The Science of Mom Brain: Why Pregnancy Makes You Forget Everything (and How You Get It Back)

If you’ve ever stared at your phone’s GPS, standing two blocks from your destination, and somehow still couldn’t figure out where to go… welcome to the club, mama.

During pregnancy and postpartum, I felt like my brain packed up, left for maternity leave early, and forgot to tell me where it went. What started as a little forgetfulness in my second trimester turned into full-blown “mom brain” that made even basic problem-solving feel impossible.

But here’s the good news: it does come back. Slowly, surely, beautifully—and in my case, stronger than ever.

The Science Behind “Baby Brain”

If you’ve felt like pregnancy turned your sharp mind into mashed potatoes, you’re not imagining things. Studies show that up to 80% of pregnant women report increased forgetfulness or mental fog.

Neuroscientists have actually found structural changes in the brain during pregnancy—especially in areas tied to social and emotional processing. According to a 2016 study published in Nature Neuroscience, these changes help mothers bond with their babies and become more attuned to their needs.

In other words, your brain isn’t shrinking—it’s rewiring. Your cognitive bandwidth gets reallocated toward protecting, nurturing, and connecting with your baby. It’s survival-level multitasking, not a flaw.

When My Brain Left the Building

For me, mom brain really hit around week 16.During the first trimester, I was miserably sick—throwing up daily, exhausted, migraine-ridden—but my brain? Sharp as ever.

Then suddenly, little memory lapses started creeping in.By week 18, I was forgetting simple things. Once, in the middle of a conversation with friends, I literally forgot my middle name. My husband had to fill in the blank for me.

By week 26, it went from “oops, I forgot that thing” to “why can’t I think straight?”

I’ll never forget (ironically) being two blocks from a restaurant for a friend’s birthday dinner. I had GPS in hand, street signs in front of me, and still—nothing was clicking. I ended up calling my mom (4,000 miles away) in tears. Finally, another mom saw me struggling and walked me to the door.

That’s the day I realized: this wasn’t just forgetfulness. My brain was temporarily offline.

How Work (and Life) Got Weird

At the time, I was still working full-time. I hadn’t made any major mistakes, but I could feel how fragile my mental clarity had become. So, I did what any responsible (and humble) pregnant woman would do: I told my boss I needed her to double-check my work.

She was understanding—at first. But I could sense the tension. Eventually, I decided to start my maternity leave a week early just to rest.

I used to joke, “From 35 weeks on, I couldn’t drive my way out of a paper bag.” It was funny because it was true.

Postpartum: Slowly Coming Back Online

Here’s the part I wish more people talked about: your brain doesn’t magically reset when the baby arrives.

Immediately after delivery, I’d say I was operating at about 30% capacity—up from 10% during late pregnancy. It sounds small, but that 20-point jump felt huge.

Month by month, I felt my cognitive gears turning again. At 4 months postpartum, when I returned to work, I was maybe 70% there. By 13 months postpartum, I finally felt like myself again—100%.Now, at 19 months postpartum, I’d honestly say I’m at 110%. I feel sharper, wiser, and more emotionally grounded than before motherhood.

Breastfeeding and the Brain Fog

If you’re breastfeeding, you’re running a cognitive marathon on no sleep.

Research shows that prolactin and oxytocin—the hormones that support milk production and bonding—also influence brain chemistry. They can enhance calm and attachment, but combined with sleep deprivation, they can blur your cognitive edges.

One 2021 study found that mothers who exclusively breastfed longer sometimes reported greater fatigue and slower mental processing, but also higher emotional regulation and multitasking ability. So it’s a trade-off: your brain may feel foggy, but it’s working overtime in other areas to keep you (and baby) connected.

Personally, I was exclusively breastfeeding and handling all overnights. No surprise—sleep deprivation did not help.

But interestingly, even while still nursing 1–2 times a day, I now feel sharper than I did before pregnancy.

On nights I get 8 hours of sleep, my mind feels crystal clear.

I’m curious to see how my brain feels once I fully wean, but so far, I feel like my neurons have gone through mom boot camp—and come out stronger.

For Every Mom in the Fog

If you’re reading this and wondering when you’ll feel “normal” again—hang in there.You’re not broken. You’re becoming.

Your brain is doing something extraordinary: rewiring itself to love, protect, and understand another human being. It takes time to balance the new circuits, but it does happen.

And while I can’t personally recommend any supplements (since I haven’t tried them), my friend swears by a memory supplement she got from her local pharmacy that she said worked wonders. If you’re near a health-food or vitamin store, it might be worth walking in and asking what they recommend. Sometimes even just talking to someone about it feels empowering.

The Takeaway

Pregnancy and postpartum change your brain—but not in the way you think.It’s not a loss of intelligence; it’s a recalibration of priorities.

With rest, nutrition, support, and time, your clarity will return—and maybe, like me, you’ll find that motherhood didn’t make you lose your mind… it just made you rebuild it differently.

So if you’re in the thick of the fog right now, please know: you’re not alone. Your brain is coming back. And she’s coming back wiser than ever. 💛

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Sources

• Hoekzema, E. et al. (2016). Nature Neuroscience: “Pregnancy leads to long-lasting changes in human brain structure.”

• de Groot, R.H. et al. (2021). Psychoneuroendocrinology: “Pregnancy and postpartum brain plasticity and maternal cognition.”

• Henry, J.D. & Rendell, P.G. (2007). Journal of Clinical and Experimental Neuropsychology: “A review of the cognitive changes during pregnancy and postpartum.”