孕中期唐氏综合征筛查及产前诊断

目的 :探讨唐氏筛查及产前诊断在预防和减少染色体病及先天缺陷儿出生的实用价值。方法 :应用时间分辨荧光免疫法对孕中期 (15～ 2 0周 )妇女进行血清标记物 (AFP+Free-β- HCG)二项指标双标试剂盒检测 ,筛查结果应用 Multicalc软件计算唐氏综合征风险。唐氏综合征 (Down's Syndrome,DS)风险切割值为 1∶ 2 74 ,当≥ 1∶ 2 74时为 DS高危孕妇 ,结合 B超、羊水或胎血进行诊断排除胎儿异常。结果 :产前筛查 36 85例孕妇 ,筛查 DS高危孕妇 2 2 0例 ,阳性率为 5 .97% ,有 118例接受了羊水或胎血产前诊断 ,发现胎儿染色体异常 11例 ,异常检出率为 9.32 % ,DS筛查 NTD高危 4 5例 ,阳性率为 1.2 2 %。在高危孕妇中 B超发现异常胎儿 10例。结论 :孕中期血清 AFP和 Free-β- HCG标记物是产前筛查异常胎儿的有效指标 ,再结合羊水或胎血、B超产前诊断对防止先天缺陷有实用性价值。

Down's syndrome screening and antenatal diagnosis in the pregnant metaphase

? Objective:To explore the practical value of Down's screening and antenatal diagnosis in preventing and decreasing chromosomal disease and congenital birth defect. Methods: Serum AFP and free-β-HCG level of pregnant women (15~20 weeks) were detected by time-distinguished fluorescence immunoassay. Down's syndrome risk value was calculated with Multicalc software, its cut-off value was 1:274. The pregnant women whose value are higher than or equal to 1:274 would be at high risk and need to exclude fetal abnormal karyotype combing diagnoses with ultrasonic B examination, amniocentesis or fetal blood. Results:3 685 pregnant women accepted antenatal screening, 220 cases of them were detected at high risk with Down's syndrome, and positive rate was 1.22%. Of 118 cases diagnosed by amniocentesis or fetal blood, 11 cases with fetal abnormal chromosome, the detectable rate was 9.32%; 45 cases at high risk of Down's syndrome, the positive rate was 1.22%. In the high-risk pregnant women, 10 cases with abnormal fetal were found by ultrasonic B. Conclusion:Serum AFP and free-β-HCG level of pregnant women were effective indexes to screen abnormal fetal combining with antenatal screening of amniotic, fetal blood or ultrasonic B, which would be a practical method of preventing congenital defect. 〔