15230例孕中期唐氏筛查产前诊断的临床应用价值

Clinical Application Value of Down's Syndrome Screening in the Prenatal Diagnosis:15230 Pregnancies in the Second Trimester

目的:探讨孕中期唐氏筛查对检出胎儿染色体异常的预测价值。方法:2008年1月至2009年10月,采用时间荧光免疫分辨法对我院15230例孕中期(15～20+6周)妇女进行血清标志物甲胎蛋白(AFP)、游离雌三醇(uE3)、绒毛膜促性腺激素(β-HCG)3项指标进行检测,对于筛查结果为高风险的孕妇于孕20～24周行羊膜腔穿刺进行胎儿羊水细胞染色体核型分析,并对唐氏筛查情况进行效果评价。结果:984例孕妇唐氏筛查为高风险,高风险率为6.46%,其中唐氏综合征阳性孕妇736例,18-三体阳性78例,神经管缺陷阳性169例。有773例高风险孕妇接受羊水穿刺,发现胎儿染色体异常29例,异常检出率为3.75%,其中唐氏综合征11例,18-三体1例,69,XXX1例。唐氏筛查的敏感性和特异性分别为92.86%和95.25%。结论:孕中期唐氏筛查是预测异常胎儿和不良妊娠结局的有效手段之一,羊水细胞核型分析在产前诊断中具有重要的实用价值。

Objective：To explore the prediction value of Down＇s syndrome screening in the second trimester of pregnancy in the detection of fetal chromosomal abnormality. Methods：Serum alpha-fetoprotein （AFP）、unconjugated estriol （u-E3） and β-HCG level in 15230 pregnant women（15～20＋6 gestational weeks）from Jan 2008 to Oct 2009 in our hospital were detected by time-distinguished fluorescence immunoassay. Amniocentesis for fetal karyotype was done between 20 to 24 gestational weeks in gravidas with high risk by screening.The effect of Down＇s syndrome screening was evaluated. Results：984 cases were detected at high risk,and the positive rate was 6.46%. In which,736 cases were positive in Down＇s syndrome,78 cases were positive in 18-trisome,and 169 cases were positive in neural tube defects. Amniocentesis was done in 773 cases at high risk,in which 29 cases with fetal abnormal chromosome,the detectable rate was 3.75%. Among them,11 cases were Down＇s syndrome,1 cases was 18-trisome and 1 cases was 69,XXX. The sensitivity and specificity of Down＇s syndrome screening was 92.86% and 95.25%,respectively. Conclusions：Down＇s syndrome screening in the second trimester of pregnancy is an effective method to predict abnormal fetus and bad pregnancy outcome. Amniocentesis for fetal karyotype is useful in prenatal diagnosis.