21-三体综合征妊娠早期联合筛查模式的评估

目的：评估妊娠早期联合筛查21-三体综合征模式的质量。方法：入选者为500例妊娠11～13＋6周进行产前筛查的妊娠妇女，超声检测胎儿颈项透明层（nuchal translucency，NT）厚度，同时取妊娠妇女静脉血，以时间分辨法检测血清中游离人绒毛膜促性腺激素亚单位（β-hCG）及妊娠相关蛋白A（PAPP-A）水平，并根据患者年龄、体质量、种族、吸烟史、妊娠方式、妊娠周数等转化成该指标的中位数倍数（MoM），风险值为1∶270，联合评估妊娠妇女21-三体综合征的患病风险，记录实施产前诊断妊娠妇女胎儿的染色体核型。所有妊娠妇女均进行妊娠期监测及产后随访，将妊娠妇女及胎儿结局输入数据库。最后对妊娠早期时的筛查模式及筛查质量进行评估。结果：①500例中有6例为21-三体高风险（行产前诊断5例），其中3例在产前诊断时确诊。另有40例为年龄高风险（＞35岁），其中5例行产前诊断，均为正常核型胎儿。②在妊娠早期，非21-三体核型胎儿的NT厚度随其顶臀长（CRL）增加而增加。③正常胎儿母亲血清PAPP-A水平随妊娠周增加而增加，β-hCG水平随妊娠周增加而下降。结论：①单独年龄高风险不应作为产前诊断的指标。②NT厚度与妊娠周相关，应进行多中心大样本研究，并根据不同妊娠周建立适合中国人群的NT诊断标准。③妊娠早期筛查应在有超声NT测量资质的医院进行，且最好在妊娠12周时进行。④妊娠早期母亲血清PAPP-A及β-hCG水平变化与妊娠周有关。

Screening for Trisomy 21 at 11-13+6 Weeks of Gestation

Objective:To investigate the performance of first trimster screening for aneuploidies in the combined test of maternal age,fetal translucency thickness and serum free β-human chorionic gonadotropin(β-hCG) and pregnancy-associated plasma protein-A(PAPP-A).Methods:Screening with the combined test at 11 to 13+6 weeks of gestation was performed in singleton pregnancies,including 497 euploid fetues and 3 trisomy 21syndrome.The blood test and ultrasound scan were carried out in the same visit.The measure free β-hCG and PAPP-A were converted into a multiple of the median(MoM) for gestational age,adjusted for maternal weight,ethnicity,smoking status,method of conception.Results:① 500 cases of pregnant women in early screening of trisomy 21 and 6 high-risk people,of which 3 were confirmed by prenatal diagnosis.Another 40 were age high-risk,5 of whom were normal.② NT thickness count on the CRL.③Serum PAPP-A levels ascend and free β-hCG of the maternal unaffected decrease with pregnant weeks increasing.Conclusions:①The high risk of ages can not be a rule in invasive prenatal diagnosis.②The NT dependant on the CRL,and we should perform multicenter study to find the NT standard of chinese pepole.③NT screening should be measured in a qualified hospital,and preferably 12 weeks of gestation.④The maternal serum level of PAPP-A and free β-hCG relate with the pregnant weeks.