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Ultrasonographic evaluation of fetal nasal bone in a low‐risk population at 11–13 + 6 gestational weeks
Author(s) -
RamosCorpas Domingo,
Santiago Juan C.,
Montoya Francisco
Publication year - 2006
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.1345
Subject(s) - nasal bone , medicine , fetus , population , gestational age , obstetrics , pregnancy , gynecology , surgery , biology , genetics , environmental health
Abstract Objective To evaluate the utility of determining the presence/absence of nasal bone in a low‐risk fetal population. Methods Prospective study of the presence/absence of nasal bone among 1800 consecutive unselected fetuses, with complete follow‐up of results. Results An adequate sonographic evaluation of nasal bone was obtained in 1682 (93.44%) of the fetuses. Nasal bone was considered absent in 19 (1.06%) of 1790 fetuses with a normal karyotype and in 2 (28.57%) of the seven recorded cases of Down syndrome (DS). The overall first‐trimester sensitivity for DS to the absence of nasal bone was two of the six cases (33.3%) and the false‐positive rate was 1.13%. The positive predictive value for DS of the absence of nasal bone was 2/21 (9.52%). Conclusions In a low‐risk population, the evaluation of the presence/absence of nasal bone in DS screening during the first trimester has a low sensitivity. First‐trimester assessment of the nasal bone in population screening may play a lesser role than in the re‐evaluation of high‐risk pregnancies. Copyright © 2006 John Wiley & Sons, Ltd.