NT与游离βhCG及PAPP－A联合筛查孕早期唐氏综合征的应用

First trimester combined screening for Down＇s Syndrome with NT, Free-βhCG and PAPP-A

目的探讨孕早期利用颈项透明层厚度（NT），联合血清生化标志物游离8绒毛膜促性腺激素（Free-13hCG）、妊娠血浆相关蛋白A（PAPP－A）筛查DS敏感性。方法收集2009年3月至2010年10月嘉兴学院附属妇幼保健院早孕建卡时自愿参加产前筛查的孕妇（年龄17—45岁），共计11882例。分别于孕早期（11～13w＋6d）测定孕妇血液中Free-βhCG、PAPP—A值，超声测定NT值；对于同一个体，利用风险计算软件，比较在孕早期NT、Free．13hCG、PAPP—A联合筛查和血清学Free-13hCC、PAPP-A筛查对唐氏综合征的检出率和特异性的异同，比较二种筛查方案的敏感性。结果11882例孕妇，共发现18例DS，发生率为0．15％。联合筛查和血清学筛查的检出率分别为83．3％、72．2％，特异性为98．4％、97．3％，检出效率为7．18％、3．90％。受试者工作特征曲线（ROC）曲线分析，孕早期联合筛查ROC曲线下的面积值（AUC）为0．975（95％CI：0．943，1．007），血清学筛查AUC为0．901（95％CI：0．789，1．013）。结论孕早期联合筛查比血清学筛查DS有比较高敏感性和特异性，在相同的假阳性率情况下有较高检测率，可有效减少孕妇侵入性穿刺。

Objective To explore the sensitivity of using NT, combined with serum biochemical markers （Free-βhCG,PAPP-A） for Down＇s Syndrome screening in early stage of pregnancy. Methods Collect pregnant women aged 17 -45 years old voluntary antenatal screening in our hospital from March 2009 to October 2010, a total of 11882 cases. Serum Free-βhCC and PAPP-A were measured NT value was determined by ultrasound at 11 - 13w＋6d of gestation. Calculating combined screening （NT, Free-βhCC, PAPP-A）, and serum integrated screening （Free-beta hCG, PAPP-A） risk, respectively, using the risk calculation software for the same person. Results Early pregnancy screening was performed in 11 882 patients, 18 bad a fetus with Down＇s syndrome, a rate of 0. 15%. The detection rates of Down＇s syndrome in combined screening and serum integrated screening were 83.3% and 72. 2% respectively. The specificities were 98.4% and 97.3%0 and detection efficiency were 7. 18% , 3.90% respectively. Areas under the curve （AUCs） of first-trimester combined screening and serum integrated screening were 0. 975 （95% CI：0. 943, 1. 007 ） , 0. 901 （95% CI：O. 789, 1. 013 ） respectively. Conclusion In early stage of pregnancy, combined screening for Down＇s syndrome has higher sensitivity and specificity than serological screening, has higher detection rate in the same false-positive rate case, which can effectively reduce the pregnant women to receive invasive puncture.