title: Impact of prenatal screening and diagnostic testing on trends in Down syndrome births and terminations in Western Australia 1980 to 2013.
abstract: OBJECTIVE
  To assess how prenatal screening and diagnostic testing have impacted the diagnosis, termination and birth prevalence of Down syndrome in Western Australia (1980-2013).
  
  
  METHODS
  We analysed trends in termination rates and birth prevalence of Down syndrome using aggregated data (1980-2013). We modelled the expected live-birth rate and prevalence of Down syndrome and compared different eras of screening and diagnosis with respect to the impact on live-birth rate and prevalence of Down syndrome.
  
  
  RESULTS
  Between 1980 and 2013, the rate of Down syndrome pregnancies increased, corresponding to a greater proportion of babies born to older women. Following the introduction of screening in 1994, the rate of live-born infants with Down syndrome reduced significantly (p = 0.001). The rate of terminations of pregnancy for Down syndrome remained stable over this period. In the absence of termination, the Down syndrome live-birth rate would have risen from 1.1 per 1000 to 2.17 per 1000 between 1980 and 2013.
  
  
  CONCLUSIONS
  Prenatal testing in Western Australia has reduced the birth prevalence of Down syndrome despite an increased rate of Down syndrome pregnancies. Most women for whom a prenatal diagnosis of fetal Down syndrome is made, chose to terminate the pregnancy (93%), and this proportion has not changed over the study period.
authors.affiliation: Health Policy and Management, School of Public Health, Faculty of Health Sciences, Curtin University, Perth, WA, Australia.
authors.forename: Susannah
authors.initials: S
authors.lastname: Maxwell
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Crawley, WA, Australia.|Western Australian Register of Developmental Anomalies, Perth, WA, Australia.
authors.forename: Carol
authors.initials: C
authors.lastname: Bower
authors.affiliation: Health Policy and Management, School of Public Health, Faculty of Health Sciences, Curtin University, Perth, WA, Australia.|School of Women's and Infants' Health, The University of Western Australia, Crawley, WA, Australia.|Clinical Biochemistry, PathWest Laboratory Medicine, Princess Margaret Hospital for Children, Nedlands, WA, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: O'Leary
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data; D004314:Down Syndrome / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000191:economics / Q000706:statistics & numerical data*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014904:Western Australia / Q000453:epidemiology