44566例孕妇二联法血清筛查唐氏综合征胎儿分析

Study on alpha-fetoprotein and free β-human chorionic gonadotropin assays for screening Down's syndrome fetuses in 44566 pregnant women

目的了解二联法血清学产前筛查技术在中孕期妇女中筛查唐氏综合征(DS)胎儿的应用情况及效果评估。方法采用时间分辨荧光免疫法对中孕期(妊娠丨5~20+6周)妇女进行二联法血清学产前筛查,辉查为高风险(英1:270)的孕妇,采用羊膜腔穿刺、羊水细胞培养和染色体核型分析进行产前诊断,并对分娩的新生儿进行网络随访,对可疑DS的新生儿行外周血染色体核型分析诊断。结果筛查出DS髙风险1 803例,筛查阳性率为4_05%,阳性者经羊水染色体检查,蹦诊9例胎儿;在随访的34 715例筛查为低风险孕妇中确诊新生儿DS6例。共确诊15例DS患儿,产前筛查检出率为60.00%(9/15),假阳性率为4.02%(I 794/44 551),假阴性检出率0.17%(6/34 715)。血清学筛查结果为高风险者,其检出DS儿的机率高于低风隆者,两者差异有统计学意义X2=102.908,P<0.001)。结论中卒期妇女二联法血清学产前筛查技术是DS产前筛查异常胎儿的有效指标,但在随访过程中应注意筛查结果为假阴性或假阳性的解释工作。

Objective To study the application and evaluate the efficacy of combined measurement of alpha -fetoprotein （ AFP） and freeβ-human chorionic gonadotropin （β-hCG） for screening Down＇s syndrome （DS） fetuses in mid-term pregnant women.Methods Combined measurement of serum AFP and free β-hCG was used to screen second trimester pregnant women （ at 15-20 ^＋6 gestational weeks ） by the time resolved fluroimmunoassay （TRFIA）.The high risk pregnant women （≥1：270） underwent prenatal diagnosis by amniocentesis , cell culture and chromosome analysis .The newborns of them were followed up by network , and suspected newborns underwent peripheral blood chromosome analysis .Results Totally 1 803 of 44 566 pregnant women were diagnosed as high-risk of DS by prenatal screening , with the positive rate of 4.05%, in which 9 cases were diagnosed as DS by amniotic fluid chromosome examination .Six cases of DS fetuses were diagnosed among 34 715 followed-up low-risk pregnant women .There were 15 cases of DS fetuses in total .The detection rate of prenatal screening was 60.00%（9/15）, the false positive rate and false negative rate was 4.02% （1 794/44 551） and 0.17‰ （6/34 715） respectively.High-risk women screened by serologic examination had more possibilities receiving DS than the low-risk ones, and there was significant difference between them （χ^2 =102.908,P〈0.001）.Conclusion Combined measurement of AFP and free β-hCG is an effective indicator for screening DS in second trimester pregnant women .However , the explanation must be carefully carried out on the results being false positive or false negative during follow-up.