P01.04: Nasal bone assessment in first trimester detection of trisomy 21 (original) (raw)
Related papers
Nasal bone assessment in prenatal screening for trisomy 21
American Journal of Obstetrics and Gynecology, 2006
A small nose is a common facial feature of individuals with trisomy 21. Evidence based on radiologic, histomorphologic, and sonographic studies shows that nasal bone abnormalities are significantly more common in trisomy 21 fetuses than in euploid fetuses. These abnormalities, which include both nasal bone absence and short nasal bone length, can be detected by prenatal ultrasound. In this article we review the evidence and discuss the potential value of assessment of the fetal nasal bone in screening for trisomy 21.
Prenatal Diagnosis, 2003
Background Screening for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free β-hCG and pregnancy-associated plasma protein-A (PAPP-A) at 11 to 14 weeks of gestation is associated with a detection rate of 90% for a false-positive rate of 5%. Recent evidence suggests that in about 70% of fetuses with trisomy 21, the nasal bone is not visible at the 11th-to 14th-week scan . The aim of this study was to examine whether fetal NT thickness and the level of maternal serum biochemical markers is independent of the presence or absence of the nasal bone, and to estimate the performance of a screening test that integrates the two sonographic and the two biochemical markers.
Ultrasound in Obstetrics and Gynecology, 2007
Objective To determine the best measure of fetal nasal bone hypoplasia for trisomy 21 risk assessment in the second trimester. Methods This was a prospective, observational study performed at a single institution between February 2003 and December 2005. Fetuses with nasal bone length recorded sonographically between 16 and 20.9 weeks and known karyotype were included. Definitions of nasal bone hypoplasia assessed included: non-visualized nasal bone, nasal bone < 10 th percentile, nasal bone < 2.5 th percentile, biparietal diameter/nasal bone ratio ≥ 10 and ≥ 11 and nasal bone multiples of the median (MoM) ≤ 0.5, ≤ 0.6, and ≤ 0.7. Results A total of 371 chromosomally normal and 11 trisomy 21 fetuses were included. Nasal bone hypoplasia based on MoM was superior to the other measures of hypoplasia for trisomy 21 risk assessment as reflected by a higher positive likelihood ratio. The risk for fetal trisomy 21 was higher with greater degrees of nasal bone hypoplasia. Conclusion Hypoplasia, as defined by MoM, is the superior approach when incorporating nasal bone evaluation into fetal trisomy 21 risk assessment in the second trimester.
Nasal bone hypoplasia in trisomy 21 at 15-22 weeks gestation
… in Obstetrics and …, 2003
Ultrasound Obstet Gynecol 2003; 21: 15–18 Published online 18 December 2002 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/uog.19 ... Nasal bone hypoplasia in trisomy 21 at 15–22 weeks' ... S. CICERO*, JD SONEK† ‡ §, DS MCKENNA‡§, CS CROOM‡§, L. ...