Pregnancy causes dramatic brain changes, study finds

A new study published in the journal Nature Communications has shown that a woman's brain undergoes drastic changes during pregnancy. The brain loses some of its gray matter and also changes the dormant mode network of the brain, an area that remains active in the background. LiveScience writes about the discoveries of the staff of the University of Amsterdam. Scientists believe that such neurological changes may help bond between mother and child and contribute to the change in identity that many new mothers experience.

In an earlier study of pregnant women in Spain, the same group of scientists found that the participants experienced a decrease in the amount of gray matter in their brains, and this lasted up to two years after giving birth. This time, the researchers followed 80 Dutch women, 40 of whom became pregnant during the study. All had brain scans at baseline and at various times thereafter, including (for those who became pregnant) shortly after delivery and one year after delivery.

Women who become pregnant lose their gray matter after giving birth. But this fact cannot be regarded as negative, according to the researchers: rather, it means “fine tuning” of the brain, which is useful when caring for a newborn.

The study also showed that women who became pregnant experienced changes in the brain's dormant mode network, a group of brain regions that remain active when a person is not performing a specific task. This network is active when you allow your mind to wander, and is also believed to be involved in self-reflection and empathy.

Curiously, women with greater changes in the default brain network felt a stronger connection with their infant and enjoyed interacting with him more, less resentment or anger towards the child. In addition, such changes in the brain led young mothers to see their fetus as a person.

The researchers concluded that hormones were responsible for these changes: Women with higher levels of estrogen had greater brain changes. However, the possibility that other factors, including exercise, nutrition, and genetic markers, may also influence this cannot be ruled out.