妊娠相关血浆蛋白A筛查胎儿染色体病的灵敏度和假阳性率研究

目的 分析妊娠相关血浆蛋白A（PAPP－A）在产前筛查胎儿染色体病时的灵敏度和假阳性。方法 测定1372例妊娠7－32周的孕妇血清PAPP－A水平，其中99例于孕期抽取脐静脉血、羊水或胎儿出生后的外周血确定胎儿染色体核型。结果 99例中染色体核型异常的20例，正常的79例；以PAPP－A≤0．33MoM，≤0．35MoM，≤0．43MoM，≤0．60MoM，≤0．85MoM为诊断界点，灵敏度分别为75％，80％，85％，90％，95％，假阳性率分别12％，13％，17％，27％，43％。结论 孕期取PAPP－A≤0．43MoM为诊断界点可筛查出约85％的染色体病胎儿。

Study on sensitivity and false-positive rate of serum pregnancy associated plasma protein A(PAPP-A) screening for abnormal fetal karyotype

Objective To determine the sensitivity and false-positive rate of maternal serum pregnancy associated plasma protein A(PAPP-A) screening for abnormal fetal karyotype. Methods Serum PAPP-A from 1372 pregnancies at 7 to 32 weeks of gestation were measured by ELISA. The karyotype of umbilical cord blood, amniotic fluid or neonatal peripheral blood were determined by cytogenetic analysis in 99 cases. Results 79 women had a pregnancy with normal karyotype. The karyotypes were abnormal in 20 pregnancies. PAPP-A at the cut off points less than 0 33 multiples of the median(MoM), 0 35 MoM, 0 43 MoM, 0 60 MoM and 0 85 MoM had chromosome abnormality detection retes of 75%, 80%, 85%, 90% and 95%, respectively. The false-positive rates of PAPP-A screening at these cut off points were 12%, 13%, 17%, 27% and 43%, respectively. Conclusion Screening by PAPP-A at the cut off level of 0 43 MoM can detect 85% of cases with abnormal karyotype with a false-positive rate of 17%.