One-stop clinic for assessment of risk of chromosomal defects at 12 weeks of gestation.
Prenatal diagnosis of trisomy 21 requires an invasive test in women considered to be at high risk after screening. At present, there are four screening tests. For a 5% false-positive rate, the sensitivities are approximately 30% for maternal age alone, 60-70% for maternal age and second-trimester maternal serum biochemical testing, 75% for maternal age and first-trimester fetal nuchal translucency (NT) scanning, and 90% for maternal age with fetal NT and maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11-14 weeks. This article examines the methodology of first-trimester screening and summarizes the results from all studies reporting on the implementation of this method.
Nicolaides
K H
KH
Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, King's College London, UK.
Bindra
R
R
Heath
V
V
Cicero
S
S
D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D004314:Down Syndrome / Q000175:diagnosis*; D005189:False Positive Reactions; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D009333:Neck / Q000000981:diagnostic imaging / Q000196:embryology; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D018566:Pregnancy, High-Risk; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism; D011296:Prenatal Diagnosis / Q000379:methods / Q000592:standards; D012680:Sensitivity and Specificity; D014463:Ultrasonography
D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A