超声NT指标联合血清生化指标在孕11～13^(+6)周孕妇21、18-三体综合征产前诊断中的价值

Value of ultrasound NT combined with serum biochemical markers in prenatal diagnosis of trisomy 21 syndrome and trisomy 18 syndrome during 11-13^(+6) gestational weeks

目的探讨超声NT指标联合血清生化指标在孕11~13^(+6)周孕妇21、18-三体综合征产前诊断中的价值。方法2015年1月-2016年1月进行产前筛查的孕早期单胎孕妇5627例,采用超声仪测定胎儿颈项透明层厚度(NT),并检测母血清中的绒毛膜促性腺激素β亚基(β-h CG)和妊娠相关血浆蛋白(PAPP-A)水平,评价超声NT指标联合血清生化指标对21、18-三体综合征的筛查效果。结果联合筛查孕妇5 627例,随访成功3 218例,共确诊胎儿染色体异常25例,其中21-三体综合征19例,18-三体综合征6例。正常核型胎儿组NT厚度和母血清中PAPP-A水平显著低于染色体异常胎儿组,β-h CG水平显著高于染色体异常胎儿组,差异均有统计学意义(P<0.05);超声NT指标联合血清生化指标筛查灵敏度明显高于单一指标筛查,假阳性率低于单一指标筛查,差异均有统计学意义(P<0.05);联合筛查高风险组妊娠结局异常率显著高于筛查低风险组,差异有统计学意义(P<0.01)。结论超声NT指标联合血清生化指标筛查孕11~13^(+6)周孕妇21、18-三体综合征,其灵敏度高、特异度好、假阳性率低,具有较高的诊断价值。

Objective To explore the value of ultrasound NT combined with serum biochemical markers in prenatal diagnosis of trisomy21 syndrome and trisomy 18 syndrome during 11- 13^＋6gestational weeks. Methods A total of 5 627 monotocous pregnant women receiving prenatal screening during the first trimester of pregnancy from January 2015 to January 2016,ultrasound was used to measure fetal nuchal translucency（ NT）,the levels of maternal serum human chorionic gonadotropin β subunit（ β- h CG） and pregnancy- associated plasma protein（ PAPP- A） were detected,the screening effect of NT combined with serum biochemical indexes for trisomy 21 syndrome and trisomy 18 syndrome were evaluated. Results A total of 5 627 pregnant women were screened,and 3 218 pregnant women were followed up successfully,25 cases were definitely diagnosed as fetal chromosomal abnormalities,including 19 cases with trisomy 21 syndrome and 6 cases with trisomy 18 syndrome. NT thickness and maternal serum PAPP- A level in normal karyotype fetus group were statistically significantly lower than those in fetal chromosomal abnormality group（ P〈0. 05）; maternal serum β- h CG level in normal karyotype fetus group was statistically significantly higher than that in fetal chromosomal abnormality group（ P〈0. 05）. The sensitivity of NT combined with serum biochemical indexes was higher than those of a single index screening,the false positive rate was lower than those of a single index screening,there were statistically significant differences（ P〈0. 05）; the rate of abnormal pregnancy outcome in combined screening high- risk group was statistically significantly higher than that in combined screening low- risk group（ P 〈0. 01）. Conclusion Ultrasound NT combined with serum biochemical markers in prenatal diagnosis of trisomy 21 syndrome and trisomy 18 syndrome during 11- 13^（＋6）gestational weeks has the advantages of high sensitivity and specificity and low false positive rate,which has high diagnostic value.