A second pregnancy may feel familiar. To the brain, however, it is a different experience altogether.
Research shows that first and second pregnancies reshape the maternal brain in measurably distinct ways—so distinct, in fact, that computer models can tell first-time mothers from second-time mothers simply by tracking how their brains changed between scans.
Each Pregnancy Leaves Its Own Neural Signature
The study, published in Nature Communications, tracked 110 women living in the Netherlands—40 first-time mothers, 30 second-time mothers, and 40 women who had never been pregnant for comparison—to analyze how successive pregnancies affect the brain in different ways.Researchers gathered brain imaging scans of participants, obtained before pregnancy and again around 80 days after birth, with a smaller subset scanned at roughly one year postpartum.
Both groups of mothers showed declines in gray matter volume, cortical thickness, and surface area compared to women who did not become pregnant—a pattern researchers interpret not as damage, but as remodeling. The changes were more extensive and slightly larger in first-time mothers.
The most pronounced reductions appeared in the default mode network, a system involved in self-reflection, social understanding, and thinking about others. Second-time mothers also showed changes in this network, but they were less pronounced. Researchers believe the changes reflect fine-tuning rather than loss of function, potentially helping mothers become more attuned to their babies’ needs.
“This network is primarily adapted during a first pregnancy and then further fine-tuned in subsequent pregnancies,” Hoekzema said. She suggested that the brain may be most sensitive to the surge of pregnancy hormones the first time around. “An already-transformed brain is slightly less sensitive to further hormone-driven remodeling.”
During pregnancy, rising hormones such as estrogen and progesterone help rewire the brain to support the emotional and social demands of motherhood. At birth, oxytocin joins in, consolidating the mother’s instinct to bond, protect, and nurture.
Interestingly, in second pregnancies, researchers observed stronger changes in the dorsal attention and somatomotor networks, which are systems responsible for directing attention to the external environment.
Nicole Kumi, founder of The Whole Mom, who wasn’t part of the study, told The Epoch Times that the findings are interesting because they mirror what they see in real life. “First-time mothers tend to turn inward, reflecting on who they are now, while second-time mothers are often operating in a more outward-focused mode, managing the needs of multiple children and a more complex family dynamic,” she said.
The changes also do not appear to disappear immediately after birth. Hoekzema noted that previous research from her group found some of the brain changes remained visible even six years after giving birth.
Why the Change
Brain patterns were distinct enough that computer models could classify women as having undergone a first or second pregnancy between scans with about 70 percent to 80 percent accuracy.They were even more accurate when distinguishing women who became pregnant from those who did not.
“Pregnancy is one of the most intense endocrine states in human life,” Dr. Amos Grünebaum, professor of obstetrics and gynecology at Northwell Health, told The Epoch Times, noting that the dramatic hormonal shifts of pregnancy are known to reshape the brain.
The Mental Load
Researchers also examined how brain volume changes related to maternal behavior and mental health, and the findings were nuanced. In first pregnancies, brain changes were tied to both prenatal attachment—the emotional connection to the unborn baby—and postpartum bonding, while in second pregnancies the link appeared only after birth.When it came to mood, smaller brain changes were linked to more depressive symptoms.
These findings are preliminary and represent the first evidence linking cortical changes during pregnancy to peripartum depressive symptoms, Hoekzema said.
Mental health experts say the emotional experience of pregnancy can also differ between first-time and experienced mothers.
In first-time mothers, mood symptoms often emerge after birth when expectations collide with the reality of sleep loss and feeding stress, Grünebaum said.
First-time mothers often struggle with identity disruption and experience it intensely after birth, Kumi said.
“Motherhood isn’t just the birth of a baby; it’s the birth of a mother,” she said. “Their routines, relationships, and sense of self shift almost overnight.”
In mothers who have been through it before, symptoms more often begin during pregnancy.
Why Early Screening Matters
The findings may carry practical implications for maternal care.Clinicians often focus screening for depression and psychological distress on the postpartum period, but the new research suggests that mental health symptoms can emerge earlier—particularly during a second pregnancy, Grünebaum said.
At the same time, he cautioned against over-interpreting the brain scans. Many of the structural changes likely reflect the brain’s normal adaptation for caregiving rather than indicating that something has gone wrong, he said. The study makes clear that the maternal brain is doing significant work long before and after birth.
Many mothers feel pressure to return to “normal” quickly.
“When mothers understand that this period is a developmental stage, not a personal failure, it changes everything,” Kumi said. Education and support during pregnancy and the postpartum period, she added, can help mothers navigate the transition better.
