New moms often complain about fuzzy thinking during pregnancy, but a recent study shows that pregnancy may cause lasting changes in women's brains that won't affect their memories but rather help their transition into motherhood.
"On the basis of our results, we may speculate that the female brain undergoes a further maturation or specialization of the neural network subserving social cognition during pregnancy," said the study published in the journal Nature Neuroscience on Monday.
The study took more than five years and involved 25 women in their 30s in Spain who had never been pregnant before.
Using magnetic resonance imaging, scientists scanned the brains of women before and after their first pregnancies and found reductions of gray matter in several brain areas involved in a process called social cognition, the ability to register and consider how other people perceive things.
The brain changes, which lasted for at least two years after the women gave birth, probably help them adapt to motherhood, the study suggested.
In order to find if the women's brain changes affected anything related to mothering, researchers found that relevant brain regions in mothers showed more activity when women looked at photos of their own babies than at photos of other children.
"The changes concern brain areas associated with functions necessary to manage the challenges of motherhood," study co-lead author Erika Barba-Muller said.
"Gray matter volume loss does not necessarily represent a bad thing. It can also represent a beneficial process of maturation or specialization," said Elseline Hoekzema, a researcher who led the study at the Universitat Autonoma de Barcelona in Spain.
Pregnancy may help a woman's brain specialize in "a mother's ability to recognize the needs of her infant, to recognize social threats or to promote mother-infant bonding," Hoekzema said.
The changes "may reflect, at least in part, a mechanism of synaptic pruning ... where weak synapses are eliminated giving way to more efficient and specialized neural networks," she added.