Fetal nasal bone length during the second trimester of pregnancy in a Turkish population

Abstract

Objective: To determine the distribution of fetal nasal bone length (NBL) according to gestational age during the second trimester of pregnancy in a Turkish population. Study design: Fetal NBL and other routine biometric measurements were evaluated retrospectively in 2327 fetuses between 15 and 24 weeks of gestation. The measurements were obtained via transabdominal ultrasound. The distribution of fetal NBL between 15 and 24 weeks of gestation was established, and percentiles were calculated. Relationships between fetal NBL and other parameters were assessed using regression analysis. Results: Mean (+/- standard deviation) fetal NBL ranged from 2.95 +/- 0.52 at 15 weeks of gestation to 6.26 +/- 0.77 mm at 24 weeks of gestation. The fifth percentile for fetal NBL was 2.1 mm at 15 weeks of gestation and 5.0 mm at 24 weeks of gestation. A significant positive correlation was noted between fetal NBL and gestational age (NBL = gestational age x 0.37-2.55; R-2 = 0.59; p < 0.01) and between fetal NBL and biparietal diameter (BPD) (NBL = BPD x 0.11-033; R-2 = 0.61; p < 0.01). Conclusion: Fetal NBL is less in Turkish subjects compared with non-Turkish subjects. (C) 2014 Elsevier Ireland Ltd. All rights reserved.