Summary:
A Penn State study reveals that “pregnancy brain”, the common experience of forgetfulness, brain fog, and concentration lapses in expectant and new mothers, is strongly tied to underlying symptoms of anxiety and depression. While physical activity helped alleviate cognitive fog in women experiencing depressive symptoms, it unexpectedly worsened brain fog in postpartum mothers with high anxiety, suggesting that exercise driven by obligation can overburden an already stressed nervous system.
Key Facts:
- Emotional Drivers of Brain Fog: Symptoms of depression (hopelessness, low mood) and anxiety (excessive worry, sleep disruption) were significantly linked to higher rates of memory, attention, and language slips during pregnancy and the postpartum period.
- Exercise Nuance in Depression vs. Anxiety: Meeting physical activity guidelines (150 minutes/week) reduced brain fog in women reporting elevated depressive symptoms, but was associated with increased cognitive failures among highly anxious postpartum mothers.
- Overextension and Self-Care: Researchers caution that anxious new mothers may treat exercise as an added burden or pressure to lose weight, exacerbating cognitive fatigue, and emphasize that intentional self-care and social support are vital.
Source: Penn State
Expectant and new mothers have long described “pregnancy brain,” “baby brain,” or “momnesia”, a frustrating constellation of memory lapses, shattered focus, and absentmindedness. While not an official clinical diagnosis, the phenomenon is widely reported across pregnancy and the fourth trimester.
Seeking to determine whether routine physical activity could clear this cognitive haze, researchers at Pennsylvania State University launched a prospective study tracking women from late pregnancy into early motherhood. Their findings, published in Psychology & Health, reveal a far more intricate dynamic between emotional states, exercise habits, and mental clarity than previously understood.
Rather than acting as a universal antidote to brain fog, physical activity produced contrasting outcomes depending on whether a woman was dealing with symptoms of depression or anxiety.
Mood Symptoms Mirror Cognitive Slips
The research team evaluated 56 women in Central Pennsylvania at approximately 30 weeks of pregnancy, following up with 46 of the participants six weeks postpartum. The participants completed standardized assessments measuring physical activity levels, depressive symptoms, anxiety levels, and self-reported cognitive failures in memory, attention, and language.
Across both gestational and postpartum assessments, mental health symptoms strongly tracked cognitive disruption.
“Symptoms of anxiety, including excessive worrying, trouble sleeping and concentration problems—and symptoms of depression, including hopelessness, worthlessness and loss of appetite—were associated with higher levels of pregnancy brain fog in our study,” said first author Victoria Suhy, a doctoral candidate in kinesiology at Penn State.
The Divergent Impact of Physical Activity
When researchers analyzed exercise against cognitive performance, general physical activity alone did not produce a statistically significant reduction in brain fog across the entire cohort. However, when stratified by specific emotional symptoms, clear patterns emerged:
- Depression Relief: Among women with high levels of depressive symptoms, meeting the American College of Obstetricians and Gynecologists (ACOG) guidelines of 150 minutes of moderate-intensity activity per week was associated with noticeably lower levels of brain fog.
- Anxiety Exacerbation: Conversely, among postpartum mothers experiencing high levels of anxiety, meeting exercise guidelines was linked to an increase in cognitive slips and memory lapses.
“We expected physical activity would reduce forgetfulness and memory lapses, but the reality is more nuanced,” Suhy explained. “Exercise may indirectly decrease brain fog for women with depression symptoms, but it may exacerbate cognitive failures for women with symptoms of anxiety. There is a complex constellation of factors that drive this phenomenon. If we want to help new moms clear brain fog, it will take more than physical activity; we must encourage robust self-care.”
The investigators suggest that anxious new mothers may feel compelled to exercise out of perceived duty or pressure to rapidly shed gestational weight, turning a beneficial activity into an exhausting chore.
“It is possible that new mothers who are more anxious and who meet activity guidelines may be stretching themselves too thin,” Suhy noted. “They may be trying to do too much, which would explain how meeting guidelines could be an added burden. If a woman feels anxious and is engaging in physical activity out of a sense of obligation or a desire to drop pregnancy weight, it might actually increase the number of times that your brain slips.”
Reframing Postpartum Recovery and Support
The findings highlight the importance of viewing physical activity through an individualized lens during perinatal transitions. For women coping with low energy, apathy, or depressive feelings, movement can stimulate neuroplasticity and boost cognitive alertness. But for women already in a state of sympathetic hyperarousal from anxiety, adding rigid workout schedules can overdraw depleted cognitive reserves.
“Because of the many obligations that women often have, the idea of self-care is sometimes thought of as being ‘selfish’ rather than essential, especially during pregnancy and postpartum when women are more vulnerable to cognitive fog and emotional changes,” said senior author Danielle Symons Downs, PhD, professor of kinesiology and obstetrics and gynecology and associate director of the Penn State Social Science Research Institute.
“Women need to understand that self-care and self-monitoring are necessary components of motherhood—even if it is only finding five minutes in the morning and five minutes before bed to scan your feelings—to track and become more aware of whether you are experiencing any significant mood shifts or more severe cognitive failures,” Downs added.
The researchers urge partners, family members, and clinicians to provide tangible support structures that allow new mothers the space to rest, recover, and engage in genuine restorative care.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this Alzheimer’s disease Research:
- Media Contact: Aaron Wagner
- Source: Penn State
- Image Credit: Image credited to Neuroscience News
- Original Research is Open Access: Psychology and Health (Oct 1, 2026). “Pregnancy brain? Relationships between meeting prenatal physical activity guidelines, stress, anxiety, cognitive functioning in pregnancy and postpartum.” Authors: Victoria A. Suhy, Abigail M. Pauley, Owen Griffith, Jamie Whitney, and Danielle Symons Downs.
- DOI: 10.1080/08870446.2026.2733983
Abstract
Pregnancy brain? Relationships between meeting prenatal physical activity guidelines, stress, anxiety, cognitive functioning in pregnancy and postpartum
Objective
Meeting physical activity (PA) guidelines and regulating mood may protect perinatal women from cognitive changes, however, scant research has examined these factors. This study examined whether PA and mood (anxiety/depressive symptoms) were associated with pre-and postnatal cognitive failures (perception/memory/action lapses).
Methods and Measures
Pregnant women (N = 56) from a longitudinal cohort study completed measures at 28–30 wks gestation and 6 wks postpartum. To track within-person PA/mood patterns from pregnancy to postpartum, women were grouped by PA guideline adherence and mood symptoms at both, one, or neither timepoint. General linear models assessed associations; exploratory analyses examined whether PA modified relationships.
Results
Higher prenatal mood symptoms were associated with greater prenatal and postpartum cognitive failures. Although PA was not directly associated with perinatal cognition, PA moderated prenatal mood-cognitive failures associations such that cognitive failures increased with depressive symptoms at a lower rate for the meet PA guidelines group and increased with anxiety symptoms at a lower rate for the not meet postpartum PA guidelines.
Conclusion
Better perinatal mood regulation was associated with fewer cognitive failures. Meeting PA guidelines may help women regulate the mood-cognitive failures relationship in pregnancy, but may not have the same impact in postpartum. Future research should examine dynamical changes in PA, mood, and cognitive failures to identify effective interventions and understand long-term impacts of childbirth on maternal cognition.
