title: Significant changes in physical activity among pregnant women in the UK as assessed by accelerometry and self-reported activity.
abstract: OBJECTIVE
  Research on the impact of maternal physical activity on pregnancy outcomes has often employed subjective measures of physical activity obtained by diary or questionnaire. This study investigates the feasibility of using accelerometry as an objective measure of physical activity of pregnant women compared with subjective data obtained via activity recall among pregnant women.
  
  
  METHODS
  Activity data were collected prospectively on 57 women at 12, 16, 25, 34 and 38 weeks of gestation. Total daily physical activity was assessed by ambulatory accelerometer and activity interview (self-report). Maternal personality variables (health value, extroversion) were assessed by established scales.
  
  
  METHODS
  Leicestershire, UK.
  
  
  METHODS
  Pregnant women were recruited by voluntary participation via antenatal booking clinics. In all, 64 pregnant women with low-risk pregnancy were enrolled onto the study, of whom 57 completed the study.
  
  
  RESULTS
  Mean 24 h physical activity levels (PAL) decreased significantly from second to third trimester as assessed by self-report interview (1.51-1.29 Metabolic Equivalent TEE-h/day, P<0.01) and accelerometry (200.05-147.42 counts/min, P<0.01). The correlation between the two measures declined as pregnancy progressed (r value ranging from 0.55 to 0.08). Compliance with the accelerometers declined from 90% at 12 weeks to 47% at 34 weeks (P<0.01). Compliance with the self-report interviews was 100%. Those who fully complied with the accelerometry demonstrated a significantly higher health value (P<0.05) and a significantly greater level of extroversion (P<0.05) than those who did not.
  
  
  CONCLUSIONS
  Accelerometers and self-reported activity interviews both indicated a significant decline in PAL during pregnancy. Although subjects showed a willingness to use both methods, accelerometers resulted in variable compliance with 72 h monitoring. Both techniques may be limited by the need to measure low levels of physical activity during the third trimester.
  
  
  BACKGROUND
  Cambridge Neurotechnology Ltd, UK, assisted with the provision of Actiwatch accelerometers.
authors.affiliation: Department of Human Sciences, Loughborough University, Loughborough, Leicestershire, UK. e.k.rousham@lboro.ac.uk
authors.forename: E K
authors.initials: EK
authors.lastname: Rousham
authors.forename: P E
authors.initials: PE
authors.lastname: Clarke
authors.forename: H
authors.initials: H
authors.lastname: Gross
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D005260:Female; D015438:Health Behavior; D006801:Humans; D011939:Mental Recall; D010349:Patient Compliance; D011247:Pregnancy / Q000502:physiology*; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First / Q000502:physiology; D011262:Pregnancy Trimester, Second / Q000502:physiology; D011263:Pregnancy Trimester, Third / Q000502:physiology; D011264:Pregnancy Trimesters / Q000502:physiology*; D011446:Prospective Studies; D012650:Self Disclosure; D006113:United Kingdom; D015430:Weight Gain / Q000502:physiology; D016387:Women's Health