title: Maternal body mass index and the risk of preeclampsia: a systematic overview.
abstract: BACKGROUND
  Maternal obesity, both in itself and as part of the insulin resistance syndrome, is an important risk factor for the development of preeclampsia. Accurately quantifying the relation between prepregnancy maternal body mass index and the risk of preeclampsia may better identify those at highest risk. We performed a systematic overview of the literature to determine the association between prepregnancy body mass index and the risk of preeclampsia.
  
  
  METHODS
  Two reviewers independently retrieved all relevant English language cohort studies through a systematic search of Medline and Embase between 1980 and June 2002. Study data were abstracted in a similar fashion. For each study, the risk ratio of preeclampsia was calculated by comparing the risk of preeclampsia among women with the highest body mass index with those with the lowest.
  
  
  RESULTS
  We identified thirteen cohort studies, comprising nearly 1.4 million women. The risk of preeclampsia typically doubled with each 5-7 kg/m2 increase in prepregnancy body mass index. This relation persisted in studies that excluded women with chronic hypertension, diabetes mellitus or multiple gestations, or after adjustment for other confounders.
  
  
  CONCLUSIONS
  Most observational studies demonstrate a consistently strong positive association between maternal prepregnancy body mass index and the risk of preeclampsia. Increasing obesity in developed countries is likely to increase the occurrence of preeclampsia. Consideration should be given to the potential benefits of prepregnancy weight reduction programs.
authors.affiliation: Division of Obstetrical Medicine, Department of Medicine, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario, Canada. tara.obrien@swchsc.on.ca
authors.forename: Tara E
authors.initials: TE
authors.lastname: O'Brien
authors.forename: Joel G
authors.initials: JG
authors.lastname: Ray
authors.forename: Wee-Shian
authors.initials: WS
authors.lastname: Chan
mesh_terms: D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D009765:Obesity / Q000150:complications; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D015995:Prevalence; D012307:Risk Factors