The cerebral changes induced by paternity in humans have been studied very little, in comparison with research projects done with animal models. In mammals, a constellation of microscopic and macroscopic changes at functional and structural levels have been proven that are associated with pregnancy and exposure to newborns. Mammals’ brains change during pregnancy and these changes continue during the child-raising period. Our main objective is to clarify the cerebral changes associated with pregnancy and the breastfeeding period in humans. To do so, neuroimaging techniques will be applied for the first time to identify both the structural and functional changes of mothers’ and fathers’ brains during pregnancy and during the first six months of child raising. Functional and structural magnetic resonance methods shall be employed at three times: before pregnancy, during the post-birth period and after six months. A control group will be used that is comparable to the mothers and fathers and the results will be correlated using hormonal measurements and a battery of psychometric tests.