title: Additional first-trimester ultrasound markers.
abstract: The first trimester (11-13 +6 weeks) ultrasound examination is useful for several reasons: determination of an accurate date of confinement, diagnostic purposes, and screening for fetal defects. Nuchal translucency measurement combined with maternal serum markers (free b-human chorionic gonadotropin and pregnancy-associated plasma protein A) is the mainstay of first-trimester screening for chromosomal defects. However, over the past decade additional ultrasound markers have been developed that improve the performance of this type of screening. The novel markers include evaluation of the nasal bone, fronto-maxillary angle measurement, and Doppler evaluations of the blood flow across the tricuspid valve and in the ductus venosus.
authors.affiliation: Wright State University, Dayton, OH, USA. jdsonek@mvh.org
authors.forename: J
authors.initials: J
authors.lastname: Sonek
authors.forename: K
authors.initials: K
authors.lastname: Nicolaides
mesh_terms: D015415:Biomarkers / Q000032:analysis; D004314:Down Syndrome / Q000175:diagnosis / Q000000981:diagnostic imaging; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging; D006801:Humans; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000196:embryology; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D016216:Ultrasonography, Prenatal / Q000379:methods* / Q000592:standards
chemical_list: D015415:Biomarkers