用于评估孕中期唐氏综合征风险的孕周标准化颈部透明带厚度值。

Gestational age standardized nuchal thickness values for estimating mid-trimester Down's syndrome risk.

作者信息

Bahado-Singh R O, Oz U A, Kovanci E, Deren O, Feather M, Hsu C D, Copel J A, Mahoney M J

机构信息

Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut 06520-8063, USA.

出版信息

J Matern Fetal Med. 1999 Mar-Apr;8(2):37-43. doi: 10.1002/(SICI)1520-6661(199903/04)8:2<37::AID-MFM1>3.0.CO;2-P.

DOI:10.1002/(SICI)1520-6661(199903/04)8:2<37::AID-MFM1>3.0.CO;2-P

PMID:10090488

Abstract

OBJECTIVE

Our aim was to develop gestational age standardized indices of fetal nuchal thickening. In addition, we wanted to develop a method for combining nuchal thickness data with maternal age for calculating individual Down's syndrome risk.

METHODS

Nuchal thickness was measured prospectively in pregnancies undergoing genetic amniocentesis. A regression equation for expected median nuchal thickness based on the biparietal diameter (BPD) was developed. Nuchal thickness values were expressed as multiples of the median (MoM). Additionally, a new parameter, percentage increase in nuchal thickness (PIN) (measured minus expected nuchal thickness) X100/expected nuchal thickness, was used. Receiver operator characteristics curves for Down's syndrome detection based on nuchal thickness values expressed as MoM, PIN, and in mm were compared. Log10 transformation of MoM data resulted in a Gaussian distribution, and the Down's syndrome likelihood ratios were calculated based on the heights of the Gaussian curves. Likelihood ratios were also calculated based on PIN values. The screening efficiency of maternal age alone was compared to age plus MoM, and age plus PIN values by multiplying age-related risk by the likelihood ratio corresponding to the given nuchal thickness MoM or PIN values.

RESULTS

There were 3,574 chromosomally normal and 50 Down's syndrome fetuses in the study. Both PIN and MoM values for nuchal thickness were closely correlated (R = 1.00, P<0.001) and each was poorly correlated with gestational age (R = 0.018, P = 0.28). The Down's syndrome screening efficiency of PIN, MoM, and nuchal thickness values in mm were not significantly different. The addition of nuchal thickness data to maternal age-related risk significantly improved the Down's syndrome screening efficiency: Area under the ROC curve for maternal age risk = 0.58, maternal age + PIN area = 0.79 (P<0.001 compared to maternal age alone) and for maternal age + MoM = 0.77 (P<0.005 compared to maternal age alone).

CONCLUSIONS

The development of gestational age standardized nuchal thickness indices makes it possible to combine ultrasound and maternal age-related risk to derive individual Down's syndrome odds.

摘要

目的

我们的目标是制定胎儿颈部透明带厚度的孕周标准化指数。此外，我们希望开发一种方法，将颈部透明带厚度数据与孕妇年龄相结合，以计算个体唐氏综合征风险。

方法

对接受遗传羊膜穿刺术的孕妇进行前瞻性颈部透明带厚度测量。基于双顶径（BPD）建立了预期颈部透明带厚度中位数的回归方程。颈部透明带厚度值以中位数倍数（MoM）表示。此外，还使用了一个新参数，颈部透明带厚度增加百分比（PIN），即（测量值减去预期颈部透明带厚度）×100/预期颈部透明带厚度。比较了基于以MoM、PIN表示以及以毫米为单位的颈部透明带厚度值进行唐氏综合征检测的受试者操作特征曲线。对MoM数据进行对数10转换后呈高斯分布，并根据高斯曲线的高度计算唐氏综合征似然比。还根据PIN值计算似然比。通过将年龄相关风险乘以对应给定颈部透明带厚度MoM或PIN值的似然比，比较了单独孕妇年龄的筛查效率与年龄加MoM以及年龄加PIN值的筛查效率。

结果

该研究中有3574例染色体正常胎儿和50例唐氏综合征胎儿。颈部透明带厚度的PIN值和MoM值密切相关（R = 1.00，P<0.001），且两者与孕周的相关性均较差（R = 0.018，P = 0.28）。PIN、MoM以及以毫米为单位的颈部透明带厚度值在唐氏综合征筛查效率方面无显著差异。将颈部透明带厚度数据添加到与孕妇年龄相关的风险中，显著提高了唐氏综合征筛查效率：孕妇年龄风险的ROC曲线下面积 = 0.58，孕妇年龄 + PIN面积 = 0.79（与单独孕妇年龄相比，P<0.001），孕妇年龄 + MoM = 0.77（与单独孕妇年龄相比，P<0.005）。