Fetal nasal bone length evaluation in second trimester pregnancies

Objective: nasal bone length of fetuses (nbl) in second trimester by measuring during routine obstetric sonography examination to determine the range of normal value for turk society. material-method: a total of 16-22 week gestational aged 250 healthy fetuses nasal bone lenght was measured with transabdominal ultrasonography. fetuses was evaluted by using transabdominal look with toshiba xario usts-770 device and 3,5 mhz convex transducer. routine second trimester obstetric examination of the fetuses were done and nbl of fetuses which sonographcally detected healty were measured. results: measurement of nbl of 16, 17, 18, 19, 20, 21 and 22 week gestational fetuses were calculated respectively as: 2.9– 4.6 mm, 3.3–5.1 mm, 3.4–7.3 mm, 4.3–6.6 mm, 4.8–7.3 mm, 4.6–7.5 mm, 5.6–7.2 mm (average of 5.4 mm ± 0.87). conclusion: nasal bone lenght of 16-22 week gestational aged fetuses were calculated as 2.9-7.5 mm. it should be considered as normal in this range. nasal bone lenght of second trimester fetuses under 2.9 mm should be evaluated for fetal anomalies.