Statistical analysis
Statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS version 26, IBM Inc., Armonk, NY, USA). The original HCC values were both divided into quintiles and also transformed into logarithm values. The associations between sociodemographic variables and parity as well as use of medications were tested by Pearson’s chi2-test. The medians of the original values were used as measures of central tendency and variation, respectively. Due to the non-normal distribution of the original HCC values, Spearman’s correlation coefficient was used when determining whether cortisol levels were correlated with possible confounding variables. Multivariate linear regression analyses were based on logarithm-transformed values and were made to assess possible associations among the nine HCC measurements for each participant. A p-value p < 0.05 (two-sided) was considered statistically significant.