Psychobiological Interventions in Pregnancy

Inclusion Criteria: * Able to read and write in English or Spanish * Presenting for a prenatal visit with a viable singleton gestation (no known lethal fetal anomaly or plan for pregnancy termination) between 18 and 20 weeks 0 days * Any history of depression or anxiety, defined as: 1) documented depression or anxiety in the medical record within the preceding 2 years; 2) baseline EPDS score \>=10 at intake prenatal visit; 3) baseline EPDS anxiety subscale 3A score \>=5 Exclusion Criteria: * Known allergy to steel or rubber * Implantable medical device * Contraindication to physical activity such as a pre-existing cardiovascular condition or arrhythmia * Plan to relocate and/or deliver at another institution * Concurrent severe mental illness (diagnosis of bipolar disorder or schizophrenia) * Known lethal fetal anomaly or nonviable pregnancy * Baseline \>30 min per week of vigorous physical activity (from Pregnancy Physical Activity Questionnaire, PPAQ)