To investigate the effect of sociospatial inequality on exposure to stress, symptoms of depression, and cortisol rhythms during pregnancy.

Secondary analysis of a cross-sectional observational study.

Outpatient women’s health clinic in an urban midwestern region of the United States.

Pregnant women in the second trimester of pregnancy (N = 67).

We performed a secondary analysis of salivary cortisol samples to compute average daily cortisol rhythms (diurnal slope, area under the curve, mesor, amplitude, and acrophase). We measured sociospatial inequality using the index of concentration at the extremes based on zip-code-level data from the American Community Survey. We used mixed-effects cosinor regression to examine the association among sociospatial inequality, exposure to stress, symptoms of depression, and cortisol rhythms, adjusting for multiple covariates.

Sociospatial inequality was significantly associated with demographic variables (age, race, and education) and mental health variables (exposure to stress and symptoms of depression). We found a statistically significant curvilinear association between income-related sociospatial inequality and cortisol rhythms.

Participants who lived in areas of extreme income-related deprivation and privilege had higher amplitude cortisol rhythms, which potentially reflects heightened biological sensitivity to context, whereas women living in more moderate environments showed buffered cortisol rhythms.