Sedentary Behavior Reduction in Pregnancy Intervention Study

Cardiovascular disease (CVD) accounts for 1 in 4 deaths among women of reproductive age. Decreasing adverse pregnancy outcomes (APO), e.g. hypertensive disorders of pregnancy, gestational diabetes, and preterm birth, could reduce this burden. APOs have serious immediate health consequences and are recognized by the AHA as major risk factors for future CVD. Yet, APOs are hard to prevent and treat, with a 20% prevalence that is increasing in the U.S. Moderate-vigorous intensity physical activity (MVPA) reduces APOs, but less than 1 in 4 pregnant women achieve guidelines and pregnant women report unique barriers such as fatigue, pain, medical restriction, and concern for the baby.

Sitting, or 'sedentary behavior' (SED) is a novel risk factor for CVD. Yet, sparse research and no U.S. guidelines exist for SED in pregnancy. Our recent AHA-funded cohort study in pregnant women (n=120) objectively measured SED and MVPA during each trimester. While MVPA was not related to outcomes, pregnant women with high vs. low SED across pregnancy had greater odds of APO and gave birth to babies at a reduced gestational age. Considering that decreasing SED may be more feasible given the barriers to MVPA, the investigators hypothesize that a SED reduction intervention may be especially promising for reducing APOs and improving cardiovascular health for women and their children.

Given the dearth of SED research, trials, or guidelines for pregnant women, the investigators propose to use our preliminary data on behavioral targets, correlates, and determinants of SED during pregnancy to adapt our previously successful SED reduction interventions. This pilot and feasibility study will enroll newly pregnant women with high SED and elevated APO risk (n=53) and randomize them to either a SED reduction intervention or control (2:1 ratio). Research aims include to: 1) demonstrate our ability to decrease SED and increase standing and light activity in pregnant women; 2) evaluate feasibility; and 3) gather preliminary effects on clinical outcomes including APOs, cardiometabolic risk factors, well-being, and fetal outcomes.

Participants will complete three assessment visits, one in each trimester, including 1-week monitoring of SED and activity patterns with a thigh-worn activPAL and blood pressure measurement using a standard protocol. Other outcomes will be assessed by self-report and medical record review after the participant gives birth. Participants randomized to the intervention arm will be provided with a fitbit, a sit-stand desk attachment, and will complete virtual health coaching visits every two weeks throughout pregnancy to facilitate reduced SED, increase standing, and increased stepping throughout the day.

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