无创产前筛查低风险人群中超声软指标阳性的临床意义

Clinical significance of positive ultrasound soft markers in non-invasive prenatal tseting of low-risk population

目的 探讨无创产前筛查(NIPT)低风险人群中超声软指标阳性与胎儿染色体异常的关系,并分析其临床应用价值。方法 回顾性分析2012—2021年因孕中期超声检查发现胎儿存在超声软指标阳性并在河北省人民医院行介入性产前诊断的单胎妊娠3 856例孕妇的临床资料,根据是否行NIPT将纳入人群分为A组和B两组;A组为未行NIPT组,共3 311例;B组为行NIPT提示低风险组,共545例。比较两组间各项超声软指标中染色体异常的检出情况。结果 2012—2021年共有3 856例单胎妊娠孕妇因超声软指标阳性行介入性产前诊断,经确诊染色体异常胎儿124例,总检出率约为3.22%。各项软指标中,以2项及以上软指标异常的案例染色体异常检出率最高,为8.27%(47/568),明显高于总检出率,其中目标三体比例最多(74.47%,35/47);其次,孤立性单脐动脉和轻度肾盂扩张的检出率(0.78%、1.46%)均明显低于总检出率,差异均有统计学意义(χ^(2)=4.759、4.525,均P<0.05)。B组21-三体综合征(0.00%)、18-三体综合征(0.00%)及染色体异常总检出率(0.37%)均明显低于A组(2.29%、0.75%及3.68%),差异均有统计学意义(χ^(2)=12.761、7.646及16.550,均P<0.05)。B组中孤立性肠管回声增强和2项及以上阳性软指标各发现1例性染色体异常胎儿,其余各项孤立性软指标均未发现染色体异常胎儿。结论 染色体异常胎儿中检出超声软指标阳性的多为21-三体综合征和18-三体综合征胎儿,NIPT低风险可降低因超声软指标阳性提示胎儿可能存在染色体异常的比例,因此对该类孕妇行介入性产前诊断值得思考,应充分权衡胎儿丢失的风险和给孕妇及其家庭带来的焦虑。

Objective To explore the relationship between ultrasound soft markers and fetal chromosomal abnormalities in low-risk population of non-invasive prenatal testing(NIPT),and analyze its clinical value.Methods The clinical data of 3856 pregnant women with singleton pregnancies who underwent interventional prenatal diagnosis in Hebei General Hospital from 2012 to 2021 due to the fetal positive soft markers detected by ultrasound in the second trimester of pregnancy were analyzed retrospectively.According to the pregnant women whether inspected by NIPT or not,the includ populations were divided into Group A and B:Group A was treated without NIPT,total 3311 cases;Group B was treated with NIPT and suggested low risk,total 545 cases.The detection of chromosomal abnormalities in various ultrasound soft markers was compared between the two groups.Results From 2012 to 2021,3856 pregnant women with single pregnancy underwent interventional prenatal diagnosis due to positive ultrasound soft markers,and 124 fetuses with chromosome abnormality were diagnosed,the total detection rate was about 3.22%.Among all soft markers,the cases with two or more abnormal soft markers had the highest detection rate of chromosome abnormality,which was 8.27%(47/568),significantly higher than the total detection rate,and the target trisomy ratio was the most(74.47%,35/47).Following,the detection rates of isolated single umbilical artery and mild dilated renal pelvis were significantly lower than the total detection rate(0.78%,1.46%),the difference were statistically significant(χ^(2)=4.759,4.525,all P<0.05).In group B,the 21-trisomy syndrome(0.00%),18-trisomy syndrome(0.00%)and the total detection rate of chromosome abnormality(0.37%)were significantly lower than those in group A(2.29%,0.75%and 3.68%),the differences were statistically significant(χ^(2)=12.761,7.646 and 16.550,all P<0.05).In group B,one fetus with abnormal chromosome was found in isolated intestinal echo enhancement and two or more positive soft markers,and no fetus with abnormal chromosome was found in other isolated soft markers.Conclusion The 21-trisomy syndrome and 18-trisomy syndrome are the most frequently detected soft markers in fetuses with chromosomal abnormalities.The low risk of NIPT can reduce the proportion of fetuses with chromosomal abnormalities due to ultrasound soft markers.Therefore,interventional prenatal diagnosis for this type of pregnant women should be considered,and the risk of fetal loss and anxiety bring to pregnant women and families should be fully weighed.