Background: Immune activation has been shown to be involved in the pathophysiology of anxiety states and major depression and pregnancy is associated with a characteristic immune activation to sustain the fetus. Despite the possibility of a relation between immune parameters and postpartum mood disturbance, few studies have explored this association. Further, no study to-date has examined CSF.
Methods: Fifty-six Greek parturients were recruited and a detailed medical and obstetric history was recorded. All of them completed the Postpartum Blues Questionnaire (on admission and on days 1-4 postpartum) and the Edinburgh Postnatal Depression Scale (at first and sixth week postpartum). At delivery, a blood sample and a CSF sample while puncturing for epidural analgesia were taken from 33 participants; blood samples only were obtained from the rest of the 23 parturients. TNF-a and IL-6 were quantified with an ELISA assay.
Results: A multiple regression analysis of psychometric scores depending on cytokine levels revealed that cytokine levels were positively associated with depressive mood during the first four days postpartum (p=0.035 for CSF IL-6, p=0.025 for CSF TnF-a, p=0.023 for serum TnF-a) and also at sixth week postpartum (p=0.012 for CSF IL-6, p=0.072 for CSF TnF-a). Pregnancy duration had an adverse association to psychometric scores.
Conclusions: It is suggested that immune mechanisms may play a role in the etiopathology of postpartum depressive mood shifts. The role of a "rebound" reaction of the maternal immune system postnatal should be further investigated.