title: The effect of leisure time physical activity on the risk of pre-eclampsia and gestational hypertension.
abstract: OBJECTIVE
  To assess the relation between leisure time physical activity (LTPA) during the first 20 weeks of pregnancy and the risk of developing pre-eclampsia and gestational hypertension.
  
  
  METHODS
  Case-control study carried out over a 28 month period with retrospective data collection.
  
  
  METHODS
  Six hospitals in Quebec City and four hospitals in Montreal.
  
  
  METHODS
  172 women with pre-eclampsia, 254 with gestational diabetes, 505 controls. All were primiparous, with no history of high blood pressure before pregnancy (unless due to oral contraceptive use), or during the first 20 weeks of gestation. Cases were defined using recognised criteria, and 97% of those eligible agreed to be interviewed. Controls delivered in same hospital immediately after cases and had no more than one reading of elevated blood pressure during pregnancy; 96% of those eligible agreed to be interviewed.
  
  
  RESULTS
  Participants were interviewed in hospital a few days after delivery using a questionnaire. Information was collected on type, frequency and average duration of any LTPA performed regularly during the first 20 weeks of pregnancy, together with medical, obstetric and sociodemographic details. It was found that women who performed regular LTPA had a reduced risk of pre-eclampsia (adjusted RR 0.67, 95% CI 0.46-0.96) and gestational hypertension (aRR 0.75, 95% CI 0.54-1.05), and the relative risks decreased as the average time spent in LTPA increased (aRR for pre-eclampsia among women with low, moderate and high energy expenditure: 1.00, 0.77 and 0.57, p = 0.01). The same trend was present for gestational hypertension (1.00, 0.80 and 0.71, respectively, p = 0.08).
  
  
  CONCLUSIONS
  Leisure time physical activity during the first half of pregnancy is likely to reduce the risk of pre-eclampsia and gestational hypertension.
authors.affiliation: Department of Social and Preventive Medicine, Laval University, Quebec, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Marcoux
authors.forename: J
authors.initials: J
authors.lastname: Brisson
authors.forename: J
authors.initials: J
authors.lastname: Fabia
mesh_terms: D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D007899:Leisure Activities; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology*; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D012307:Risk Factors