be evaluated promptly.
The Bottom Line
Pregnancy is changing much more than your body.
Your brain is also adapting to a completely different hormonal environment, and we are only beginning to understand how those changes affect memory, attention, emotion, and behavior.
This new research gives us a possible biological explanation for something women have been describing for years: pregnancy brain may be very real.
The goal is not to pathologize normal pregnancy changes, but it is also not helpful to dismiss a woman’s experience.
Sometimes forgetfulness is simply part of pregnancy. Sometimes it is being amplified by poor sleep, anxiety, depression, or stress. And sometimes it deserves a closer look.
Understanding the difference is part of taking maternal mental health seriously.
At Patel Mind and Body, our reproductive psychiatry services focus on women’s mental health throughout pregnancy, postpartum, and other reproductive transitions.
If you are experiencing persistent changes in mood, anxiety, concentration, sleep, or emotional well-being during pregnancy or postpartum, a reproductive psychiatric evaluation can help identify what may be contributing and what type of support would be most helpful.
Research referenced: Li X, et al. High-level estrogen impairs memory via estrogen receptor signaling in a hypothalamic-hippocampal neural circuit. Science Bulletin. Published online August 25, 2026. DOI: 10.1016/j.scib.2026.08.057.
This article is intended for educational purposes and does not replace individualized medical advice or evaluation.
