Fetal nasal bone length at 11(+0)-13(+6) weeks of gestation: an evaluation of 554 consecutive cases


CLINICAL AND EXPERIMENTAL OBSTETRICS & GYNECOLOGY, vol.41, no.5, pp.556-560, 2014 (SCI-Expanded) identifier identifier identifier


Purpose of investigation: To develop a nomogram for estimating nasal bone length (NBL) at 11(+0)- 13(+6) weeks of gestation in 554 consecutive cases and to determine the value of NBL measurement in screening for chromosomal abnormalities. Materials and Methods: NBL and crown-rump length (CRL) were examined in 554 fetuses at 11(+0)-13(+6) weeks' gestation. A nomogram for NBL was developed with data from 479 healthy fetuses in which fetal profile examination was possible. Reference values, including percentiles, were calculated for each gestational age. Result: A linear correlation was noted between CRL and NBL in healthy fetuses at 11(+0)-11(+6), 12(+0)-12(+6) and 13(+0)-13(+6) weeks of gestation. Mean NBL was 2.18 +/- 0.53 mm, 2.46 +/- 0.45 mm, and 2.91 +/- 0.55 mm in healthy fetuses, for these time frames, respectively. NBL increased significantly with CRL from respective means of 2.26 +/- 0.43, 2.60 +/- 0.48, 2.77 +/- 0.43, and 3.16 +/- 0.52 mm at 45 - 54.9, 55 - 64.9, 65 - 74.9, and 75 -84 mm. Conclusion: The authors developed a NBL nomogram with data from normal, healthy Turkish fetuses at 11(+0)-13(+6) weeks of gestation. These reference ranges may prove useful in prenatal screening and diagnosis of syndromes known to be associated with nasal hypoplasia.