title: Association between polycystic ovary syndrome and the risk of pregnancy complications: A PRISMA-compliant systematic review and meta-analysis.
abstract: BACKGROUND
  Polycystic ovary syndrome (PCOS) is inconsistently associated with increased risk of adverse pregnancy outcomes. The purpose of this meta-analysis was to summarize the evidence regarding the strength of the association between pregnancy in women with PCOS and pregnancy complications.
  
  
  METHODS
  We systematically searched PubMed, EmBase, and the Cochrane Library to identify observational studies up to January 2016. The primary focus was pregnancy outcomes, including gestational diabetes mellitus (GDM), preeclampsia, pregnancy-induced hypertension (PIH), preterm delivery, cesarean delivery, oligohydramnios, and polyhydramnios. Effect estimates were pooled using the random-effects model. The analysis was further stratified by factors that could affect these associations.
  
  
  RESULTS
  We included 40 observational studies that reported data on a total of 17,816 pregnancies with PCOS and 123,756 pregnancies without PCOS. Overall, PCOS in pregnancy was associated with greater risk of GDM, preeclampsia, PIH, preterm delivery, cesarean delivery, miscarriage, hypoglycemia, and perinatal death. However, PCOS in pregnancy had little or no effect on oligohydramnios, polyhydramnios, large-for-gestational age (LGA), small-for-gestational-age (SGA), fetal growth restriction (FGR), preterm premature membrane rupture, fasting blood glucose (FBG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride, total cholesterol, congenital malformation, macrosomia, and respiratory distress syndrome. Subgroup analysis suggested that these associations might be influenced by study design and pre-BMI.
  
  
  CONCLUSIONS
  PCOS in pregnancy is associated with a significantly increased risk of adverse pregnancy, fetal, and neonatal outcomes.
authors.affiliation: Department of Urosurgery Department of Cardiothoracic Surgery Medical Laboratory Center, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Yu
authors.forename: Hong-Su
authors.initials: HS
authors.lastname: Chen
authors.forename: Da-Pang
authors.initials: DP
authors.lastname: Rao
authors.forename: Jian
authors.initials: J
authors.lastname: Gong
mesh_terms: D016640:Diabetes, Gestational / Q000209:etiology; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000209:etiology; D007752:Obstetric Labor, Premature / Q000209:etiology; D011085:Polycystic Ovary Syndrome / Q000150:complications*; D011225:Pre-Eclampsia / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology*; D012307:Risk Factors