For the first time, deep changes in the brain during pregnancy have been scientifically confirmed!

During pregnancy, the human body undergoes profound physiological changes, and the brain is no exception.

Neuroscientists from the United States presented the first detailed map of the human brain throughout pregnancy.

The breakthrough is based on neurological changes in one mother who became a mother for the first time. She had brain images before, during and after pregnancy.

As the pregnancy progressed, the researchers noticed a widespread contraction of the gray matter - the brain tissue that includes the bodies of neurons.

Although the contraction of parts of the brain may seem frightening, these changes are probably for the better. They can reflect the reconfiguration of the final brain tissue for motherhood.

The researchers found that the connections between the neurons that make up the white matter intensified in the last two trimesters of pregnancy.

When neural circuits are rebuilt for any reason, the number of connections in the gray matter usually decreases, and the number of connections in the white matter increases, which allows information to be transmitted more efficiently through the brain.

Neurobiologist Emily Jacobs from the University of California, Santa Barbara, compares this process to how Michelangelo chops a piece from David's carving. The artist starts with a large piece of marble, she explains, but through careful grinding he turns into an exquisite work of art.

"We have never seen the brain undergo such metamorphoses," Jacobs said at a press conference.

"We were able to observe radical changes in the volume of gray matter, the thickness of the cortex, the microstructure of the white matter and the volume of the ventricles, as all this happened week after week."

Not so long ago, neuroscientists believed that the human brain was "rigidly programmed" with fixed chains of neurons. Now we know better. The brain actually has a soft structure, that is, it is plastic and pliable, undergoing significant changes as we learn and age.

The idea of plasticity caused a sensation in the field of neuroscience, and now another revolution is looming on the horizon.

To date, only 2 percent of neuroimaging studies mention sex hormones as influencing factors, although few published papers suggest a statistically significant relationship between sex steroids and changes in the brain.

For example, in 2024, researchers documented in detail the structural changes that occur in the brain when hormonal changes during menstruation.

However, according to neurobiologist Elizabeth Krastil from the University of California at Irvine, there are only a few studies on what happens to the brain during pregnancy.

In 2017, researchers showed that pregnancy is accompanied by a significant reduction in gray matter, and in 2022, a subsequent study involving 28 volunteers showed that pregnancy hormones change the way brain neural networks are organized.

"We still don't understand a lot about pregnancy neurobiology, and it's not because women are too complicated, and not because pregnancy is some kind of Gordian knot," Jacobs says.

This is a by-product of the fact that biomedical sciences have historically ignored women's health. It's 2024, and this is the first glimpse of this exciting neurobiological transition."

A new MRI study was conducted on a 38-year-old woman who had no previous children and who underwent in vitro fertilization (IVF) to achieve pregnancy.

The participant underwent a total of 26 MRI scans, including four scans three weeks before conception, several scans in the first, second and third trimester and seven scans within two years after childbirth. The researchers also took blood samples from the participant throughout this period of time.