游离雌三醇在孕中期唐氏综合征筛查中的临床意义

Clinical signifi cances of uE3 in second-trimester screening for Down's syndrome

目的探讨游离雌三醇（unconjugated estriol，uE3）在孕中期唐氏综合征筛查中的应用价值。方法采用时间荧光分辨免疫法测定孕中期母血清中甲胎蛋白（AFP）、游离人绒毛促性腺激素β亚单位（Free-β-hCG）和游离雌三醇水平，再采用随机配套的Wallac 2T专用风险评估软件进行教据分析，比较二联（AFP、Free-β-hCG）和三联（AFP、Free-β-hCG和uE3）唐氏综合征（Down＇s Syndrome，DS）筛查的检出率和假阳性率以评价uE3在Ds筛查中的应用价值。结果通过对绍兴妇保院2010年1月～2012年12月50188例孕中期孕妇进行产前筛查，筛查阳性检出DS 19例，漏诊7例，DS发病率1／1930；以1／270为阳性截断值，Ds三联和二联筛查方案的检出率分别为73.08％、61.54%，检出率没有明显提高，统计学上无显著差异（X2=O.79，P〉0.05）：DS三联和二联的筛查假阳性率分别为2.53％和4.15％，三联假阳性率明显低于二联（X2=204.18，P〈0.01）。结论孕中期在DS二联筛查的基础上增加uE3指标，能一定程度上提高DS检出率，能明显降低假阳性率，具有广泛的应用价值。

Objective： To explore the application values of unconjugated estriol （uE3） in second-trimester screening for Down＇s Syndrome. Methods： Alpha-fetoprotein （AFP） , beta-human chorionic gonadotropin （Free-β-hCG） and uE3 levels in maternal serum samples of second-trimester were detected by the time-resloved fluoroimmunoassay. The risk rates of Down＇s syndrome （DS） was calculated by the Wallae Risks 2T software. Clinical significances were evaluated by Comparison of the detective rate and false positive rate （FPR） . Results： From January 2010 to December 2012, 50 188 pregnant women were detected for prenatal screening in second-trimester. Amongst the pregnant women, 19 fetuses with DS were detected and 7 fetuses with DS were fail for screening. The incidence rate of DS was 1/1930 in the second-trimester of Shaoxing city. When the risk of 1 in 270 as the cutoff to define a positive result of DS in triple and dual test, the detective rates of DS by two methods were 73.08% and 61.54%. There was no significance in the detective rate of DS by the methods （X2=0.79, P〉0.05） .The FPR of triple and dual test were 2.53% and 4.15%, the former was significantly lower than the latter （X2=204.68, P〈0.01. Conclusion The triple test instead of the dual test in the second-trimester screening for DS can, to a certain extent, improve the DS detection rate, can significantly reduce the false positive rate and has extensive application value.