Psychosocial factors, including a previous history of depression, recent stressful life events, sleep disturbances during pregnancy, and depression and/or anxiety during pregnancy have been shown to be associated with an increased risk for the development of postpartum depression (PPD). Biological mechanisms underlying the relationships among these psychosocial risk factors for PPD, and the development of PPD, remain unclear. However, evidence from non-perinatal populations suggest that dysregulation in stress-reactive neuroendocrine factors may play a role. The primary objectives of this study are: (1) to assess the feasibility of enrolling second trimester pregnant women, with or without depression histories, into a laboratory-based study protocol which includes a mild psychosocial stressor and the collection of venous blood for the measurement of stress-reactive adrenocorticotropic hormone (ACTH) and cortisol; (2) to assess the feasibility of retaining participants, for a brief postpartum phone interview, after completion of the second trimester assessments; and (3) to establish proof of concept for measuring group differences, between women with or without depression histories, in second trimester prenatal measures of neuroendocrine stress reactivity, depressive and anxious symptoms, recent stressful life events, and sleep quality.