‘brain mom’ doesn’t capture how the brain changes during pregnancy

Pregnancy shrinks parts of the brain. That sounds bad. Forgetfulness and fogginess, or “momnesia,” many moms report, and the idea that the brain is left behind is a net loss in the transition to motherhood.

“I see it on social media all the time,” says neuroscientist and therapist Jodi Pawluski of the University of Rennes in France. “It escapes your brain. That’s why [you] let him forget everything. “

But this is not true, says Pawluski. The perception that the maternal brain is dysfunctional has come a long way: It’s time to “start giving the maternal brain the credit it deserves,” Pawluski and her colleagues write in February. JAMA Neurology.

Pregnancy causes structural changes to kick in the brain, including the loss of gray matter. But the loss isn’t necessarily bad—reductions may reflect subtle processes that make the brain more efficient (SN: 3/18/22).

During the transition to motherhood, the brain organizes its connections, strengthening the ones that are useful and letting go of those that aren’t, Pawluski says. This organization prepares the brain “to learn quickly to keep the baby alive,” he says.

In a 2016 study, for example, researchers reported brain changes, including reductions, that appear to favor a new baby (SN: 12/19/16). Another work by this team found pregnancy depression in the ventral striatum, a region involved in movement and reward. Those reductions in the mothers’ brains were associated with increased responsiveness to their babies, the team reported in Psychoneuroendocrinology in 2020

However, many pregnant and postpartum women report memory loss. Studies don’t find significant differences when comparing memory tests for new mothers with non-mothers, Pawluski says, but more research is needed to understand the mental burden of parenthood — the impact of endless responsibilities and distractions.

A possible explanation for “momnesia” or “mommy brain” is that new mothers turn their attention to the baby and turn it away from other things. Pregnant women, as opposed to never-pregnant women, showed a boost in learning about baby-related objects compared to adult-related objects, researchers reported in Memory in 2022. Pregnant women were also better able to recall relationships between things and places.

The changes in the maternal brain are similar to those seen in adolescence. A study of first-time mothers and adolescent females found reductions in maternal brain volume compared to those seen in adolescence, researchers reported in Human Brain Mapping in 2019. “We think of adolescence as a time of transition and a lot of neuroplasticity,” or the brain’s ability to change, Pawluski says. The transition to motherhood is like an impact on the brain, she says.

Crediting the maternal brain for its incredible adaptations does not mean that anxiety is an expertise exclusive to those who give birth. While hormones trigger brain modifications during pregnancy, the brain does not change with the experience of giving birth. After the birth of their first child, the new fathers’ brains showed a reduction in gray matter, but the brains of men without children did not, the researchers reported. Cerebral cortex in 2012

Mistakes around the brain during the transition to motherhood “goes back to recognizing the importance of care,” says Pawluski from all parents. “The ability of your brain to learn to live as a baby is a big deal to keep.”