Scientists finally found evidence that prove motherhood can indeed change a woman.

Findings of a new study have revealed long-lasting changes in the brain associated with pregnancy. The long-term changes in a pregnant woman's brain likely evolved to improve her ability to protect and nurture her child.

For the new study, Oscar Vilarroya, from the Autonomous University of Barcelona, and colleagues looked at the MRI scans of 25 women to compare their brain structures before and after their first pregnancies.

Gray Matter Pruning

Researchers found that after giving birth, the participants had significant reduction of gray matter in regions of the brain associated with social interaction and theory of mind. These brain regions also help humans think about what is going on in somebody else's mind. The researchers found that these same areas of the brain activate when mothers see images of their baby.

The loss of gray matter is not a bad thing, the researchers said. In fact, the changes, which last for at least two years after the birth of the baby, likely help women adapt to motherhood.

The shrinking of gray matter in certain areas of the brain after pregnancy is a phenomenon known as gray matter pruning. A similar reduction in gray matter is seen in early childhood and adolescence.

The gray matter is interconnected with neurons and during pruning, the most important connections are strengthened while the other are left to wither. Pruning in essence means that a brain region has become more specialized and does not at all indicate a loss of ability.

"The findings point to an adaptive process related to the benefits of better detecting the needs of the child, "Vilarroya said.

Pattern Of Gray Matter Loss Can Identify New Mothers

The changes in their brain predicted the women's scores on tests of maternal attachment. The results were so reliable a computer algorithm can determine which women were new mothers based on the pattern of gray matter that they lose.

"The changes were selective for the mothers and highly consistent, correctly classifying all women as having undergone pregnancy or not in-between sessions," the researchers wrote in their study. "The GM volume changes of pregnancy predicted measures of postpartum maternal attachment, suggestive of an adaptive process serving the transition into motherhood."

The changes in the brain were found to be similar whether women became pregnant naturally or through fertility treatments.

The findings were published in the journal Neuroscience on Dec. 19