A study published last month in the journal of Nature Neuroscience used MR imaging to research the changes in the brain brought about by pregnancy. The study, entitled ‘Pregnancy leads to long-lasting changes in human brain structure’, discovered a reduction of gray matter regions pertaining to social cognition in the brains of pregnant women.

The research was conducted in Spain, and scanned the brains of 25 first-time mothers before and after giving birth, and then again two years later. For a control group, the researchers also scanned 17 men and 20 women without children. The structural changes in the brains of the pregnant women were so constant that the researchers were easily able to separate the research subjects from the control group, using only the brain images.

Consistently, the researchers observed something called “gray matter pruning”, a phenomenon in which unnecessary neural connections already formed in the gray matter are left to shrink and fade away in order to make room for new, more specialized neural connections and attachments. “The gray matter volume changes of pregnancy significantly predicted the quality of mother-to-infant attachment and the absence of hostility towards their newborns in the postpartum period,” wrote the authors of the study. Furthermore, this preliminary research showed these changes in brain structure can last up to two years or longer.