During the course of this project, an extensive prospective cohort dataset will be collected in which women who want to become pregnant are investigated and followed throughout this trajectory. At the moment, we have completed the majority of the pre-pregnancy sessions and are continuously investigating women during their pregnancies and have just started with the postpartum follow-up sessions. The first 1-year postpartum follow-up sessions are planned this autumn. In addition, neuroimaging analyses of a dataset we have already collected have rendered various new insights. For instance, we have shown that pregnancy leads to selective and robust changes in brain architecture and neural network organization. These changes related to pregnancy hormones, especially third-trimester estradiol. Furthermore, the observed brain changes were associated with maternal processes such as nesting behavior, maternal-fetal bonding and the physiological responsiveness to infant cues. We also found that these changes predicted measures of mother-infant bonding and impairments in this bonding process. Analyses of the hypothalamus, a central structure of the mammalian maternal brain that is known to play a key role in the induction of maternal behavior in non-human mammals, revealed that becoming a mother is associated with anatomical changes in various substructures of this brain area. These changes related to hormone levels during pregnancy and to specific aspects of maternal behavior such as nesting behavior and maternal-fetal attachment. Together, these findings indicate that pregnancy is associated with hormone-driven changes in brain structure and function in humans and suggest that, similar to other mammals, these changes relate to the development of maternal behavior.
