Associations between maternal psychological distress and salivary cortisol during pregnancy: A mixed-models approach.

Background: Maternal psychological distress during pregnancy is related to adverse child behavioral and emotional outcomes later in life, such as ADHD and anxiety/depression. The underlying mechanisms for this, however, are still largely unknown. The hypothalamic-pituitary-adrenal (HPA)-axis, with its most important effector hormone cortisol, has been proposed as a mechanism, but results have been inconsistent. The current study investigated the association between maternal psychological distress (i.e. anxiety and depressive symptoms) and maternal cortisol levels during pregnancy using a mixed models approach.

Method: During three pregnancy trimesters, mothers (N = 170) collected four salivary samples for two consecutive days. Mothers reported symptoms of anxiety and depression three times during pregnancy (at 13.3 ± 1.1, 20.2 ± 1.5, and 33.8 ± 1.5 weeks of pregnancy, respectively) using the anxiety subscale of the Symptom Checklist (SCL-90), the Spielberger State and Trait Anxiety Inventory (STAI), and the Edinburgh Postnatal Depression Scale (EPDS). Specific fears and worries during pregnancy were measured with the short version of the Pregnancy Related Anxiety Questionnaire (PRAQ-R).

Results: We found a significant effect of SCL-90 anxiety subscale on cortisol levels at awakening (p = .008), indicating that mothers with higher anxiety showed lower cortisol at awakening. Maternal psychological variables explained 10.5% of the variance at the person level in awakening cortisol level, but none in the overall diurnal cortisol model.

Conclusion: More research is necessary to unravel the underlying mechanisms of the association between maternal psychological distress and cortisol and the search for mechanisms other than the HPA-axis should be continued and extended.