Pregnancy changes women’s brains for at least two years, according to a new study from the Universitat Autònoma de Barcelona and Leiden University published in Nature Neuroscience. But unlike “pregnancy brain,” which some women say causes forgetfulness, this change in the brain helps prepare women for motherhood.
Researchers found that pregnancy reduces gray matter in certain areas of the brain, helping the woman bond with her new baby and prepare for motherhood. These changes can last for up to two years.
The scale of brain changes during pregnancy were similar to those changes seen during adolescence, the study stated.
“These changes concern brain areas associated with functions necessary to manage the challenges of motherhood,” Erika Barba, the study’s co-lead author said in a statement.
Using MRI scans, the researchers compared the structure of women’s brains before and after their first pregnancy. The scans showed a significant difference in gray matter in areas of the brain associated with social interactions used for attributing thoughts and feelings to other people, also known as “theory-of-mind” tasks.
This occurrence in certain areas of the brain is believed to help expecting mothers recognize the need of their children, be more aware of possible social threats and bond more with their baby.
“The findings point to an adaptive process related to the benefits of better detecting the needs of the child, such as identifying the newborn’s emotional state,” Oscar Vilarroya, the study’s research director said. “Moreover, they provide primary clues regarding the neural basis of motherhood, perinatal mental health and brain plasticity in general.”
Just by analyzing the MRI scans, computers were able to determine which women had been pregnant.
Researchers showed women pictures of their own babies and other babies while monitoring their brain activity. When the women in the study saw images of their own children, the parts of their brain where the gray matter was reduced during pregnancy lit up. The same areas did not light up when the women were shown pictures of other babies.
“We can speculate that the volume reductions observed in pregnancy represent a process of specialization or further maturation of this Theory of Mind network that, in some way, serves an adaptive purpose for pending motherhood,” said Elseline Hoekzema, study author and postdoctoral researcher at the Institute of Psychology at Leiden University in the Netherlands.
The study found that all pregnant women were affected in similar ways, no matter if they conceived naturally or through IVF. The researchers also discovered no change in gray matter for first-time fathers when they were monitored before and after their partner’s pregnancy.