Does Becoming a Mom Increase Brain Size?

Becoming a mom has its benefits - but can it even make you smarter? According to a new study published in Behavioral Neuroscience, having a child could give you a bigger brain.

Does Becoming a Mom Increase Brain Size?

Researchers from the National Institute of Mental Health did MRI imaging of 19 women after they gave birth - and repeated it at three weeks and three months. The findings were surprising. These women who had just delivered had a small, but significant, increase in the amount of gray matter in their brain. Gray matter is made up mostly of nerve cell bodies and is the portion of the brain most strongly associated with information processing and intelligence. In fact, the amount of gray matter is more important than overall brain size for determining intelligence.

Even more interesting was the observation that moms who were most enthusiastic about being a mom had the greatest increase in gray matter - compared to mothers who were less enthused about their new status as "mommy".

Why Does Becoming a Mom Increase Brain Size?

Keep in mind this increase in gray matter researchers wasnt huge - but it was still significant. One explanation is that areas of the brain involved in motivation and nurturing expand to allow new moms to interact and better care for a new baby. If this is true, it shows how adaptable the human brain really is. Whats the stimulus that causes brain gray matter to grow? It may be higher levels of hormones such as estrogen, progesterone, and oxytocin that moms have circulating in their bloodstream after birth.

Oxytocin, a hormone associated with feelings of love and nurturing, is important, and its levels increase greatly at the time of delivery. Not only does it help with uterine contractions during labor, it plays a role in maternal nurturing behavior. Rats that receive injections of drugs that block oxytocin dont behave like a good mommy toward their offspring after birth.

Gray Matter and Becoming a Mom

Larger studies are needed to confirm that becoming a mom really increases brain size, but it does show that mothering is a complex activity that requires lots of gray matter. Doesnt it make you appreciate your mom all that much more?

References:

Eurekalert.org. "he Real ?Mommy Brain: New Mothers Grew Bigger Brains Within Months of Giving Birth"
The Journal of Endocrinology 112 (2): 275"82.