Is 'Mommy Brain' Real? New Study Offers a Biological Explanation
Many expectant mothers notice they become more forgetful or have difficulty concentrating during pregnancy — a phenomenon often called 'mommy brain' or 'pregnancy brain.' A new study published in Science Bulletin may offer a biological explanation.
Mouse Study: How Estrogen Affects Memory
Researchers in Texas and China used mice to mimic the elevated estrogen levels seen during pregnancy. The animals developed temporary memory problems without changes in mood.
The scientists found that sustained high levels of estrogen during pregnancy can disrupt a specific brain pathway involved in memory. High estrogen increased activity in GABA-releasing neurons in the lateral hypothalamus, which project to the hippocampus and affect memory-related activity.
- When researchers blocked the pathway between the two regions, the mice no longer experienced estrogen-related memory problems.
- Activating the pathway caused memory problems even without elevated estrogen.
70 Women Tested: Memory Difficulties Most Apparent in Late Pregnancy
The team also assessed memory performance in 70 women, including non-pregnant controls and pregnant women in each trimester. They used cognitive tests to assess long-term memory, short-term memory, and working memory.
Overall, the pregnant group performed worse on simple tests that rely heavily on memory, which correlated with circulating estrogen levels, while being less affected on more difficult tasks involving complex executive functions. Memory difficulties were most apparent during late pregnancy.
Expert: Changes Are Temporary, Not a Decline in Intelligence
Dr. Zheng Sun, an associate professor of medicine at Baylor College of Medicine and one of the study leaders, told FOX Local: 'I don't want this to be overinterpreted as suggesting that pregnancy is bad for the brain. The current tests suggest that the effects in humans are modest, and the mouse data suggest that they are relatively short-lived.'
The researchers emphasized that the study did not directly manipulate or measure the specific neural circuit in pregnant women, meaning the human findings support the hypothesis but do not establish the same level of causality as the mouse experiments. The study also did not determine how quickly memory returns after childbirth.
Previous Studies Link Pregnancy to Brain Changes
Previous studies have shown that pregnant women may report some degree of forgetfulness or cognitive changes. One study published last year in BMC Pregnancy and Childbirth suggested that pregnancy modestly affected verbal memory and attention compared to non-pregnant controls, with indications that the decline persisted postnatally.
Another study published in Nature Communications found that gray-matter volume decreased by up to 4.9% during pregnancy, with partial recovery postpartum. The changes occurred across 94% of the brain's gray-matter volume and were especially prominent in regions associated with social cognition.
Tips for Coping with 'Pregnancy Brain'
- Maintain a regular sleep schedule and get adequate rest
- Use notes, calendars, and reminders to support memory
- Exercise moderately to help improve cognitive function
- Eat a balanced diet rich in Omega-3, folate, and other nutrients
- Consult a doctor if memory problems significantly affect daily life
The Xiaoshu Health App can sync with Apple Health to track relevant metrics, helping expectant mothers better understand their body changes and manage pregnancy health scientifically.