This is why some pregnant women may experience small, sometimes subtle deficits in tasks, like recalling items from a list they have studied, or remembering to do certain things in the future.

After delivering the baby, it would take up to six months for the mother's brain to regain its original size. The cells in the brain reduce in size without reducing in number. In other words, neuron density remains the same, which is why the brain capacity returns to normal after childbirth.

A study published in Nature Neuroscience revealed that pregnant women experience a decrease in gray matter in specific brain regions responsible for social cognition and forming attachments. However, this loss of gray matter actually enhances a mother's feelings of attachment to her baby and improves her ability to understand their needs and emotions.

Using MRI scans, researchers examined the brains of pregnant women before and after giving birth. They discovered that the reduction in gray matter in specific brain regions actually improves the brain's efficiency in understanding nonverbal cues from newborns.

This change enables mothers to quickly identify potential dangers and enhances their emotional connection with their babies. The first study was published in the American Journal of Neuroradiology, and it’s entitled, “Change in brain size during and after pregnancy: study in healthy women and women with preeclampsia”. The second study was published in Nature Neuroscience and it’s entitled, “Pregnancy leads to long-lasting changes in human brain structure”