title: Does leisure time physical activity in early pregnancy protect against pre-eclampsia? Prospective cohort in Danish women.
abstract: OBJECTIVE
  To examine the association between physical activity in early pregnancy and risk of pre-eclampsia.
  
  
  METHODS
  Prospective cohort.
  
  
  METHODS
  Denmark.
  
  
  METHODS
  A total of 85,139 pregnant Danish women, recruited between 1996 and 2002.
  
  
  METHODS
  The authors assessed leisure time physical activity in first trimester by a telephone interview and categorised women a priori into seven groups: 0 (reference), 1-44, 45-74, 75-149, 150-269, 270-419 and 420+ minutes/week. Pre-eclampsia diagnoses were extracted from the Danish National Patient Registry. A number of potential confounders were adjusted for by logistic regression.
  
  
  METHODS
  Pre-eclampsia and severe pre-eclampsia.
  
  
  RESULTS
  The two highest physical activity levels were associated with increased risk of severe pre-eclampsia compared with the nonexercising group, with adjusted odds ratios of 1.65 (95% CI: 1.11-2.43) and 1.78 (95% CI: 1.07-2.95), whereas more moderate levels of physical activity (1-270 minutes/week) had no statistically significant association with risk of pre-eclampsia (total n = 85,139).
  
  
  CONCLUSIONS
  We were unable to document a protective effect of leisure time physical activity against pre-eclampsia. Our data even suggest that leisure time physical activity exceeding 270 minutes/week in first trimester may increase risk of severe pre-eclampsia.
authors.affiliation: Maternal Nutrition Group, Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark. mae@ssi.dk
authors.forename: M L
authors.initials: ML
authors.lastname: Østerdal
authors.forename: M
authors.initials: M
authors.lastname: Strøm
authors.forename: A K
authors.initials: AK
authors.lastname: Klemmensen
authors.forename: V K
authors.initials: VK
authors.lastname: Knudsen
authors.forename: M
authors.initials: M
authors.lastname: Juhl
authors.forename: T I
authors.initials: TI
authors.lastname: Halldorsson
authors.forename: A-M
authors.initials: AM
authors.lastname: Nybo Andersen
authors.forename: P
authors.initials: P
authors.lastname: Magnus
authors.forename: S F
authors.initials: SF
authors.lastname: Olsen
mesh_terms: D000328:Adult; D003718:Denmark / Q000453:epidemiology; D004812:Epidemiologic Methods; D015444:Exercise; D005260:Female; D006801:Humans; D007899:Leisure Activities; D011225:Pre-Eclampsia / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D055815:Young Adult