Use of Hair Cortisol as a Biomarker for Chronic Stress in Pregnancy

In a pilot study from 2005, researchers investigated the use of hair cortisol levels as a biomarker for chronic stress in pregnant women. They enrolled 50 women, divided into two groups: 25 who were pregnant and depressed, and 25 who were pregnant and not depressed. Participants provided hair samples and completed questionnaires to assess depression and chronic stress levels. The study found a strong correlation between chronic stress and depressive symptoms across all participants (rs=0.86, p<0.000001). Interestingly, in the depressed group, higher levels of stress and depression were associated with lower levels of hair cortisol (rs=−0.40, p<0.05 for stress; rs=−0.39, p<0.05 for depression). Conversely, in the non-depressed group, chronic stress was positively correlated with hair cortisol levels (rs=0.36; p<0.05). These results suggest that hair cortisol may be a viable biomarker for chronic stress in pregnancy, but also indicate that depression may influence cortisol levels differently than stress alone.