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Normal ranges for fetal nasal bone length determined by ultrasound at 18-20 weeks of gestation in a multiethnic Australian population.
- Source :
- Australian & New Zealand Journal of Obstetrics & Gynaecology; Aug2011, Vol. 51 Issue 4, p347-352, 6p, 1 Chart, 2 Graphs
- Publication Year :
- 2011
-
Abstract
- Objective: Absence or hypoplasia of the nasal bone is commonly reported in Down syndrome fetuses. We define normal ranges and the 2.5th centile for fetal nasal bone length (NBL) in a multiethnic Australian population at 18-20 weeks of gestation. Methods: A prospective cohort study of women attending for a routine anomaly scan. Ethnicity of the patient and their partner was recorded, and the nasal bone was measured three times. Two methods of nasal bone assessment were used to define normal ranges: a single (first) measurement and the mean value of three measurements. Mixed-effects regression models were employed to account for interoperator differences treating sonographers as random effects. Nonparametric methods were used to define the 2.5th centile for gestational age. Results: A total of 1199 women were included with a mean gestational age 19.1 (SD 0.4; range 18-20) weeks. There is significant linear relationship between NBL and gestational age ( P < 0.001). The mean of three nasal bone measurements had a smaller standard deviation than single nasal bone measurements. Nonparametric assessment was used to define the 2.5th centile, which is 4.4 mm at 18 weeks and 5.0 mm at 20 weeks of gestation. Conclusions: This study provides a reference range for fetal NBL at 18-20 weeks of gestation in an unselected multiethnic Australian population. Whilst NBL increases linearly from 18 to 20 weeks, the data are not normally distributed and nonparametric techniques are required to define the 2.5th centile. The mixed-effects model also accounts for variation in sonographer measurements. [ABSTRACT FROM AUTHOR]
- Subjects :
- ANTHROPOMETRY
ANALYSIS of variance
ASIANS
COMPUTER software
CONFIDENCE intervals
STATISTICAL correlation
ETHNIC groups
FETAL ultrasonic imaging
GESTATIONAL age
LONGITUDINAL method
NASAL bone
NONPARAMETRIC statistics
SECOND trimester of pregnancy
REFERENCE values
REGRESSION analysis
STATISTICS
WHITE people
DATA analysis
CROSS-sectional method
FETUS
ANATOMY
Subjects
Details
- Language :
- English
- ISSN :
- 00048666
- Volume :
- 51
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Australian & New Zealand Journal of Obstetrics & Gynaecology
- Publication Type :
- Academic Journal
- Accession number :
- 64856388
- Full Text :
- https://doi.org/10.1111/j.1479-828X.2011.01315.x