孕早期母血清筛查唐氏综合征

Screening of Maternal Serum for Fetal Down's Syndrome in the First Trimester

目的:用母血清生化标志物产前筛查唐氏综合征(DS).方法:用时间分辨免疫荧光分析法测定孕7～13周孕妇血清中妊娠相关血浆蛋白A(PAPP-A)和游离β-人绒毛膜促性腺激素(free β-HCG)的中位数,以及胎儿颈部透明膜厚度(NT)以确定高危人群,用T1-risk风险统计软件进行风险率计算,以1:250作为高风险的切割值,并通过绒毛染色体核型分析给予确诊.结果:359例孕妇中筛出高危个体40例,阳性率11.14%,确诊DS胎儿1例.计算出7～13孕周PAPP-A和free β-HCG中位数值.结论:在孕早期用检测PAPp-A和free p-HCG结合NT筛查DS胎儿,有望使产前诊断时间提前.

Objective Maternal serum biochemical markers were used to screen for fetal down's syndrome DS in first trimester. Methods Time-resolved immunofluorometric assay TrIFMA was used for the concentration of PAPP-A and free-β-HCG in maternal serum at 7-13 gestational week internal in order to determine the high risk persons. The risk rate was calculated with T1-risk statistical software. 1∶ 250 was regarded as the cut-off value of high risk. The fetal karotype was identified by CVS. Results In 359 pregnant women 40 samples were screened of high risk. And one was identified as DS fetus. The positive rate was 11.14%. The Medians concentration of PAPP-A and free-β-HCG at 7-13 gestational week internal was also calculated. Conclusion Screening for Down's syndrome in the first trimester is feasible and the screening time would be earlier than before.