title: Effect of diet- and lifestyle-based metabolic risk-modifying interventions on preeclampsia: a meta-analysis.
abstract: OBJECTIVE
  To evaluate the effect of dietary and lifestyle interventions with the potential to modify metabolic risk factors on the risk of preeclampsia.
  
  
  METHODS
  We searched MEDLINE, EMBASE and Cochrane from inception until February 2013. Randomized trials in pregnant women evaluating the effect of dietary and lifestyle interventions with the potential to modify metabolic risks such as obesity, hyperlipidemia, hyperglycemia and hypertension on the risk of preeclampsia were included.
  
  
  METHODS
  Two independent reviewers selected studies, extracted data and assessed quality. Results were summarized as pooled relative risks (RR) for dichotomous data.
  
  
  RESULTS
  Eighteen studies (8712 women) met our search criteria for inclusion. Six studies evaluated diet (2695 women), six studied mixed interventions with diet, physical activity and lifestyle (1438 women) and six assessed essential fatty acid supplementation (4579 women). The interventions overall reduced the risk of preeclampsia (RR 0.81, 95% CI 0.69-0.94; p = 0.006 I(2) = 0%) compared with the control group. Dietary interventions reduced the risk of preeclampsia by 33% (RR 0.67, 95% CI 0.53-0.85; p = 0.001; I(2) = 0%). There was no reduction in the risk of preeclampsia with mixed interventions (RR 0.93, 95% CI 0.66-1.32, p = 0.68, I(2) = 0%) or fatty acid supplementation (RR 0.92, 95% CI 0.71-1.18; p = 0.49, I(2) = 15%). Meta-regression showed a borderline impact of gestational diabetes status (p = 0.05) on the observed effect.
  
  
  CONCLUSIONS
  Dietary and lifestyle interventions have the potential to reduce the risk of preeclampsia. The effect of additional therapeutic interventions in women with gestational diabetes mellitus on preeclampsia is not known.
authors.affiliation: Barts Health NHS Trust, London, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Allen
authors.forename: Ewelina
authors.initials: E
authors.lastname: Rogozinska
authors.forename: Priya
authors.initials: P
authors.lastname: Sivarajasingam
authors.forename: Khalid S
authors.initials: KS
authors.lastname: Khan
authors.forename: Shakila
authors.initials: S
authors.lastname: Thangaratinam
mesh_terms: D015987:Effect Modifier, Epidemiologic; D005247:Feeding Behavior / Q000502:physiology / Q000523:psychology; D005260:Female; D006801:Humans; D008019:Life Style; D024821:Metabolic Syndrome / Q000150:complications / Q000178:diet therapy / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D040242:Risk Reduction Behavior
keywords: Diet; essential fatty acids; lifestyle; lipids; preeclampsia