Antenatal detection of Edwards (Trisomy 18) and Patau (Trisomy 13) syndrome: England and Wales 2005-2012

ObjectivesPregnancies with Edwards or Patau syndrome are often detected through screening for Down’s syndrome. We aimed to evaluate the impact of screening for Down’s syndrome on the prevalence of live births and antenatal diagnoses of Edwards and Patau syndrome.SettingEngland and Wales, 2005 to 2012.MethodsData from the National Down Syndrome Cytogenetic Register, which contains information on nearly all ante- or postnatally diagnosed cases of Edwards or Patau syndrome in which a karyotype was confirmed, were analysed.ResultsFrom 2005 to 2012, 3,941 diagnoses of Edwards syndrome and 1,567 diagnoses of Patau syndrome were recorded (prevalence of 7.0 and 2.8 per 10,000 births respectively). Only 11% (95% confidence interval [CI]: 10–12) of diagnoses of Edwards syndrome and 13% (95% CI: 11–14) of Patau syndrome were live births, resulting in live birth prevalences of 0.8 (95% CI: 0.7–0.8) and 0.4 (95% CI: 0.3–0.4) per 10,000 live births respectively. About 90% of pregnancies with Edwards or Patau syndrome w...