Effects of cognitive-behavioural therapy for stress management on stress and hair cortisol levels in pregnant women: A randomised controlled trial.

OBJECTIVE: To demonstrate the effectiveness of a cognitive behavioural therapy for stress management in pregnant women in the reduction of psychological stress and hair cortisol levels. METHODS: The trial was controlled and randomised, with a total of 78 pregnant women: control group (n-39) and Cognitive Behavioural Therapy group (n-39). To test the therapy's efficacy, an evaluation of the primary outcome (hair cortisol levels) and secondary outcomes (psychological stress, psychopathological symptomatology and resilience) was conducted before and after the treatment. The therapy was conducted during 8 sessions (one per week) in a group setting. The study was registered as a Randomised Controlled Trial with the code NCT03404141. RESULTS: The results showed a group time interaction between hair cortisol levels, psychological stress (perceived and pregnancy-specific), and in the exacerbation and severity of psychopathological symptoms. These variables presented reductions after treatment only in the Cognitive Behavioural Therapy group. CONCLUSIONS: Using a novel way of assessing chronic stress (psychological and objective measures as hair cortisol levels), this is the first study that has shown a decrease in both the levels of cortisol in hair and in psychological stress. This decline could have implications for maternal and fetal health.