Early pregnancy screening for fetal aneuploidy with serum markers and nuchal translucency

Prenat Diagn. 1999 May;19(5):458-62. doi: 10.1002/(sici)1097-0223(199905)19:5<458::aid-pd569>3.0.co;2-a.


We determined the aneuploidy detection rate achievable by early pregnancy screening with pregnancy associated plasma protein (PAPP)-A, free beta human chorionic gonadotrophin (hCG) and ultrasound nuchal translucency (NT) measurement. Women having prenatal diagnosis were scanned, and a blood sample was taken and stored. Stored samples were tested and a total of 37 were found to have Down syndrome, 8 to have Edwards syndrome and 255 were controls. Results were expressed in multiples of the gestation-specific median (MOM) value in the controls after regression and, for the serum markers, maternal weight adjustment. In Down syndrome the medians were for PAPP-A 0.63 MOM (95 per cent confidence interval (CI) 0.45-0.87); free beta-hCG 1.88 MOM (1.33-2.66); and NT 2.34 MOM (1.70-3.22). Using these parameters the expected detection rate for a 5 per cent false-positive rate for different marker combinations were: 55.3 per cent for PAPP-A and free beta-hCG; 68.4 per cent for NT alone; and 84.6 per cent for PAPP-A, free beta-hCG and NT. The median values for Edwards syndrome were: 0.17 MOM for PAPP-A; 0.18 MOM for free beta-hCG; and 2.64 MOM for NT. Early pregnancy screening with the combined measurement of maternal serum PAPP-A and free beta-hCG and fetal nuchal translucency could achieve a high Down syndrome detection rate.

MeSH terms

  • Aneuploidy
  • Biomarkers / analysis*
  • Case-Control Studies
  • Chorionic Gonadotropin, beta Subunit, Human / blood
  • Down Syndrome / blood*
  • Down Syndrome / diagnostic imaging*
  • Down Syndrome / genetics
  • Female
  • Fetal Diseases / blood
  • Fetal Diseases / diagnosis*
  • Fetal Diseases / genetics
  • Humans
  • Normal Distribution
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy-Associated Plasma Protein-A / analysis
  • Prenatal Diagnosis / statistics & numerical data*
  • Retrospective Studies
  • Ultrasonography
  • alpha-Fetoproteins / analysis


  • Biomarkers
  • Chorionic Gonadotropin, beta Subunit, Human
  • alpha-Fetoproteins
  • Pregnancy-Associated Plasma Protein-A