PT/NBL ratio assessment at mid-trimester in prenatal screening for Down syndrome in a Chinese population. (December 2014)

• Record Type: Journal Article
• Authors: Yang, Xin; Zhen, Li; Pan, Min; Han, Jin; Li, Dongzhi; Liao, Can
• Is Part Of: Journal of maternal-fetal & neonatal medicine. Volume 27:Number 18(2014)
• Page Start: 1860
• Page End: 1863
• Publication Date: 2014-12
• Subjects: Obstetrics -- Periodicals; Perinatology -- Periodicals; Infants (Newborn) -- Diseases -- Periodicals; Neonatology -- Periodicals; 618.2
• DOI: 10.3109/14767058.2014.885944
• Languages: English
• ISSNs: 1476-7058

Abstract

<abstract> <title>Abstract</title> <p> <italic>Objective</italic>: To investigate the ratio of prenasal thickness (PT) to nasal bone length (NBL) in normal and trisomy 21 fetuses in the second and third trimester in Chinese population.</p> <p> <italic>Methods</italic>: The NBL and PT were measured blindly by using 3D volumes in 143 normal fetuses and 31 trisomy 21 fetuses.</p> <p> <italic>Results</italic>: The mean PT (<italic>r</italic> = 0.83, <italic>p</italic> = 0.004) and NBL (<italic>r</italic> = 0.87, <italic>p</italic> = 0.0062) both increased with the gestation age, while the PT/NBL ratio (<italic>r</italic> = 0.12, <italic>p</italic> &gt; 0.10) remained stable. There was significant difference between normal and trisomy 21 fetuses (<italic>p</italic> &lt; 0.001). If we took the 95th of the normal fetuses as the cut-off value, the detection rate was only 46%. By using ROC curve to evaluate the screening value of PT/NBL ratio, the area under receiver operating characteristic (ROC) curve was 0.88 (95% confidence interval 0.81 to 0.94, <italic>p</italic> &lt; 0.0001).</p> <p> <italic>Conclusions</italic>: In Chinese population, the PT/NBL ratio is not a very strong ultrasound marker to predict trisomy 21 fetuses. However, it can be used as an ultrasound marker for Down syndrome screening during the second and third trimester of pregnancy.</p> </abstract>