What happens to a woman's brain when she becomes a mother

Oxytocin also increases as women look at their babies, or hear their babies’ coos and cries, or snuggle with their babies. An increase in oxytocin during breastfeeding may help explain why researchers have found that breastfeeding mothers are more sensitive to the sound of their babies’ cries than non-breastfeeding mothers. “Breastfeeding mothers show a greater level of [brain] responses to baby’s cry compared with formula-feeding others in the first month postpartum,” Kim said. “It’s just really interesting. We don’t know if it’s the act of breastfeeding or the oxytocin or any other factor.”

What scientists do know, Feldman says, is that becoming a parent looks—at least in the brain—a lot like falling in love. Which helps explain how many new parents describe feeling when they meet their newborns. At the brain level, the networks that become especially sensitized are those that involve vigilance and social salience—the amygdala—as well as dopamine networks that incentivize prioritizing the infant. “In our research, we find that periods of social bonding involve change in the same ‘affiliative’ circuits,” Feldman said. “We showed that during the first months of ‘falling in love’ some similar changes occur between romantic partners.” Incidentally, that same circuitry is what makes babies smell so good to their mothers, researchers found in a 2013 study.

The greatest brain changes occur with a mother’s first child, though it’s not clear whether a mother’s brain ever goes back to what it was like before childbirth, several neurologists told me. And yet brain changes aren’t limited to new moms.

Men show similar brain changes when they’re deeply involved in caregiving.