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Updated: Aug 15, 2026

High Frequency Ultrasound for the Analysis of Fetal and Placental Development In Vivo
Published on: November 8, 2018
Association between first trimester absence of fetal nasal bone on ultrasound and Down syndrome
L Otaño1, H Aiello, L Igarzábal
1Division of Obstetrics and Gynecology, Hospital Italiano de Buenos Aires, Argentine. lucas.otano@hosptialitaliano.org.ar
Objectives:
To evaluate the association between absence of nasal bone on ultrasound and Down syndrome in fetuses at 11-14 weeks of pregnancy.
Methods:
One hundred and ninety-four consecutive fetuses from singleton pregnancies undergoing chorionic villi sampling (CVS) were evaluated by transabdominal ultrasound. A sagittal view of the fetal face was obtained and the absence or presence of nasal bone was recorded and correlated with the fetal karyotype.
Results:
A successful view of the fetal profile was possible in 183 of 194 (94%) fetuses. The nasal bone was absent in three of five fetuses with Down syndrome, and in one of 175 (0.6%) chromosomally normal fetuses.
Conclusion:
Absence of nasal bone by first trimester ultrasound was significantly associated with Down syndrome. When a proper view of the fetal face was obtained, the nasal bone was visible in more than 99% of karyotypically normal fetuses.
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