Pregnancy brings profound changes to nearly every system in the body, including the brain. For years, researchers have been interested in understanding whether these changes have long-term implications for brain health, particularly as it relates to dementia risk later in life.

One reason scientists have focused on pregnancy is the growing evidence that reproductive hormones may influence neurodegenerative disease risk. As Dr. Kellyann Niotis explains, “One of the drivers for investigating estrogen as being a neuroprotective chemical or substance for the brain has been, women who have a longer reproductive year have more estrogen exposure in their life, and they have potentially a lower risk of Alzheimer’s disease.”

Research has also identified an intriguing relationship between childbearing and dementia risk. According to Dr. Niotis, studies suggest that women who have had between one and five children may be less likely to develop dementia later in life. While researchers are still working to understand why, the answer may involve a combination of hormonal changes, structural brain adaptations, and the cognitive demands of parenting.

Is “Mommy Brain” a Real Thing?

Many new mothers describe feeling forgetful, distracted, or mentally scattered during and after pregnancy, a phenomenon commonly referred to as “mommy brain.” While often dismissed as a cultural stereotype, emerging research suggests there may be a biological basis behind the experience. Dr. Niotis notes that imaging studies (Hoekzema et al. 2017) have examined women’s brains before and after pregnancy and found measurable structural changes. 

As she explains, “there really is a mommy brain, and this mommy brain is related to how the brain structure changes.” Importantly, these changes do not necessarily indicate cognitive decline. In fact, they may reflect an adaptive process that helps prepare the brain for motherhood. Researchers have observed reductions in gray matter volume in specific regions involved in social cognition, the ability to understand emotions, interpret social cues, and respond to the needs of others. These same regions are relevant to discussions about cognitive aging and Alzheimer’s disease, making the findings particularly intriguing. Even more remarkable, these structural changes persisted well beyond pregnancy. Dr. Niotis explains that researchers followed participantsup to two years postpartum and continued to observe the same brain changes.

When Brain Changes Are a Good Thing

At first glance, the idea of losing gray matter may sound concerning. Gray matter contains the cell bodies of neurons and is often associated with cognitive function. In many neurological studies, reductions in brain volume are viewed as a negative sign. However, pregnancy may be an important reminder that not all brain changes are harmful. 

As Dr. Niotis explains, “sometimes when we see brain volume changes, it could actually represent new or tighter neuronal connections and reconfigurations of neuronal networks.” Rather than reflecting degeneration, these changes may represent the brain becoming more specialized and efficient. She adds that “it could be an adaptive process that’s happening,” highlighting the importance of interpreting brain imaging findings within their broader biological context. These observations have led researchers to explore whether pregnancy-related brain adaptations may contribute to the lower dementia risk observed among women who have had children.

Balancing Parenthood and Brain Health

One of the most fascinating aspects of this research is that the potential benefits appear despite many of the challenges that accompany raising young children. New parents often experience disrupted sleep, reduced time for exercise, changes in diet, less social engagement outside the family, and fewer opportunities for hobbies or intellectual pursuits. Many of these factors are typically considered important for maintaining long-term brain health.

Yet, as Dr. Niotis points out, studies continue to show that “women who have had between one and five children seem to be at a lower risk of Alzheimer’s disease.” Researchers do not yet know exactly why. The protective effect may stem from hormonal changes during pregnancy, structural brain adaptations, the cognitive demands of parenting, or some combination of all three. As Dr. Niotis explains, “whether that relates specifically to these hormonal elevations that happen during pregnancy, or structural brain changes that happen during pregnancy, or the cognitive benefits that can happen during raising children,” there appears to be something about the experience that may help offset some of the lifestyle challenges that often accompany early parenthood.

Giving Yourself Grace During the Early Years

For many parents, especially mothers of infants and young children, maintaining ideal health habits can feel nearly impossible. Sleep is interrupted, schedules become unpredictable, and finding time for exercise or self-care can be a challenge. Dr. Niotis encourages a more compassionate perspective. “My advice is, don’t become overwhelmed. Don’t feel guilty about not being able to do, to sleep as much as you once were, or to exercise for an hour. Do what you can when you can. Eventually you’ll get back there.” Rather than striving for perfection during this demanding stage of life, she emphasizes the importance of focusing on what matters most. “It’s more important to prioritize your social interactions and your family time during this amazing period of your life, than it is for making sure that you know you’re getting your eight hours of sleep.”

While healthy habits remain important throughout life, the research surrounding pregnancy and brain health offers a reassuring message: the changes occurring during this unique period may be doing more for the brain than we once realized. As scientists continue to investigate the relationship between motherhood and dementia risk, evidence increasingly suggests that pregnancy is not simply a physical transformation—it may also leave a lasting imprint on the brain itself.

For more insights on the impact of pregnancy on brain health, watch our full conversation with Dr. Niotis in the video above.

By Alicia Barber Minteer, PhD