Introduction: Physical activity (PA) during first 20 weeks of pregnancy may lower risks of gestational diabetes mellitus (GDM) and gestational hypertension (GH), though evidence of association remains inconclusive. Current studies rely heavily on subjective assessment of PA levels. Wearable activity trackers provide a convenient and objective surrogate index for PA validated by evidence-based steps/day categorisation along a physical inactivity/activity continuum. I-ACT primarily aims to examine objectively measured PA levels and patterns in first and second trimesters of pregnancy and the association with GDM and/or GH in Singapore, a multiethnic Asian population. Secondary aims include investigating the bio-socio-demographic factors associated with sedentary behaviour, and association of early pregnancy PA level with maternal weight at 6 weeks postdelivery. Results may facilitate identification of high-risk mothers-to-be and formulation of interventional strategies.
Methods and analysis: Prospective cohort study that will recruit 408 women at first antenatal visit at <12 weeks' gestation. Baseline bio-socio-demographic factors and PA levels assessed by participant characteristics form and the International Physical Activity Questionnaire (IPAQ), respectively. An activity tracker (Fitbit) will be provided to be worn daily from date of recruitment to end of 20 weeks' gestation. Tracker-recorded data will be synchronised with an application on participant's smartphone. Compliance will be reinforced with fortnightly reminders. After 20 weeks, a second IPAQ and a feedback form will be administered. GDM screened at 24-28 weeks' gestation. GH diagnosed after 20-weeks gestation. Maternal weight assessed at 6 weeks postdelivery. Appropriate statistical tests will be used to compare continuous and categorical PA measurements between first and second trimesters. Logistic regression will be used to analyse associations.
Ethics and dissemination: Ethical approval obtained from the Centralised Institutional Review Board of SingHealth (reference 2017/2836). Dissemination of results will be via peer-reviewed research publications both online and in print, conference presentations, posters and medical forums.
Keywords: diabetes in pregnancy; maternal medicine; preventive medicine; primary care.
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