3657例孕中期唐氏筛查及产前诊断的临床价值分析

The Clinical Value Analysis of Second Trimester Prenatal Screening and Diagnosis of 3657 Cases of Down's Syndrome

目的探讨孕中期唐氏筛查对检出胎儿染色体异常和妊娠不良结局的临床价值。方法应用时间分辨荧光免疫法对3657例孕中期(14～20+6周)妇女进行血清标记物AFP和free-β-hCG2项指标双标记检测。筛查结果应用LifeCycle和Elipse软件计算唐氏综合征风险。唐氏筛查风险切割值为1∶270,当切割值≥1∶270时为唐氏高危孕妇。对于高危孕妇,于孕18～22周左右进行羊膜腔穿刺,抽取羊水进行胎儿染色体核型分析。并继续追踪胎儿和孕妇情况。结果在有回访资料的3258例孕妇中,去筛查到高危212例,唐氏筛查阳性率为5.8%(212/3657)。其中68例接受羊水或脐血穿刺产前诊断,占筛查高危孕妇的32.1%(68/212);发现胎儿染色体异常8例,异常检出率11.8%(8/68),其中3例唐氏综合征、2例18-三体综合征、1例Turner’s综合征、1例9号染色体臂间倒位、1例平衡易位。唐氏筛查高风险和低风险组不良妊娠结局分别为6.6%和3.4%,呈显著性差异(p<0.05)。结论孕中期产前筛查是预测异常胎儿和不良妊娠结局的有效指标。结合羊水培养或脐血培养等产前诊断技术和方法,对预防先天缺陷儿出生有重要临床应用价值。

Objective To investigate the clinical value of second trimester Down's syndrome screening on detection of fetal chromosomal abnormalities and adverse pregnancy outcome. Methods Applicate time-resolved fluorescence immunoassay on 3 657 cases of second trimester (14-20+6 weeks) women with two targets double-labeled testing of serum markers AFP and free-β-hCG. Applicate LifeCycle and Elipse to calculate Down's syndrome risk with the risk cutting value of 1:270,which ≥1:270 is high-risk pregnant women for Down's syndrome.For these pregnant women,use Amniocentesis at 18-22weeks to conduct fetal karyotype analysis and continue to track the fetal and maternal outcomes.Results There were 212 cases of high-risk pregnant women of 3258 cases pregnancty women which have follow up and Down's syndrome positive rate of screening 5.8% (212/3657). We found 8 cases fetal chromosome abnormalities within 68 women (11.8%,8/68) who received prenatal diagnosis of amniotic fluid or umbilical cord puncture (32.1%,68/212). Of the 8 fetal chromosome abnormalities,there were 3 cases of Down's syndrome,2 cases of 18-trisomy,1 case of Turner's syndrome,1 case of chromosome 9 pericentric inversion and 1 case of balanced translocation. Down's screening rate of high risk and low risk of adverse pregnancy outcomes were 6.6% and 3.4%,showing significant difference (p <0.05).Conclusion Second trimester prenatal screening is an effective indicators for predicting abnormal fetal and adverse pregnancy outcomes. Combination of umbilical cord blood and amniotic fluid culture or the cultivation of prenatal diagnostic techniques and methods to prevent birth defects in children born has an important clinical value.