Pregnancy affects women's brains for years after birth
Pregnancy changes a woman's brain for at least two years, new research shows.
When researchers compared brain scans of women before and after pregnancy, they spotted some differences in 11 locations. They also found hints that the alterations help women prepare for motherhood.
For example, they might help a mother understand the needs of her infant, according to Elseline Hoekzema, one of the authors of the Dutch/Spanish study.
The research is founded on 25 Spanish women scanned before and after their first pregnancies, along with 20 women who didn't get pregnant during the study.
The results were consistent: A computer program could tell which women were pregnant just from the results of the MRI scans. The changes, first documented an average of 10 weeks after giving birth, were mostly still present two years after childbirth. That's based on a follow-up with 11 study participants. The effects were exclusive to mums - no changes were seen in first-time fathers.
Despite a common belief that new mums become more forgetful, the women showed no declines on tests of memory.
Based on prior research findings, the researchers believe the brain changes happened during pregnancy rather than after childbirth.
Hoekzema and her colleagues at the Autonomous University of Barcelona think the differences result from sex hormones that flood the brain of a pregnant woman.
In the 11 places, the MRI data indicate reductions in volume of the brain's grey matter, but it's not clear what that means. For example, it could reflect loss of brain cells or a pruning of the places where brain cells communicate, called synapses.
Losing some synapses is not necessarily a bad thing for people.
It happens during a hormonal surge in adolescence, producing more specialised and efficient brain circuits.
The researchers suspect that could also be happening in the pregnant women.