a study released monday , dec. 19 , 2016 shows pregnancy group .
for this prospective cohort study , first - time mothers participated in an mri acquisition before and after their pregnancy , allowing us to use each woman 's pre - pregnancy brain scan as her individual baseline .
the study includes data on 25 spanish women scanned before and after their first pregnancies , along with 20 women who did n't get pregnant during the study .
only participants who had never experienced a previous pregnancy beyond the first trimester were included in the study .
recruitment and data collection for all groups was initiated at the same time .
for example , they might help a mother understand the needs of her infant , elseline hoekzema , a study author at leiden university in the netherlands , explained via email .
they also found hints that the alterations help women prepare for motherhood .
although individuals were recruited separately for the pregnancy ( prg ) groups ( women and men becoming parents between the sessions , hereafter referred to as f prg and m prg , respectively ) and the control ( ctr ) groups ( women who did not become pregnant within this time frame and men whose partners did not become pregnant , from here on referred to as f ctr and m ctr ) on the basis of their intention to become parents in the near future , the final group allocation depended on the transition from nulliparity into primiparity in between sessions .