【摘要】 目的　探讨孕妇血清 β 绒毛膜促性腺激素 ( β HCG)在产前筛查非整倍体胎儿的最佳诊断界点。 方法　分析 1999年 5月至 2 0 0 2年 12月 36 30例孕妇血清 β HCG水平及其胎儿染色体核型 ,计算 β HCG不同诊断界点时筛查非整倍体胎儿的灵敏度及假阳性率。结果　 18例中 11例非整倍体胎儿的母亲血清 β HCG水平高于正常孕妇 ( 6 1% ,11/ 18) ,为正常孕妇血清 β HCG中位数的 2 5 3倍 (MoM =2 5 3) ( P <0 0 5 )。单项 β HCG、单项孕妇年龄或 β HCG结合孕妇年龄进行筛查 ,以 β HCG结合孕妇年龄进行筛查的价值最高 ,单项 β HCG次之 ,单项孕妇年龄最低。以假阳性率 5 %为标准 ,β HCG的诊断界点为≥ 3 0 0MoM ,β HCG结合孕妇年龄进行筛查可检测出 5 0 %的非整倍体胎儿 ,单项 β HCG及单项孕妇年龄分别可检测出 4 5 %、34%的非整倍体胎儿。 结论　应用孕妇血清 β HCG筛查非整倍体胎儿 ,以 β HCG≥ 3 0 0MoM为诊断界点时诊断价值最高更多还原

【Abstract】 Objective To determine the best cut off level of maternal serum total β human chorionic gonadotrophin(β HCG) in screening for fetal aneuploidy.Methods From May 1999 to December 2002,maternal serum total β HCG levels and their babies’ karyotype were analyzed to calculate the sensitivity and false positive rate for screening fetal chromosomal abnormalities at different β HCG cut off points.Results The median of total β HCG in the affected pregnancies was 2 53 times of the normal median(MoM=2 53),P<0 05;61%(11/18) of affected pregnancies had total β HCG >2 00MoM.With a cut off point of ≥3 00MoM,β HCG combined with maternal age would achieve a detection rate of 50%,based on a false positive rate being 5%.Conclusion Screening for fetal aneupliody by maternal total β HCG at the optimal cut off point of ≥3 00MoM will achieve the best detection sensitivity.更多还原