Pregnancy alters women permanently: researchers have discovered the impact of childbirth on the female brain.

A new study conducted by scientists has provided fresh insights into how the human brain undergoes structural changes during pregnancy, particularly among first-time mothers. Researchers found that the volume of gray matter (GM) significantly decreases during pregnancy, especially in brain networks known as the "default mode network" and the prefrontal areas associated with self-referential thinking and social cognition, as reported by News Medical.

The scientists believe these changes may prepare the brain for motherhood. The volume of GM follows a U-shaped pattern: it decreases during the later stages of pregnancy and partially recovers six months after childbirth.

The study, published in the journal Nature Communications, involved 127 pregnant women at five different stages: before pregnancy, in the second trimester, in the third trimester, one month after childbirth, and six months after childbirth. MRI scans revealed that GM volume decreased by 2.7% in the second trimester and by 4.9% before delivery, while recovering by 3.4% after childbirth. However, this recovery did not return GM levels to pre-pregnancy status, suggesting that pregnancy may lead to long-term neurological adaptations.

To highlight pregnancy-specific effects, the data from these women were compared with those of 32 women who had never been pregnant and 20 non-pregnant mothers (partners performing caregiving duties but biologically not pregnant), none of whom exhibited similar brain changes.

Hormonal analysis indicated that the observed changes in GM volume were driven by fluctuations in pregnancy-related estrogen levels, particularly estriol sulfate and estrone sulfate, rather than parenting experience. Out of 49 analyzed hormones, only these two were closely linked to the reduction in GM volume during pregnancy and subsequent recovery. Functional MRI data did not reveal significant changes in brain network connectivity, suggesting that structural changes did not disrupt the overall organization of the brain.

The study also highlighted the role of maternal mental health in shaping these neurological adaptations. Researchers found that maternal well-being mediated more than 50% of the relationship between the recovery of GM volume postpartum and maternal attachment to the child. Mothers with higher levels of GM recovery in the postpartum period exhibited less hostility towards their children, while mothers experiencing postpartum depression or stress showed no significant impact on attachment and changes in GM volume.

These findings underscored the critical role of maternal psychological health in facilitating the neurological and emotional transition to motherhood. This, in turn, represents the first evidence supporting the hypothesis that GM volume during and after pregnancy follows a U-shaped trajectory. Although GM volume begins to recover after childbirth, the incomplete return to pre-pregnancy levels suggests that pregnancy may induce long-lasting brain adaptations that potentially enhance maternal caregiving.

The rigorous methodology of the study, which included MRI, hormonal profiling, and psychological assessments, established a solid foundation for future scientific inquiry into maternal brain changes and their implications for mental health.

Other research has also indicated that brain changes associated with pregnancy are not unique to humans. For example, studies on rodents have demonstrated similar hormonal influences on maternal behavior, strengthening the argument that these neurological shifts may be evolutionarily conserved.

Further research in this area will help determine whether these changes persist beyond six months postpartum and how they may influence long-term cognitive and emotional changes in mothers.

Important! This article is based on the latest scientific and medical research and does not contradict them. The text is for informational purposes only and does not contain medical advice. Always consult a physician for diagnosis.