A mom's brain grows after birth

A mom’s brain grows after birth

21 March 2011 No Comments

By Debra Black

A mother’s brain grows during the first few months after she’s given birth, according to a recent study published in the October issue of Behavioural Neuroscience.

A team of Yale researchers led by Pilyoung Kim, a neuroscientist who is now at the National Institute of Mental Health, studied the brains of 19 mothers just after they had given birth and then three to four months post-partum.

The mothers, who were on average just over 33 years old and had 18 years of schooling, had two MRIs on their brains taken during that period.

Their children were born at Yale-New Haven Hospital. Ten of the mothers had boys, nine had girls. None of them suffered from serious post-partum depression. All were breast-feeding and almost half had other children.

The team compared the two sets of MRIs and found a “small but significant increase in gray-matter volume in part of the brain over the first few months of motherhood,” said Kim in an interview with the Star.

Previous studies of animals, particularly rodents, have also shown that the maternal brain goes through structural changes after the baby’s birth, Kim said.

According to the study, the mothers who reported their babies as special, beautiful, ideal and perfect developed bigger mid-brains than less enthusiastic mothers did.

The changes in the mothers in Kim’s study take place mostly in the mid-brain region, which the neuroscientist says plays an important role in maternal motivation and processing reward information.

Other areas of the mothers’ brains were also affected, including:

• the prefrontal cortex, which is responsible for high-level cognition such as monitoring one’s behaviour, learning new skills and planning;

• and the parietal cortex, which is important for processing sensory information from the environment such as a baby’s smiles or cries.

“The first few months of motherhood are especially stressful,” Kim said. “But at the same time, our study suggests the mother’s brain goes through changes so the mothers can focus their energy on their own infants and find more positive meanings in their experience and in turn develop emotional connections with their infants.”

The study leads to interesting questions about the mother-child relationship, Kim said. The changes in the mothers’ brains may be related to the stimuli they receive from their interaction with their infants, she added.

In turn, that stimuli may help “orchestrate a new, increased repertoire of complex interactive behaviours with the infants,” the study said. Those behaviours may result in more nurturing, and may help babies thrive.

Kim and her fellow researchers plan to follow up with more studies, including mothers who are depressed and or have trouble bonding with their babies.

They also have studied the brains of new fathers to see what changes, if any, occur in their brains.

Originally published on parentcentral.ca March 21st, 2011.