Neuroscientist Liz Chrastil got the unique chance to see how her brain changed while she was pregnant and share what she learned in a new study that offers the first detailed map of a woman's brain throughout gestation. The transition to motherhood, researchers discovered, affects nearly every part of the brain. Although the study looks at only one person, it kicks off a large, international research project that aims to scan the brains of hundreds of women and could one day provide clues about disorders like postpartum depression.

“It’s been a very long journey,” said Chrastil, co-author of the paper published Monday in Nature Neuroscience. “We did 26 scans before, during and after pregnancy” and found “some really remarkable things.” ALSO READ: Are you pregnant? 8 simple things you can do to have an intelligent baby More than 80% of the regions studied had reductions in the volume of gray matter, where thinking takes place.

This is an average of about 4% of the brain — nearly identical to a reduction that happens during puberty. While less gray matter may sound bad, researchers said it probably isn't; it likely reflects the fine-tuning of networks of interconnected nerve cells called “neural circuits" to prepare for a new phase of life. The team began following Chrastil — who works at the University of California, Irvine, and was 38 years old at the time — shortly before she became pregnant through in vitro fertilization.

During the pregnancy and for t.