Normative values of fetal nasal bone lengths of Turkish singleton pregnancies in the first trimester

Abstract

Objective: Evaluation of nasal bone improves the performance of firsttrimester screening for trisomy 21. In this retrospective study we aimed to determine normative values related to the measurement of nasal bone length of the Turkish population during the first trimester ultrasonographic fetal screening. Material and Methods:Medical records of singleton pregnancies, whose first trimester fetal screening was performed between 2004 and 2010, were evaluated retrospectively. Pregnancies with any detected/ suspicious anatomical or genetic fetal anomalies, biochemical abnormalities, increased nuchal translucency measurements, and pregnancies of artificial reproduction techniques were excluded from data analyses. Mean±standard deviation, median and percentile values of the length of nasal bone were calculated separately for 11 [0][1][2][3][4][5][6] , 12 0-6 and 13 0-6 gestational weeksResults: Nasal bone could be visualized in 99.6% of the included 1762 singleton pregnancies. In 16.5% of the cases nasal bones were only noted as present or absent. Mean maternal age was 29.67±4.50 years and mean gestational age was 12.54±0.61 weeks. Median values of nasal bone lengths were 1.7, 1.9, and 2.2 mm for 11 [0][1][2][3][4][5][6] , 12 0-6 and 13 0-6 gestational weeks respectively. Nasal bone length (NBL) increased linearly with advancing gestational age and CRL. NBL (mm) Conclusion:The present study presents normative values of nasal bone in the first trimester screening of normal singleton pregnancies of Turkish population. Nasal bone length increases with advancing gestational age and CRL. (J Turkish-German Gynecol Assoc 2011; 12: 225-8) Key words: Screening, nasal bone, pregnancy, ultrasonography, fetus Received: 11 August, 2011 Accepted: 26 September, 2011 Amaç: Birinci tirmester trizomi 21 taramas nda nazal kemik de erlendirmesi performans artt rmaktad r. Bu retrospektif çal mada Türk popülasyonundaki tekil gebeliklerde birinci trimester fetal nazal kemik ölçümlerinin gebelik haftalar na göre persentil da l mlar n n saptanmas amaçland .

Fetal Nasal Bone Length in the Period of 11 and 15 Weeks of Pregnancy in the Filipino Population

“…It was also evident that the nasal bone length in all cases was increased linearly as pregnancy advances. This result is in keeping with the result obtained by Ceciro et al [4] Cossi et al [14], Moon et al [9], Yayla et al [12], Chen et al [16], and Cusick et al [17]. Nasal bone length was also highly correlated with CRL.…”

“…It can be gleaned further that the average values for nasal bone measurements vary from one study to another. In our study, the mean NBL during the 11th to 15th weeks were relatively higher compared to previous studies undertaken [9,12,14,18]. It is essential to note therefore, based on the previous findings that race and ethnicity have an impact on fetal nasal bone length.…”

“…In the Turkish population, the median values of nasal bone lengths were 1.7 mm, 1.9 mm, and 2.2 mm for 11, 12 and 13 gestational weeks respectively. [12] In the study developed by Cossi et al [14] in a Brazilian population, the nasal bone length in all cases ranged between 1.69 mm and 2.94 mm at 11th and 15th weeks. It can be gleaned further that the average values for nasal bone measurements vary from one study to another.…”

“…In the current study, the mean nasal bone length ranged from 1.97 mm to 4.05 mm. When compared with other ethnic groups [9,10,12,14], nasal bone length in Filipino population appears to be longer. For instance, in the Korean population, the average nasal bone length were 1.5 mm and 2.1 mm for 11 and 14 weeks gestation [9] The NBLs at the 50th percentile in Latin American population were 1.5, 1.7, and 1.9 mm at 11, 12, and 13 weeks of gestation, respectively.…”

“…Reference values for nasal bone length have been reported in different countries and ethnic populations [9,10,11,12,14,18]. However, to the authors' knowledge, no study ascertaining reference ranges for the nasal bone length in a Filipino population have been carried out.…”