Bilateral nasal bone measurements in normal first trimester fetuses and fetuses with trisomy 21 by use of 3D ultrasound

Purpose: Three-dimensional ultrasound with its different display modes allows an accurate demonstration of the ossified bones of the fetal face in the first trimester. In particular, the nasal bones can be evaluated on both sides and measured separately. The aim of this study was to establish the normal range for the left and right nasal bone and to demonstrate the development of the nasal bones in cases with trisomy 21 in the first trimester. Material and method: In 200 normal fetuses and 12 fetuses with trisomy 21 the left and right nasal bone was measured in the multiplanar 3D mode after aligning the fetal he…