Many women will be happy to find out the brain actually grows after childbirth, according to a new study published by the American Psychological Association. The areas of motivation, behavior and mid-brain are most strongly affected.

Brain growth after child birth may be linked to increases in estrogen, oxytocin and prolactin levels. Researchers believe the brain prepares for motherhood by growing the parts of the brain most used by new mothers. If this research is correct, it could lead to further studies involving women with the “natural instinct” and those who do not.

Nineteen women were included in the study. About half gave birth to girls and the other half boys, so gender does not come into play. Brain scans were taken two to four weeks after childbirth and again at the three to four month mark. Significant changes in brain mass were noted in the hypothalamus, substantia nigra, amygdale, parietal lobe and prefrontal cortex.

Mothers who fawned over their newborn babies more often and with greater passion tended to show more brain growth when compared to peers in the group with less passionate feelings. All mothers were around 33 years of age and had completed 18 years of schooling. All mothers also breastfed their newborns. No cases of serious post partum depression were noted in the participant group.

If post partum depress is an issue, the areas of the brain growth may not be as substantial or noted at all. Depression causes shrinking of the same areas of the brain that grow with motherly passion.

Source: Pilyoung Kim, PhD, Cornell University and Yale University School of Medicine; James F. Leckman, MD, Yale University School of Medicine; Linda C. Mayes, MD, Yale University School of Medicine and The Anna Freud Centre; Ruth Feldman, PhD, Yale University School of Medicine and Bar-Ilan University; Xin Wang, MD, PhD, University of Michigan, James E. Swain, MD, PhD, FRCPS, Yale University School of Medicine and University of Michigan. Behavioral Neuroscience. 21 October, 2010.