孕早期Down综合征(DS)的产前筛查

目的 :探讨孕早期Down综合征 (DS)的产前筛查。方法 :时间分辨荧光免疫法 (TRFIA)对孕 8～ 13周的 5 43 3例孕妇血清中 β hCG、PAPP A2两项血清标记物进行检测 ,比较分析 8例DS胎儿母血清与 184例对照病例血清中两种标记物水平。结果 :DS组母血中 β hCG、PAPP A平均值分别为 2 .3 1MoM和 0 .42MoM ,与对照组差别有显著性意义 (P <0 .0 5 ) ;β hCG、PAPP A两项指标联合筛查 ,DS的阳性检出率为 75 % ,假阳性率为8.3 5 %。结论 :孕早期 β hCG、PAPP A两联标记物筛查DS可以达到孕中期三联标记物筛查效果。

First-trimester prenatal screening for Down syndrome

Objective: To investigate the performance of first-trimester prenatal screening for Down syndrome.Methods: Maternal serum were collected from 5433 pregnant women between 8 and 13 weeks gestation,prior to having a chorionic villus sampling procedure.Free β glycoprotein sub-units of human chorionic gonadotrophin (β-hCG)?pregnancy-associated plasma protein(PAPP-A) were measured using time resolued fluorescence immunoassay(TRFIA).The levels of two markers was analyzed between 8 pregnancies women with DS and 184 control pregnancies women.Results: The levels of markers differed between affected and unaffected pregnancies sufficiently.The median free β-hCG level in affected pregnancies was 2.31 times the median level for unaffected pregnancies,and the median PAPP-A level was 0.42 times the unaffected median.The combination of the two markers estimate a women's risk of having a fetus with Down syndrome.A screening programme that used a risk cutoff level of 1∶250 would detect 75% of affected pregnancies and a 8.35% false-positive rate.Conclusion: The performance of screening using maternal serum free β-hCG and PAPP-A at first-trimester was similar to the triple test at second trimester.