Neural emotion regulation during pregnancy - a fMRI study investigating a transdiagnostic mental health factor in healthy first-time pregnant women

Pregnancy is a psycho-neuro-endocrinological transition phase in which a plethora of hormone levels rise substantially, modulating socioemotional functions, brain structures, and networks and thus presenting a window of vulnerability for mental health. A transdiagnostic factor for psychopathology is emotion regulation, which is influenced by sex hormones, such as estradiol (E2), across the menstrual cycle on the behavioral and neural level. Whether this is also the case in the antepartum period remains unknown. For the first time, behavioral and neural emotion regulation were investigated in healthy primiparous pregnant females with extremely high E2 levels during the second trimester (N = 15) using a functional magnetic resonance imaging (fMRI) paradigm. Results were compared with naturally-cycling females with high E2 levels (after E2-administration, N = 16) and low E2 levels (early follicular phase, N = 16). Although pregnant females reported the lowest trait use of cognitive reappraisal, all females successfully regulated their emotions by applying cognitive reappraisal in the scanner. On the neural level, all females had increased activity in the left middle frontal gyrus during downregulation of negative emotions. Pregnant females showed no significant differences in functional connectivity (psychophysiological interaction, resting-state) related to emotion regulation compared to the nonpregnant group. However, group differences emerged for amygdala activation. In pregnant females, increased amygdala activity predicted reduced regulation success and was positively associated with depression scores. This first fMRI study during pregnancy indicates that depression scores are reflected in heightened amygdala activity already observable in the antepartum period. Thus, through its association with reduced regulation success, increased amygdala activity suggests a neural risk marker for peripartum mental health. Future research needs to investigate emotion regulation in pregnant and postpartum women to further understand pregnancy-related changes and associations of mood, emotional and neural functions. Eventually, this will allow enhanced identification, prevention, and treatment of peri- and postpartum mental ill-health.