Cortisol awakening response during risk of preterm birth and associations with anxiety
20 September 2018 (online)
PTB has a higher prevalence in psychologically strained populations. The HPA axis is being investigated as the transmitting psycho-physiological system. Studies have mostly been conducted with healthy pregnant subjects. The Cortisol Awakening Response (CAR) was assessed in women with imminent PTB (risk group/RG) and a healthy control group (CG) to analyze associations with psychological states and brith outcome.
Salivary cortisol was measured at wake-up, 30 and 45 minutes past wake-up during inpatient treatment (RG n = 34) or at home (CG n = 24). The CAR was calculated as Area Under the Curve with Respect to Increase (AUC_i). Psychological measures were obtained with questionnaires.
CAR did not differ significantly between groups (repeated measures ANOVA and t-test of AUC_i). Merely raw values of cortisol at 45 minutes past wake-up were significantly different. Within the RG anxiety was correlated with the CAR. Depression, stress and emotional exhaustion as well as covariates like BMI and parity were not correlated with the CAR. The CAR was not correlated with birth weight or GA at birth.
HPA axis reagibility is not altered during risk of PTB. In our study, dysfunctional changes of cortisol cannot explain the risk of PTB sufficiently. The positive correlation between anxiety and cortisol in patients with risk for PTB could indicate a qualitative change in HPA axis functioning above a certain threshold. Anxiety screenings should be administered during risk of PTB as enhanced anxiety levels may trigger changes in HPA axis regulation.