title: Maternal serum placental growth factor and α-fetoprotein testing in first trimester screening for Down syndrome.
abstract: OBJECTIVE
  The aim of this research was to evaluate the addition of first trimester maternal serum placental growth factor (PlGF) and α-fetoprotein (AFP) to the combined test for Down syndrome and a serum only protocol of PlGF, AFP, free β-human chorionic gonadotropin and pregnancy-associated plasma protein-A.
  
  
  METHODS
  Samples were from 92 Down syndrome cases with 552 matched controls. All women had a combined test at 11-14 weeks gestation. PlGF and AFP were measured and expressed in multiples of the gestation-specific median (MoM), adjusting for maternal weight and smoking status. Multivariate Gaussian modeling was used to predict detection and false-positive rates.
  
  
  RESULTS
  The median PlGF level in the cases was 0.694 MoM and controls 1.000 MoM (p = <0.0001). The corresponding values for AFP were 0.764 MoM and 0.990 MoM (p < 0.0001). Statistical modeling predicted that for a given false-positive rate, the addition of PlGF to the combined test increases the detection rate by 4-7%. For a given detection rate, the false-positive rate could be almost halved. When both PlGF and AFP are used, the detection rate increase is 5-8%. A serum only protocol had a predicted a detection rate of 71% for a false-positive rate of 5%.
  
  
  CONCLUSIONS
  Results suggest a substantial benefit of adding PlGF to the combined test.
authors.affiliation: Biochemistry Department, Royal Victoria Infirmary, Newcastle, UK. kim.donalson@nuth.nhs.uk
authors.forename: Kim
authors.initials: K
authors.lastname: Donalson
authors.forename: Steve
authors.initials: S
authors.lastname: Turner
authors.forename: Lesley
authors.initials: L
authors.lastname: Morrison
authors.forename: Päivi
authors.initials: P
authors.lastname: Liitti
authors.forename: Christel
authors.initials: C
authors.lastname: Nilsson
authors.forename: Howard
authors.initials: H
authors.lastname: Cuckle
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis*; D005189:False Positive Reactions; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D000072483:Placenta Growth Factor; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000097:blood*; D011261:Pregnancy Trimester, First / Q000097:blood*; D011296:Prenatal Diagnosis; D055815:Young Adult; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: C000608036:PGF protein, human; D011257:Pregnancy Proteins; D000509:alpha-Fetoproteins; D000072483:Placenta Growth Factor