title: Nutritional manipulation for the primary prevention of gestational diabetes mellitus: a meta-analysis of randomised studies.
abstract: BACKGROUND
  The rise in gestational diabetes (GDM), defined as first onset or diagnosis of diabetes in pregnancy, is a global problem. GDM is often associated with unhealthy diet and is a major contributor to adverse outcomes maternal and fetal outcomes. Manipulation of nutrition has the potential to prevent GDM.
  
  
  METHODS
  We assessed the effects of nutritional manipulation in pregnancy on GDM and relevant maternal and fetal outcomes by a systematic review of the literature. We searched MEDLINE, EMBASE, and Cochrane Database from inception to March 2014 without any language restrictions. Randomised controlled trials (RCT) of nutritional manipulation to prevent GDM were included. We summarised dichotomous data as relative risk (RR) and continuous data as standardised mean difference (SMD) with 95% confidence interval (CI).
  
  
  RESULTS
  From 1761 citations, 20 RCTs (6,444 women) met the inclusion criteria. We identified the following interventions: diet-based (n = 6), mixed approach (diet and lifestyle) interventions (n = 13), and nutritional supplements (myo-inositol n = 1, diet with probiotics n = 1). Diet based interventions reduced the risk of GDM by 33% (RR 0.67; 95% CI 0.39, 1.15). Mixed approach interventions based on diet and lifestyle had no effect on GDM (RR 0.95; 95% CI 0.89, 1.22). Nutritional supplements probiotics combined with diet (RR 0.40; 95% CI 0.20, 0.78) and myo-inositol (RR 0.40; 95% CI 0.16, 0.99) were assessed in one trial each and showed a beneficial effect. We observed a significant interaction between the groups based on BMI for diet-based intervention. The risk of GDM was reduced in obese and overweight pregnant women for GDM (RR 0.40, 95% CI 0.18, 0.86).
  
  
  CONCLUSIONS
  Nutritional manipulation in pregnancy based on diet or mixed approach do not appear to reduce the risk of GDM. Nutritional supplements show potential as agents for primary prevention of GDM.
authors.affiliation: Women's Health Research Unit, Centre of Primary Care and Public Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom; Multidisciplinary Evidence Synthesis Hub (mEsh), Centre of Primary Care and Public Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Rogozińska
authors.affiliation: Centro Rosarino Estudios Perinatales, Rosario, Santa Fe, Argentina.
authors.forename: Monica
authors.initials: M
authors.lastname: Chamillard
authors.affiliation: Centre of Diabetes, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.
authors.forename: Graham A
authors.initials: GA
authors.lastname: Hitman
authors.affiliation: Women's Health Research Unit, Centre of Primary Care and Public Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom; Multidisciplinary Evidence Synthesis Hub (mEsh), Centre of Primary Care and Public Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom.
authors.forename: Khalid S
authors.initials: KS
authors.lastname: Khan
authors.affiliation: Women's Health Research Unit, Centre of Primary Care and Public Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom; Multidisciplinary Evidence Synthesis Hub (mEsh), Centre of Primary Care and Public Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom.
authors.forename: Shakila
authors.initials: S
authors.lastname: Thangaratinam
mesh_terms: D002986:Clinical Trials as Topic; D016208:Databases, Factual; D016640:Diabetes, Gestational / Q000175:diagnosis / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007294:Inositol / Q000008:administration & dosage; D015596:Nutrition Assessment; D009765:Obesity / Q000150:complications; D011247:Pregnancy; D011322:Primary Prevention; D019936:Probiotics / Q000008:administration & dosage; D012306:Risk
chemical_list: D007294:Inositol