title: First-trimester maternal dried blood Down syndrome screening marker levels in early pregnancy loss.
abstract: OBJECTIVE
  To determine the association of free beta hCG and PAPP-A measured during first-trimester Down syndrome risk assessment with early pregnancy loss when blood is drawn prior to scheduled ultrasound.
  
  
  METHODS
  Maternal dried blood samples were collected prior to the ultrasound exam for Down syndrome risk assessment. Free beta hCG and PAPP-A levels in 55 patients who experienced loss of pregnancy prior to their scheduled ultrasound appointment were compared to 6464 control pregnancies using logistic regression.
  
  
  RESULTS
  Low levels of free beta hCG and PAPP-A were associated with increased risk of early pregnancy loss. The detection rate of early pregnancy loss for a fixed 5% false-positive rate using free beta alone, PAPP-A alone and a combination of the two were 47, 36 and 49%, respectively.
  
  
  CONCLUSIONS
  Free beta hCG and PAPP-A can identify pregnancies at increased risk for early pregnancy loss. More studies are needed to determine whether further evaluation of these pregnancies prior to the scheduled ultrasound is warranted.
authors.affiliation: Research Division, NTD Laboratories, Huntington Station, NY 11746, USA. dakrantz@ntdlabs.com
authors.forename: David
authors.initials: D
authors.lastname: Krantz
authors.forename: Terrence
authors.initials: T
authors.lastname: Hallahan
authors.forename: Stephanie
authors.initials: S
authors.lastname: Ishack
authors.forename: V James
authors.initials: VJ
authors.lastname: Macri
authors.forename: James N
authors.initials: JN
authors.lastname: Macri
mesh_terms: D000022:Abortion, Spontaneous / Q000097:blood / Q000175:diagnosis*; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001800:Blood Specimen Collection / Q000379:methods; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D004314:Down Syndrome / Q000097:blood; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis*; D011296:Prenatal Diagnosis / Q000379:methods*; D012044:Regression Analysis; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A