Within-Person Changes of Cortisol, Dehydroepiandrosterone, Testosterone, Estradiol, and Progesterone in Hair Across Pregnancy, with Comparison to a Non-Pregnant Reference Group

The study investigated changes in cortisol, dehydroepiandrosterone (DHEA), testosterone, estradiol, and progesterone in hair across pregnancy, comparing pregnant women to a non-pregnant control group. It found that progesterone levels significantly increased in pregnant women, while DHEA levels decreased early in pregnancy. There was suggestive evidence of increases in cortisol and estradiol during pregnancy, but these changes were not significantly different from those in non-pregnant women. Testosterone levels showed little change. The study highlighted substantial individual variability in hormone changes and emphasized the importance of considering within-person trajectories and non-linear patterns in future research. Hair was noted as a useful biospecimen for capturing cumulative hormone levels over time, despite limitations such as small sample size and batch effects.