How pregnancy changes a woman’s brain

A study published a few days ago in the journal Science had, to put it mildly, a headline: During pregnancy, a woman’s brain size decreases. In particular, they said, he lost volume in his gray matter and frontal cortex. The truth is that there is no reason to worry. It was already known that this decline had occurred. “What’s new is that they traced this process in detail that was hitherto unknown,” explains Susana Carmona, neuroscientist and author of the book Neuromaternal, where she explains in simple terms what exactly happens in the most complex organ. human being.

“We are uncovering the tip of the iceberg,” warns an expert who has been studying the area since 2017. It is obvious that the female body undergoes radical changes during pregnancy. In fact, he does nothing more than adapt to be able to accommodate the child and give birth – two processes that are not at all simple. The list of alterations could be listed almost endlessly. The endocrine, cardiovascular, respiratory, urological, hematological, skeletal and nervous systems are affected. All this means that in addition to weight gain as the baby grows, his heart pumps 40% to 50% for the needs of the uterus; that the blood volume increases to one liter – a lot, considering that normally it ranges from 4.5 to 6 liters; let your heart rate rise; let them pee more…

As for hormones, it’s the same. The production of estrogen and progesterone will increase almost a thousand times. The first helps, among other things, the maturation of fetal bones and stimulates breast growth, promoting milk production. Progesterone, for example, prepares the endometrium so that it can shelter and nourish the fetus.

Child care

Doctors and, directly and intuitively, pregnant women know all this very well. Changes in the brain have only recently become known. As already mentioned, the amount of gray matter and the volume of the cerebral cortex decreases. “Gray matter is where neurons and glia are located – cells that basically help neurons function properly and which are being studied for their role in diseases such as Parkinson’s disease, Alzheimer’s disease or multiple sclerosis. White matter contains axons, which are highways for transmitting information between brain cells,” Cardona explains. “The cerebral cortex is what distinguishes the mammalian brain. In humans it is particularly developed,” describes Fernando García Moreno, an Ikerbasque researcher at the Basque Center for Neurosciences of Achucarro.

As mentioned, this reduction is not a problem. “Brain atrophy is usually associated with cognitive deficits, but this is not the case,” says the expert. The changes are similar to those that occur during adolescence – due to the hormonal surge – and in the case of pregnancy, they will help facilitate the bond between mother and child (or children). “To facilitate, not to determine, because adoptive mothers and fathers also develop this,” the neuroscientist emphasizes. This phenomenon has been known in animals for 50 years and can be caused even without pregnancy.

reversible process

Carmona clarifies that in addition to changes in size, default neural networks and attentional neural networks are affected. The first “are the regions that are activated when we do nothing,” says the expert. Simply put, when we are not doing anything, our brain is working. Think, for example, about the future, about what we are going to do next. And this network is also the key to thinking about ourselves or what others think about us. “Although it is more complex, this is what we commonly call empathy.”

Changes in this network appear to be permanent and “will likely last a lifetime.” The rest are attention networks that explain how babies manage to capture their mother’s attention. They tend to return to the state they were in before pregnancy.

Does birth type affect women’s brains in any way? “We believe that childbirth also causes changes in the brain, whether it is done vaginally or by caesarean section. It would be different if it was a planned caesarean section,” he concludes.