Nesting, baby showers, and those sweet ultrasound pics might seem like the most exciting, dynamic way to prepare for the birth of your sweet little one. But internally, your brain is making massive and exciting changes, too, as a way to support your new role as a mom.

The truth is, preparing oneself to give birth and for the new demands of motherhood requires an entirely new set of skills, cognitions, and capabilities, and a woman’s brain makes enormous shifts during pregnancy and after birth in order to tackle the demands of the new responsibilities.

The maternal brain circuitry—or the parts of the brain that are specifically used for the tasks associated with mothering—demonstrate increased brain activity and changes in structure and size during pregnancy and in the weeks and months following birth.

We’ve only recently started actually studying the exact nature of these changes in a mom’s brain. The prevailing data over the past few years has shown that some parts of the brain increase in size throughout pregnancy and postpartum, which is perhaps expected given a mother’s many new cognitive demands. However, a recent study using brain scans has shown a surprising and seemingly counterintuitive result: that some areas of gray matter in the brain actually shrink postpartum.

On the list of brain changes that occur are large hormonal shifts involving oxytocin and progesterone. These hormone fluctuations are essential in the bonding between a mother and baby. For example, a baby’s laughter or cries result in higher levels of maternal oxytocin. Some areas of your brain, such as the amygdala and the reward pathway, also see extraordinary increases in activity during pregnancy and postpartum. The amygdala—a brain structure that is tasked with memories and emotions like fear and anxiety—becomes very active, which could have had the evolutionary benefit of making moms more sensitive to their baby’s needs and emotions.

Another significant change has to do with the brain’s reward pathway, a series of brain structures that communicate through the usage of the “feel-good” chemical dopamine. This pathway, which tends to activate when there’s a pleasurable stimulus, is a key player in new mom brain changes, lighting up favorably whether the baby is crying or laughing. This is particularly important in maintaining a close bond between the two and maintaining a mom’s motivation to consistently care for her baby’s needs. Because as any mom knows, it’s a lot of work!