Mid-pregnancy allopregnanolone levels and trajectories of perinatal depressive symptoms.

Perinatal depression is a major cause of disability for individuals giving birth worldwide, with detrimental effects on short- and long-term parental and child outcomes. There is emerging evidence that the neuroactive steroid hormone allopregnanolone is implicated in the pathophysiology and course of perinatal mood symptoms. However, no study thus far has examined allopregnanolone levels whilst making use of longitudinal data on depressive symptom trajectories throughout the perinatal period. The present study investigated levels of allopregnanolone at gestational week 17 of 252 participants in relation to perinatal depressive symptom trajectories, with a secondary aim of exploring the role of history of depression as an effect modifier. Four perinatal depressive symptom trajectories were investigated: controls (no depressive symptoms throughout perinatal period) (N=161), antepartum (depressive symptoms prenatally with postpartum remission) (N=31), postpartum-onset (no depressive symptoms during pregnancy, development of depressive symptoms postpartum) (N=23), and persistent (depressive symptoms throughout the perinatal period) (N=37). Results show that for every one nmol/l increase in allopregnanolone, there was 7% higher odds for persistent depressive symptoms (OR 1.07, 95% CI 1.01-1.14) compared to controls. No association was seen for antepartum and postpartum-onset depressive symptoms. History of depression did not modify the association between allopregnanolone and perinatal depressive symptom trajectories. These results show the role of allopregnanolone for persistent depressive symptoms and strengthen the hypothesis of differences in pathophysiology among the trajectories.