title: Effectiveness of gestational diabetes treatment: a systematic review with quality of evidence assessment.
abstract: OBJECTIVE
  To evaluate the effectiveness of gestational diabetes (GDM) treatment compared to usual antenatal care, in the prevention of adverse pregnancy outcomes. Additionally, to assess the quality of the evidence to support GDM treatment according to GRADE guidelines.
  
  
  METHODS
  Fourteen electronic databases and reference lists of relevant literature were searched for articles published from inception to February, 2012. Controlled clinical trials comparing GDM treatment to usual antenatal care were included. Independent extraction of articles was done by two authors using predefined data fields.
  
  
  RESULTS
  Seven trials involving 3157 women were included. We found high quality evidence that treatment of GDM reduces macrosomia (RR=0.47; 95% CI, 0.34-0.65; NNT=11.4) and large for gestational age birth (RR=0.57; 95% CI, 0.47-0.71; NNT=12.2); moderate quality evidence that treatment reduces preeclampsia (RR=0.61; 95% CI, 0.46-0.81; NNT=21.0) and hypertensive disorders in pregnancy (RR=0.64; 95% CI, 0.51-0.81; NNT=18.1); and low quality evidence that treatment reduces shoulder dystocia (RR=0.41; 95% CI, 0.22-0.76; NNT=48.8). No statistically significant reduction was seen for caesarean section. No increase in small for gestational age or preterm birth was found.
  
  
  CONCLUSIONS
  Treatment of GDM is effective in reducing macrosomia (high quality evidence), preeclampsia and shoulder dystocia.
authors.affiliation: Post Graduate Program in Epidemiology, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos n. 2600, Porto Alegre, Brazil. mfalavigna@yahoo.com.br
authors.forename: Maicon
authors.initials: M
authors.lastname: Falavigna
authors.forename: Maria I
authors.initials: MI
authors.lastname: Schmidt
authors.forename: Janet
authors.initials: J
authors.lastname: Trujillo
authors.forename: Luísia F
authors.initials: LF
authors.lastname: Alves
authors.forename: Eliana R
authors.initials: ER
authors.lastname: Wendland
authors.forename: Maria R
authors.initials: MR
authors.lastname: Torloni
authors.forename: Stephen
authors.initials: S
authors.lastname: Colagiuri
authors.forename: Bruce B
authors.initials: BB
authors.lastname: Duncan
mesh_terms: D016640:Diabetes, Gestational / Q000503:physiopathology / Q000628:therapy*; D004420:Dystocia / Q000209:etiology / Q000517:prevention & control; D019317:Evidence-Based Medicine; D005260:Female; D005320:Fetal Macrosomia / Q000517:prevention & control; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000209:etiology / Q000517:prevention & control; D011225:Pre-Eclampsia / Q000209:etiology / Q000517:prevention & control; D011247:Pregnancy; D011256:Pregnancy Outcome; D016032:Randomized Controlled Trials as Topic