title: Screening for trisomy 21 with maternal age, fetal nuchal translucency and maternal serum biochemistry at 11-14 weeks: a regional experience from Germany.
abstract: OBJECTIVE
  To examine the efficacy of first trimester screening for trisomy 21 using a combination of maternal age, fetal nuchal translucency (NT), maternal serum free beta-human chorionic gonadotropin (free beta-hCG) and pregnancy-associated plasma protein A (PAPP-A) in a regional setting [maternity unit of the Women's University Hospital, Hannover Medical School (study center); two regional private centers for prenatal diagnosis and human genetics; laboratory for prenatal diagnosis and human genetics].
  
  
  METHODS
  Fetal NT, crown-rump length, maternal serum free beta-hCG and PAPP-A were measured at 11-14 weeks of gestation. Risk calculation was carried out using the FMF computer algorithm. The patients were informed and counseled about possible invasive test options if the risk was 1 in 300 or greater. Fetal outcome was obtained by questionnaires given to the patients or sent to their gynecologists. The detection and false-positive rates for the different screening strategies were calculated.
  
  
  RESULTS
  Pregnancy outcome was obtained in 2,497 cases, of which 2,196 cases had completed first trimester screening with NT and maternal serum biochemistry and 301 additional cases had NT measurement only. The median age was 32.5 years. In our population 11 affected fetuses were found. The estimated risk for trisomy 21 was 1 in 300 or greater in 64, 82, 88 and 88% of affected fetuses using maternal age alone, in combination with nuchal translucency, with maternal serum biochemical markers or with both NT and biochemical markers for a false-positive rate of 28.2, 5.1, 15.3 and 4.0%.
  
  
  CONCLUSIONS
  First trimester screening using maternal age, NT, free beta-hCG and PAPP-A is highly effective for the detection of trisomy 21 and is associated with a sensitivity of about 90% for 5% false-positive patients.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Prenatal Medicine, Hannover Medical School, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Soergel
authors.forename: M
authors.initials: M
authors.lastname: Pruggmayer
authors.forename: R
authors.initials: R
authors.lastname: Schwerdtfeger
authors.forename: K
authors.initials: K
authors.lastname: Muhlhaus
authors.forename: A
authors.initials: A
authors.lastname: Scharf
mesh_terms: D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D018568:Crown-Rump Length; D004314:Down Syndrome / Q000175:diagnosis*; D005189:False Positive Reactions; D005260:Female; D005858:Germany; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011256:Pregnancy Outcome; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis*; D011296:Prenatal Diagnosis / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A