Increased morning adrenocorticotrophin hormone (ACTH) levels in women with postpartum thoughts of harming the infant.

INTRODUCTION

Some postpartum women experience intrusive thoughts of harming the infant. The hypothalamic-pituitary-adrenal (HPA) axis, which has been linked to postpartum depression, may play a role in the aetiology of postpartum thoughts of harming the infant. We aimed to study whether HPA axis hormones measured early postpartum are related to postpartum intrusive thoughts.

METHOD: 132 women who delivered a child at a university hospital participated in a follow-up study with visits at 2-3 days postpartum and 8th week postpartum. Participants were assessed for trait anxiety, social support, peripartum or postpartum anxiety or depression, stressful life events and obstetric variables including perinatal complications and lactation. Postpartum thoughts of harming the infant were assessed with a semi-structured interview. Serum cortisol, and plasma CRH and ACTH levels were measured within 48 h postpartum at 8-9 AM. A logistic regression was performed to explore the relationship between clinical variables, hormonal measures and postpartum intrusive thoughts.

RESULTS

Patients with postpartum thoughts of harming the infant had, when compared to those women without intrusive thoughts, higher ACTH levels (7.59 pmol/L vs 5.09 pmol/L, p<0.05) without significant differences in CRH or cortisol levels. In the logistic regression analysis, adjusted for breast-feeding and psychopathological status, only ln ACTH was associated with the presence of postpartum thoughts of harming the infant (OR=5.2, CI 95% 1.2-22.6, p=0.029). No other clinical variables were associated with postpartum intrusive thoughts.

CONCLUSIONS

Our study suggests that a dysregulation of the hypothalamic-pituitary-adrenal axis may play a role in the aetiology of postpartum thoughts of harming the infant.