All you kneed to know about the "Pregnancy Brain"

• “Pregnancy brain” isn’t just a figment of the imagination; it can be detected through structural changes in the brain
• The brain’s gray matter decreases during pregnancy, while the cavities (ventricles) enlarge
• Language and memory skills may be particularly affected, but intelligence and planning abilities remain intact
• These changes appear to be beneficial for strengthening the mother-child bond and making you an even better mom

Where did I put my keys? What was I supposed to buy? Many expectant moms know the feeling of their mind becoming an unreliable mess during pregnancy. The phenomenon known as “pregnancy brain” has received a lot of attention online, especially in recent years. Pregnant women report increased forgetfulness and “slow thinking” during pregnancy. While some women simply laugh at their own struggles, these changes seem to be a real daily challenge for others. But where do these changes come from, and is there any truth to them at all? Join us on a journey into neuroscience to settle the question once and for all. 

Anatomy in Transition: What Happens in an Expectant Mother’s Brain

Hard to believe, but true: An expectant mother’s brain actually differs structurally from that of a woman without children!

During pregnancy, the gray matter in the pregnant woman’s brain decreases significantly. The thickness of the cortex is also reduced (Pritschet, L., et al., 2024). Gray matter is located mainly at the “edge” of the brain and is responsible, among other things, for higher cognitive functions, sensory perception, motor skills, memory, and emotions. The cortex consists mostly of gray matter and is also referred to as the “cerebral cortex.” It is, therefore, the outermost layer of the brain.

At the same time, it was found that pregnancy causes the ventricles to enlarge and the volume of cerebrospinal fluid to increase (Pritschet, L., et al., 2024). On the one hand, the ventricles produce cerebrospinal fluid, and on the other hand, they are themselves filled with it. They are thus cavities that are not filled with nerve cells. Cerebrospinal fluid is responsible for many different functions: on the one hand, it protects the brain from impacts, and on the other hand, it is important for nutrient supply and waste removal.

Other studies have found that differences in brain structure become particularly pronounced in the later stages of pregnancy (Paternina-Die, M., et al., 2024).

In women who had given birth just a few days earlier, it was also found that new mothers had less gray matter in certain areas of the brain, such as the hippocampus or the frontal lobe. Thinning of the cortex was also detected a few days after birth (Chechko, N., et al., 2022).

So the brain clearly adapts to the unique circumstances of pregnancy! But does this explain the well-known forgetfulness and other difficulties?

How these brain changes affect your daily life

Just last year (2025), it was impressively demonstrated that pregnant women perform worse on the so-called MoCA test (Montreal Cognitive Assessment) than non-pregnant women. This test was developed to detect cognitive impairments and dementia at an early stage. Based on the poorer test results, it can be concluded that expectant mothers are indeed less cognitively capable than other women. It was also specifically noted that pregnant women achieved below-average results in the area of language skills (Ali, S.A., et al., 2025). This “side effect” of pregnancy is likely to sound familiar to many women…

Other studies have also demonstrated a decline in cognitive performance among pregnant women. These studies found that, in addition to language skills, memory may also be impaired. For some expectant mothers, the speed at which they process information also appears to be slower than it was before pregnancy (Younis, J., et al., 2025).

There is good news, however, even if you are now seriously concerned about your mental state: the planning ability and, in particular, the intelligence of the women studied were not diminished by their pregnancy (Younis, J., et al., 2025)! So while pregnant women may occasionally face a minor hurdle due to changes in the brain, ultimately, pregnancy does not make you “dumb” by any means!

Mystery solved? Causes of “pregnancy brain”

Unfortunately, “pregnancy brain” has not yet been fully researched and remains a mystery in many respects. Some experts are relatively certain that the cause lies primarily in estradiol. Estradiol is a hormone that always plays an important role in women’s bodies, but is found in higher concentrations than usual during pregnancy (Hoekzema, E., et al., 2022).

Other scientists do not consider the matter to be conclusively settled and acknowledge the validity of other theories as well. For example, in addition to hormones, an energy deficit in pregnant women could also be responsible for the reduced cognitive abilities. Your baby’s growth requires an enormous amount of additional energy, and the female body might simply allocate less energy to the brain in order to have enough for the baby. So it should come as no surprise that the brain performs less effectively with less energy. However, the body may also simply be prioritizing—even though enough energy is available. From a purely biological perspective, it is certainly questionable whether superior cognitive abilities are actually necessary during pregnancy or whether other bodily functions are not more important (Younis, J., et al., 2025).

Meaningful Chaos in the Brain for Super Moms

Now that it is clear that the brain changes during pregnancy and that this comes with disadvantages for the women affected, the question naturally arises as to why this has to happen and whether there isn’t a better solution. Amid all the mess and chaos caused by these structural changes, it has been found that these changes actually make you a better mom! It sounds crazy and probably doesn’t make sense at first glance. But upon closer inspection, scientists realized the upside of it all: this new structure in your brain helps you build a stronger bond with your little miracle! It also makes it easier for you to respond to your baby! So all those annoying changes seem to be quite positive after all, and maybe this thought will help you when you find yourself getting frustrated with yourself and your “pregnancy brain” again (Younis, J., et al., 2025).

Will the forgetfulness last forever?

Of course, you’re now wondering whether you’ll remain forgetful forever after giving birth—a very valid question. Unfortunately, this is a question that’s difficult to answer. It has already been found that even six years after pregnancy, it’s possible to tell from the brain structure whether a woman was pregnant or not! Pretty fascinating! Of course, the brain can still change even six years after pregnancy, but the study authors assume that these changes may persist for life (Martínez-García, M., et al., 2021).

However, other researchers have found that after childbirth, the brain undergoes another change and appears “younger” than it did before pregnancy (Luders, E., et al., 2022).

In conclusion, it can only be said that further research is needed, and it is not yet clear at all whether—or to what extent—these (potentially existing) brain changes continue to affect women’s cognitive performance after pregnancy.

Frequently asked questions on the topic

What exactly is “pregnancy brain”?

It refers to increased forgetfulness, difficulty finding the right words, and a perceived slower ability to process information during pregnancy.

Does pregnancy make you less intelligent?

No! Studies show that neither general intelligence nor planning ability decreases. Only specific areas such as short-term memory or language skills are temporarily impaired.

Why does the brain change at all?

Nature optimizes the brain for motherhood. These structural changes help build a closer bond with the child and respond more quickly to the baby’s needs.

Does forgetfulness go away after giving birth?

This is not yet fully understood. While some changes in brain structure remain detectable for years, other studies show that the brain undergoes regeneration processes again after childbirth. However, most moms report that the “fog” in everyday life clears up again after the hormonal changes subside.

References

• Pritschet, L., Taylor, C. M., Cossio, D., Faskowitz, J., Santander, T., Handwerker, D. A., Grotzinger, H., Layher, E., Chrastil, E. R., & Jacobs, E. G. (2024). Neuroanatomical changes observed over the course of a human pregnancy. Nature neuroscience, 27(11), 2253–2260. https://doi.org/10.1038/s41593-024-01741-0
• Paternina-Die, M., Martínez-García, M., Martín de Blas, D., Noguero, I., Servin-Barthet, C., Pretus, C., Soler, A., López-Montoya, G., Desco, M., & Carmona, S. (2024). Women's neuroplasticity during gestation, childbirth and postpartum. Nature neuroscience, 27(2), 319–327. https://doi.org/10.1038/s41593-023-01513-2  
• Chechko, N., Dukart, J., Tchaikovski, S., Enzensberger, C., Neuner, I., & Stickel, S. (2022). The expectant brain-pregnancy leads to changes in brain morphology in the early postpartum period. Cerebral cortex (New York, N.Y. : 1991), 32(18), 4025–4038. https://doi.org/10.1093/cercor/bhab463
• Ali, S. A., Sualeh, M., Raza, G., Sabeeh Ul Haq, M., Hissan, L., Zafar, D., Adnan, M., & Ali, S. K. (2025). Exploring the impact of pregnancy on cognitive function: a comparative study in a low-income setting. BMC pregnancy and childbirth, 25(1), 447. https://doi.org/10.1186/s12884-025-07539-7
• Younis, J., Bleibel, M., Masri, J. E., Ismail, A., & Abou-Abbas, L. (2025). Exploring the influence of pregnancy on cognitive function in women: a systematic review. BMC pregnancy and childbirth, 25(1), 88. https://doi.org/10.1186/s12884-025-07181-3
• Hoekzema, E., van Steenbergen, H., Straathof, M., Beekmans, A., Freund, I. M., Pouwels, P. J. W., & Crone, E. A. (2022). Mapping the effects of pregnancy on resting state brain activity, white matter microstructure, neural metabolite concentrations and grey matter architecture. Nature communications, 13(1), 6931. https://doi.org/10.1038/s41467-022-33884-8
• Martínez-García, M., Paternina-Die, M., Barba-Müller, E., Martín de Blas, D., Beumala, L., Cortizo, R., Pozzobon, C., Marcos-Vidal, L., Fernández-Pena, A., Picado, M., Belmonte-Padilla, E., Massó-Rodriguez, A., Ballesteros, A., Desco, M., Vilarroya, Ó., Hoekzema, E., & Carmona, S. (2021). Do Pregnancy-Induced Brain Changes Reverse? The Brain of a Mother Six Years after Parturition. Brain sciences, 11(2), 168. https://doi.org/10.3390/brainsci11020168
• Luders, E., Kurth, F., & Sundström Poromaa, I. (2022). The neuroanatomy of pregnancy and postpartum. NeuroImage, 263, 119646. https://doi.org/10.1016/j.neuroimage.2022.119646