An earlier study by Elseline Hoekzema was the first to demonstrate that pregnancy changes the structure of the human brain. The research group also demonstrated that pregnancy changes the functioning of the brain. For the follow-up study, the results of which have now been published, 110 women were monitored: some were becoming mothers for the first time, others were having their second child, and a third group remained childless. Brain scans before and after pregnancy showed what changes occurred in the brain. “We have shown for the first time that the brain not only adapts during the first pregnancy, but also during the second,” says Hoekzema, head of the Pregnancy Brain Lab at Amsterdam UMC.
Different brain networks
The biggest changes during a first pregnancy occurred in the structure and activity of the so-called Default Mode Network. This part of the brain is important for many functions, including self-reflection and social processes. During a second pregnancy, this network changed again, but less dramatically. However, during a second pregnancy, there were more changes in brain networks related to paying attention and responding to stimuli. “It seems that during a second pregnancy, the brain changes more significantly in networks involved in responding to sensory stimuli and directing your attention,” explains researcher Milou Straathof, who analyzed the data. “These processes can be beneficial when caring for multiple children.”
Mental health of mothers
The researchers also found a connection between the changes in the brain and the bond between mother and child. This link was more prominent in the first pregnancy than during the second pregnancy. In addition, the researchers observed links between structural brain changes and peripartum depression, both during a first and a second pregnancy. This provides the first evidence that the changes that occur in a woman's cerebral cortex during pregnancy are related to depression. In women who became mothers for the first time, this was particularly noticeable after giving birth. In women who had their second child, this was the case during pregnancy. “This knowledge can help us to better recognize and understand mental health issues in mothers. We must understand how the brain adapts to motherhood.”
The importance of research into the maternal brain
This study provides new insights into how the female brain adapts to motherhood and contributes to closing this important knowledge gap about female biology. Hoekzema: “The majority of women become pregnant one or more times in their lives, but only now are researchers beginning to unravel how this affects the female brain.” The results may also contribute to better care for mothers, for example, in the prevention and treatment of postpartum depression. The study also shows that the brain is flexible and can continually adapt to major changes in life.
Read the publication in Nature Communications: The effects of a second pregnancy on women’s brain structure and function
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