According to a new study, when women become pregnant, their brain structures change for at least two years.
Researchers from Universitat Autonoma de Barcelona believe that the changes to the brain help mothers prepare for some key parenting challenges.
“The findings point to an adaptive process related to the benefits of better detecting the needs of the child, such as identifying the newborn's emotional state,” said the study’s co-lead author Oscar Vilarroya in a statement.
The study, published Monday in the journal Nature Neuroscience, was conducted over a five-year period and compared MRI brain scans of 25 first-time mothers, before and after their pregnancies, to a group of 20 women who had never been pregnant.
Vilarroya and his team found that brains of women who had been pregnant had noticeably less grey matter in areas of the brain associated with how you think about others and how you think about yourself.
It's not clear what the reduction in grey matter means. It could either be a loss of brain cells or a pruning of the places where brain cells communicate, called synapses.
Losing some synapses is not necessarily a bad thing. For example, it happens during a hormonal surge in adolescence, producing more specialized and efficient brain circuits. The researchers suspect that a similar transformation could be happening in the pregnant women.
According to Erika Barba, the other co-lead author, "these changes concern brain areas associated with functions necessary to manage the challenges of motherhood".
In fact, researchers found that the areas with grey matter reductions were the same brain regions that lit up when the mothers of the study saw pictures of their own babies.
The researchers also investigated whether fertility treatments or natural conception would change how the brain would morph, but they found that the reductions in grey matter were practically identical, no matter how children were conceived.
Researchers did not observe any changes in memory or other mental functions during the pregnancies, commonly referred to as pregnancy brain. So the loss of grey matter doesn’t imply any cognitive deficits.
According to Vilarroya, the research helps explain the neural transformation of motherhood, including mental health changes, like post-partum depression, before and after the baby is born.
One of the researchers, Susanna Carmona, told CTVNews.ca that knowing what a “normal” pregnancy brain looks now means they make comparisons to the brains of people with mental illnesses.
“In future research we can analyze the change in brain volume in people who have post-partum depression and compare and then help prevent it,” she said.
The study also sheds new light on how the brain can change and adapt in general, but more research is needed to understand exactly what is causing the changes and why.
Although, they think the differences might be a result of the sex hormones that flood the brain during pregnancy.
“There are a million questions,” Carmona said in a telephone interview, citing examples like what happens to the brain during the second pregnancy, “we need more research to answer those questions.”
