title: Effect of chorionic villus sampling on the occurrence of preeclampsia and gestational hypertension: An updated systematic review and meta-analysis.
abstract: OBJECTIVE
  To perform a meta-analysis for an assessment of the risk of preeclampsia or gestational hypertension following chorionic villus sampling (CVS).
  
  
  METHODS
  PubMed was systematically searched from its inception through January 2016.
  
  
  METHODS
  Nine reports were identified. A pre-specified scale was used to assess their quality.
  We performed pooling into three subgroups with respect to the control group: A) Patients with no invasive prenatal diagnostic procedure served as a control group for comparison. The odds ratios for gestational hypertension (0.76, 95% CI 0.46-1.26), preeclampsia (0.83, 95% CI 0.42-1.67), and severe preeclampsia (0.49, 95% CI 0.04-5.78) or when hypertension categories were pooled (0.80, 95% CI 0.46-1.41) were not significantly different. B) Patients with midtrimester diagnostic amniocentesis and patients with no invasive prenatal diagnostic procedure were combined as a control group for comparison. The odds ratios for preeclampsia (1, 95% CI 0.46-2.18), severe preeclampsia (0.83, 95% CI 0.14-4.85), and pooled hypertension categories (1.07, 95% CI 0.63-1.84) were not significantly different. C) Patients with midtrimester diagnostic amniocentesis served as a control group. There was a significant difference in the odds ratio for preeclampsia between the CVS and amniocentesis groups (2.47, 95% CI 1.14-5.33). There was a marginal difference in the odds ratio for combined pregnancy-induced hypertension categories between the CVS and amniocentesis groups (1.61, 95% CI 1.02-2.53).
  
  
  CONCLUSIONS
  The available data do not indicate an increased risk of preeclampsia or gestational hypertension following first trimester CVS. The heterogeneity and retrospective design of existing studies are limiting factors for our analysis and findings.
authors.affiliation: Department of Obstetrics and Gynecology, Konya Training and Research Hospital, Konya, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Başaran
authors.affiliation: Department of Obstetrics and Gynecology, Konya Training and Research Hospital, Konya, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Başaran
authors.affiliation: Department of Anesthesiology, Konya Training and Research Hospital, Konya, Turkey.
authors.forename: Betül
authors.initials: B
authors.lastname: Topatan
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA.
authors.forename: James N
authors.initials: JN
authors.lastname: Martin
keywords: Meta-analysis; chorionic villus sampling; midtrimester diagnostic amniocentesis; preeclampsia