Inclusion Criteria:  <13 w 0 d pregnant at risk for high levels of sedentary behavior: i) work at a desk job ≥ 30 hrs per week; ii) work at a desk job <30 hrs per week and report sitting on non-work days 1/2 the time or more; iii) do not work but report sitting 3/4 of the time or more; iv) self-reports <6000 steps per day ≥1 risk factor for APO: nulliparity, history of APO, prepregnancy BMI ≥ 30 kg/m2, or age ≥35 yr plan to deliver at UPMC facility or willing to provide medical record release for prenatal care and birth records  Exclusion Criteria:  chronic hypertension (resting blood pressure ≥140/90 mmHg or antihypertensive medication use) pre-gestational diabetes self-report of inability to walk 2 blocks or climb a flight of stairs other serious medical condition in pregnancy for which exercise is contraindicated (e.g., underlying cardiac disease, severe anemia, chronic bronchitis, or poorly controlled hyperthyroidism or seizure disorder) unable to provide physician's consent to participate participating in another health-related intervention study that could affect study outcomes