唐氏综合征孕中期产前筛查及产前诊断的临床价值

目的探讨唐氏综合征的产前筛查和产前诊断在预防出生缺陷中的价值。方法对68813例孕15-20w的孕妇采用时间分辨荧光免疫方法检测血清AFP和B-HCG浓度，通过Maiticale软件计算危险系数，对唐氏高危和18-三体高危孕妇取羊水获脐血作染色体诊断，对神经管缺陷（NTD）高危孕妇行系统超声检查。结果筛查68813例孕妇，其中2632例为唐氏综合征或18-三体综合征高分险病例，占总筛查人数的3.82%；NTD高风险542例，占0.79%。接受羊水或脐血染色体检查1772例（占总阳性数的67.32%），检出异常核型67例，占异常发生率3.78%；NTD高风险行超声检查证实胎儿畸形58例，占筛查高危孕妇的10.7%。结论孕中期产前筛查结合产前诊断可以有效预防出生缺陷的发生。

Study on Down's syndrome prenatal screening and diagnosis

Objective： To investigate the value of screening and diagnosing Down＇s syndrome for the frequency of natal defect. Methods： Autotime resolved fluoroimmunoassay system was used to detect the maternal serum AFP and free - β -HCG in 68513 pregnant women at about 15 - 20 weeks of gestation. Down＇s syndrome, NTD, Edwards syndrome risk value was calculated with Multicalc software, their cut off were 1 ： 270, 1 ： 250, 1 ： 350 separately. The pregnant women whose value are higher than or equal to cut - off would be at high risk and need to exclude fetal abnormal karyotype coming diagnoses with ultrasound examination, amniocentesis or fetal blood. Results： 68813 pregnant women accepted antenatal screening, 2632 of them were at high risk with Down＇s syndrome or trip loid syndrome, 542 case with NTD. In the high risk pregnant women, 67 case with fetal abnormal chromosome were found by amniotic fluid or fetal blood culture, 58 case with abnormal fetal were found by ultrasound. Conclusion： Prenatal screening and prenatal diagnosis have very important significance to the prevention of Down＇s syndrome and other congenital abnormality.