title: Screening for chromosomal abnormalities in the first trimester using ultrasound and maternal serum biochemistry in a one-stop clinic: a review of three years prospective experience.
abstract: OBJECTIVE
  To evaluate the performance of a one-stop multidisciplinary clinic of screening for fetal chromosomal anomalies in the first trimester of pregnancy by a combination of maternal serum biochemistry and ultrasonography.
  
  
  METHODS
  Retrospective review of screening performance.
  
  
  METHODS
  District General Hospital maternity unit.
  
  
  METHODS
  All women booked for routine antenatal care at Harold Wood Hospital between 1 June 1998 and 31 May 2001. The population included 12,339 women with singleton pregnancies presenting at 10-14 weeks of gestation.
  
  
  METHODS
  Women were offered screening using a combination of maternal serum free beta-hCG and pregnancy associated plasma protein-A (PAPP-A) and fetal nuchal translucency thickness. Those with an estimated risk of >/=1 in 300 of carrying a fetus with trisomy 21 or trisomy 18 or trisomy 13 were offered the option of an invasive diagnostic test. Follow up of the outcome of all pregnancies was carried out.
  
  
  METHODS
  Uptake of screening and invasive testing, detection rate for fetal chromosomal abnormalities and false positive rate.
  
  
  RESULTS
  The uptake of first trimester screening was 97.5% and the uptake of invasive testing in the increased risk group was 77%. The rate of detection of trisomy 21 was 92% (23 of 25), of trisomy 13 or 18 was 100% (all 15) and of all aneuploidies was 96% (49 of 51). The false positive rate was 5.2%.
  
  
  CONCLUSIONS
  First trimester screening for trisomy 21 and other aneuploidies can be delivered in an efficient manner in a one-stop multidisciplinary clinic. The detection rates are far better than can be achieved by second trimester serum screening.
authors.affiliation: Department of Clinical Biochemistry, Harold Wood Hospital, Essex, UK.
authors.forename: Kevin
authors.initials: K
authors.lastname: Spencer
authors.forename: Christine E
authors.initials: CE
authors.lastname: Spencer
authors.forename: Maureen
authors.initials: M
authors.lastname: Power
authors.forename: Carolynne
authors.initials: C
authors.lastname: Dawson
authors.forename: Kypros H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D017677:Age Distribution; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D025063:Chromosome Disorders / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008423:Maternal Age; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis; D011296:Prenatal Diagnosis / Q000379:methods*; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D016216:Ultrasonography, Prenatal / Q000379:methods
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A