妊娠中期人绒毛膜促性腺激素联合甲胎蛋白筛查唐氏综合征的临床价值

To investigate the value of human chorionic gonadotropin and alpha-fetoprotein in screening for Down's syndrome

目的：探讨妊娠中期人绒毛膜促性腺激素（HCG）联合甲胎蛋白（AFP）产前筛查糖氏综合征（DS）的临床价值。方法：采用酶联免疫吸附法对孕14—20周的孕妇进行血清HCG和AFP检测，结合孕妇年龄、孕周、体重等因素，利用配套软件计算风险率，DS风险切割值1：275。筛查为高风险的孕妇进行遗传咨询，在知情同意的情况下进行羊水细胞染色体检查。每例筛查孕妇追踪到出生。结果：655例孕妇中，筛查出高危孕妇34例，在阳性孕妇中发现DS2例。本方法的灵敏度、特异度分别为为100．00％（2／2）、95．10％（621／653），假阳性率为4．90％（32／653）、无假阴性病例；阳性预测值、阴性预测值分别为5．88％（2／34）、100．00％（621／621）。结论：孕妇血清HCG联合AFP筛查DS具有经济、有效、操作简便的优点，能显著降低进行创伤性产前诊断的孕妇比例，降低DS患儿的出生率，有临床推广的应用价值。

Objective： To investigate the value of human chorionie gonadotropin and alpha - fetoprotein in screening for Down＇s syndrome. Methods： Alpha fetoprotein and beta- human chorionie gonadotropin were detected by a method based on detecting maternal serum, concentrations in the women of 14 - 20 weeks pregnancy in eombination with maternal age and gestation age. Pregnant women at risk for fetal DS were identified, by analyses of computer software, the cut point was 1： 275. Hereditary eonsultatioh was provided for the high- risk pregnant women, amnioeentesis was done with their agreement. Eaeh case was followed till the fetus Born. Results： 34 women among 655 women were screen -positive. 2 Down＇s of sereening- positive women. The detection sensitivity and specificity for Down＇s syndrome were 100% （2/2） and 95. 10% （621/653） . False - positive rate and false - negative rate were 4. 90% （32/653） and 0 （0/2） . The positive and negative predictive value were 5. 88% （2/34） and 100% （621/621） . Conclusion： The study shows that maternal serum HCG and AFP screening for fetal Downg syndrome is eeonomicalandsimpal. Prenatal screening can reduce the need for invasive prenatal diagnosis, decreasing the birth rate of DS and feasible in the clinical practice.