妊娠相关血浆蛋白A对唐氏综合征胎儿的筛查价值

目的:探讨母体血清妊娠相关血浆蛋白A(pregnancyassociatedplasmaproteinA,PAPP-A)在妊娠各期对唐氏综合征胎儿的筛查价值。方法:对3733例单胎妊娠的孕妇进行血清PAPP-A水平检测,其中对586例孕妇取羊水或脐带血检测胎儿染色体核型,5例新生儿出生后取外周血进行染色体核型检查。结果:①唐氏综合征组的孕妇血清PAPP-A<0.40MoM的占60%,中位数为0.32MoM,明显低于正常组(1.02MoM)(P=0.000);唐氏综合征组的孕妇年龄及丈夫年龄中位数均明显高于正常组(P=0.000和P=0.004)。②以PAPP-A<0.40MoM为诊断界点,假阳性率为5%。当假阳性率为5%时,单项母体血清PAPP-A、单项孕妇年龄、母体血清PAPP-A联合孕妇年龄及丈夫年龄筛查唐氏综合征胎儿的灵敏度分别为60%、50%、80%。结论:①PAPP-A联合孕妇年龄及丈夫年龄的筛查灵敏度高于单项PAPP-A。②PAPP-A在妊娠早期、中期、晚期筛查唐氏综合征胎儿均有价值。

Screening for fetuses with Down''''s syndrome by pregnancy associated plasma protein (PAPP) - A

Objective:To determine the efficacy of maternal serum pregnancy associated plasma protein A (PAPP-A) in screening for Down's syndrome pregnancies at different gestational ages.Methods:A total of 3 733 singleton pregnant women aged 18 to 51 (median 29) between 6 weeks 1 day and 36 weeks 6 days of gestation were offered screening for Down's syndrome with serum PAPP-A. 586 women underwent an invasive diagnostic procedure including amniocentesis and cordocentesis for the antenatal detection of Down's syndrome. The karyotypes of five newborn babies were detected because of retarded features or deformity.Results:⑴The median of maternal PAPP-A level in unaffected pregnancies was 1.02 MoM.The median of maternal PAPP-A level in Down's syndrome pregnancies was 0.32 MoM( 60% of cases less than 0.40 MoM,P = 0.000 ). The maternal age in Down's syndrome group was greater than that in unaffected pregnancy group(P= 0.000). The paternal age in Down's syndrome group was greater than that in unaffected pregnancy group too (P=0.004). ⑵Maternal PAPP-A, maternal PAPP-A combined with maternal age and paternal age, and maternal age would respectively detect 60%, 80% and 50% of Down's syndrome fetuses with a false positive rate of 5%.Conclusion:⑴The maternal PAPP-A combined with maternal age and paternal age would significantly improve the detection rate compared with maternal PAPP-A. ⑵ Down's syndrome can be detected by maternal serum PAPP-A at different trimester of gestation.