Pregnancy blood pressure tracked sitting time. Workouts showed no clear link.
People say: “Does sitting time matter in pregnancy?” We read the study.
Cohort study. 470 people. 7 days of 24-hour monitor wear in each trimester (about weeks 10-12.6, 20-22.6 and 32-34.6), outcome from medical records through delivery; enrolled 2021-2024.
People were watched for years. Nobody was told what to do. A clue, not proof.
Who: 470 pregnant participants (of 500 enrolled) at three US sites (Iowa City IA, Pittsburgh PA, Morgantown WV); mean age 30.7, mean pre-pregnancy BMI 27.3, 87.7% White, 77% college degree or higher, 84.5% privately insured
- Sitting 10+ h a dayhigherrisk rose steeply
- Light moving 5+ h/daylowerlinked, not proven
- Workouts or sleep timenoneno clear trend
More to know, from our read of the paper:
- Observational cohort: linked, not proven. Authors say interventions replacing sitting with light activity still need testing
- The 'optimal' day in the abstract (5.9 h sitting, 7.9 h light activity, 7 min MVPA, 10.1 h sleep) is the centre of the 0-5% best band; the Discussion instead cites ~8 h sitting + 7 h light (20-25% band). Do not present the 7 min of MVPA or 10 h 'sleep' (time in bed incl. naps) as a recommendation
- Light activity (LPA) includes static standing; authors say standing should be studied separately
- Sample mostly White, highly educated and higher income; diet not assessed; may be underpowered for BMI subgroups; results constrained to observed behaviour ranges
Less sitting, more light moving: lower risk.
470 pregnant people at three US sites wore activity and sleep trackers for a week in each trimester, and 86 (18.3%) went on to develop a high blood pressure disorder of pregnancy, such as preeclampsia. In the models, risk rose steeply above 10 hours a day of sitting or below 5 hours of light activity like standing and easy walking. Workouts and sleep time showed no clear trend in this study, though earlier exercise trials have found lower risk of high blood pressure in pregnancy. This is an observational cohort: linked, not proven.
Whitaker KM, Crisp AH, Gallagher J, Jones MA, Kim J, Wilhite K, Smith K, Rahman S, Thrower A, Catov J, Kline CE, Feghali M, Santillan D, Santillan M, Sheikh I, Zimmerman B, Barone Gibbs B (2026). Optimal 24-hour movement behaviour compositions across trimesters and risk of hypertensive disorders of pregnancy: the Pregnancy 24/7 cohort study. British Journal of Sports Medicine.
Design: Cohort study · prospective cohort (Pregnancy 24/7, NCT04749849) with device-measured 24-hour movement in each trimester and compositional (isometric log-ratio) binomial regression; predicted risks from model grids (linked, not proven)
DOI: 10.1136/bjsports-2025-111091
Goals:
We read the abstract and the full text of this paper and checked every number on this page against it (17 facts, checked on 2026-10-29). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.
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