title: The prevalence of congenital uterine anomalies in unselected and high-risk populations: a systematic review.
abstract: BACKGROUND
  The prevalence of congenital uterine anomalies in high-risk women is unclear, as several different diagnostic approaches have been applied to different groups of patients. This review aims to evaluate the prevalence of such anomalies in unselected populations and in women with infertility, including those undergoing IVF treatment, women with a history of miscarriage, women with infertility and recurrent miscarriage combined, and women with a history of preterm delivery.
  
  
  METHODS
  Searches of MEDLINE, EMBASE, Web of Science and the Cochrane register were performed. Study selection and data extraction were conducted independently by two reviewers. Studies were grouped into those that used 'optimal' and 'suboptimal' tests for uterine anomalies. Meta-analyses were performed to establish the prevalence of uterine anomalies and their subtypes within the various populations.
  
  
  RESULTS
  We identified 94 observational studies comprising 89 861 women. The prevalence of uterine anomalies diagnosed by optimal tests was 5.5% [95% confidence interval (CI), 3.5-8.5] in the unselected population, 8.0% (95% CI, 5.3-12) in infertile women, 13.3% (95% CI, 8.9-20.0) in those with a history of miscarriage and 24.5% (95% CI, 18.3-32.8) in those with miscarriage and infertility. Arcuate uterus is most common in the unselected population (3.9%; 95% CI, 2.1-7.1), and its prevalence is not increased in high-risk groups. In contrast, septate uterus is the most common anomaly in high-risk populations.
  
  
  CONCLUSIONS
  Women with a history of miscarriage or miscarriage and infertility have higher prevalence of congenital uterine anomalies compared with the unselected population.
authors.affiliation: Department of Obstetrics and Gynaecology, Nottingham University Hospitals NHS Trust, Queen's Medical Centre Campus, Derby Road, Nottingham NG7 2UH, UK. yeeyin@gmail.com
authors.forename: Y Y
authors.initials: YY
authors.lastname: Chan
authors.forename: K
authors.initials: K
authors.lastname: Jayaprakasan
authors.forename: J
authors.initials: J
authors.lastname: Zamora
authors.forename: J G
authors.initials: JG
authors.lastname: Thornton
authors.forename: N
authors.initials: N
authors.lastname: Raine-Fenning
authors.forename: A
authors.initials: A
authors.lastname: Coomarasamy
mesh_terms: D000022:Abortion, Spontaneous / Q000209:etiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007247:Infertility, Female / Q000453:epidemiology / Q000209:etiology; D011247:Pregnancy; D047928:Premature Birth / Q000209:etiology; D015995:Prevalence; D012307:Risk Factors; D014564:Urogenital Abnormalities / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology; D014599:Uterus / Q000002:abnormalities*