血清学、系统超声及其联合应用在产前三种出生缺陷筛查中的效能比较研究

A comparative study of serological effectiveness,system of ultrasonic and combined screening in prenatal screening of three kinds of birth defects

目的比较单一血清学筛查、单一系统超声筛查及血清学联合系统超声在孕中期筛查以唐氏综合征、18-三体综合征为主的染色体疾病中的效能,以期通过规范化的产前筛查减少出生缺陷的发生,同时为产前筛查的有效实施提供科学依据。方法收集2013年6月至2015年6月进行产前血清学筛查的单胎孕妇38 165例,于孕15~20周,抽取孕妇空腹静脉血2 ml,测定血清中甲胎蛋白（AFP）、游离人绒毛膜促性腺激素（f HCG）和（或）游离雌三醇（u E3）浓度。根据随机配载的筛查软件计算出孕妇孕育唐氏综合征、18-三体综合征和神经管畸形胎儿的风险值,唐氏综合征、18-三体筛查高风险孕妇知情同意行羊膜腔穿刺羊水细胞培养核型分析。将孕15~28周行系统超声筛查的10 727例结果纳入研究,胎儿结构异常者为超声筛查高危,筛查高危孕妇知情同意后行进一步确诊。结果血清学筛查提示唐氏综合征或18-三体综合征高风险且愿意接受羊膜腔穿刺者1 708例,确诊胎儿核型异常69例,异常核型检出率为4.0%。其中非整倍体共38例,包括唐氏综合征25例,18-三体8例;染色体结构畸变31例。10 727例孕期超声,先天结构异常236例,检出率为2.2%。超声筛查高危并接受羊膜腔穿刺、羊水细胞培养核型分析者共170例,胎儿核型异常的阳性率达到28.8%（49/170）。血清学筛查与系统超声筛查相结合,两者之一筛查高危并接受羊水细胞核型分析者共1 819例,异常核型阳性率为5.7%（103/1 819）。与单一血清学筛查比较差异并无统计学意义,而血清学筛查与超声筛查均提示为高危者共59例,检出胎儿核型异常15例,异常核型阳性率为25.4%,显著高于单一血清学筛查,但与单一系统超声筛查效能比较无统计学差异。结论孕中期行血清学筛查,是筛查胎儿神经管畸形,筛查以唐氏综合征、18-三体综合征为主的染色体疾病的有效方法之一。系统超声筛查效能高于单一血清学筛查,联合筛查效能高于单一血清学筛查,以血清学筛查为基础,联合超声筛查,可以提高产前筛查准确率。中孕期系统超声筛查能诊断大部分胎儿结构畸形,降低出生缺陷。同时超声筛查发现的一些结构异常可以提示胎儿染色体异常,中孕期超声筛查对于18-三体有较高的提示作用。

Objective To compare the efficiency of serum screening, ultrasound screening and the combination of both in the screening of chromosomal disorders including Down syndrome and trisomy 18 , in order to reduce the incidence of birth defects, as well as to provide a scientificfoundation for the effective implementation of prenatal screening. Methods 38 165 singleton pregnancies between 15 and 20 weeks ＂gestation whocarried out prenatal screening during November 2013 to November 2014 were retrospectively studied. 2 ml of venous blood were used to detect theconcentration of free p - human chorionic gonadotropin （fHCG） , a - fetoprotein （ AFP） and / or estriol （ uE3 ）. The risk value of Down s syndrome, trisomy 18 syndrome and neural tube defects were caculated by using algorithms, and Pregnancies with high risk of Downs syndrome or trisomy18 who signed informed consent would underwent karyotypeanalysis. 10 727 cases who performed ultrasound screening between 15 and28weeks＂gestation were included in the study. Fetuses who were detected with abnormal ultrasound findings were considered screening positive. Allutrasonography screening positive women who signed informed would underwent prenatal diagnose. Results There were 1 708 women acceptedprenatal diagnose who were Down syndrome and trisomy 18 screen - positive, 69 cases with abnormal fetal karyotype were found with the abnormalrate of 4. 0% , among which there were 38 cases with aneuploid, including 25 cases of 21 trisomy, 8 cases of trisomy 18 , and chromosome structuralaberrations of 31 cases. Among 10 727 cases with ultrasound screening, 236 fetues were found congenital structural abnormality and detectionrate was 2. 2% . 170 fetuses who were detected with abnormal ultrasound findings accepted fetal chromosome karyotypes analysis, means abnormalfetal karyotype positive rate was 28. 8% （49/170）. When combined maternal serum screening with ultrasound, one of them screen - positive andunderwent prenatal diagnose had 1819 cases, the abnormal rate was 5. 7% （103/1 819）. While it was identified 59 cases of abnormal fetal karyotypein which the mother had undergone both a serum screen and a second trimester ultrasound, the karyotype abnormal rate was 25.4% , the rateof detection significantly higher than only maternal serum screening, but there were no significant differences with ultrasound. Conclusion Secondtrimester maternal serum screening is an effective method of screening for fetal neural tube defects, trisomy 21 , trisomy 18 and other chromosomaldisorders, pregnancies who screen - positive underwent further confirmed, can reduce the incidence of birth defects. It has important socialand economic benefits. The performance of ultrasound sreening and the combination of ultrasound and maternal serum screening are better thansimple maternal serum screening, when combine the two together, it can increase the accuracy. Second trimester ultrasound screening can diagnosemost of the structural malformations, reduced birth defects. At the same time, fetal structure abnormalities are the effective ultrasound indicator forfetus chromosomal abnormalities, and second trimester ultrasound screening is effective in detecting fetus with trisomy 18.