兰州地区高龄孕妇产前筛查与产前诊断的回顾性分析

Retrospective analysis of prenatal screening and prenatal diagnosis of elderly pregnant women in Lanzhou

目的探讨无创产前基因检测(NIPT)技术在高龄孕妇产前筛查中的应用价值。方法选取甘肃省妇幼保健院2015年3月至2016年3月行产前筛查和产前诊断的高龄孕妇为研究对象,其中接受孕中期血清学筛查、NIPT及行羊水穿刺的高龄孕妇分别273例、844例和435例。按年龄将孕妇分为35~39岁年龄组和≥40岁年龄组。以羊水穿刺细胞核型分析为准,分别计算血清学筛查和NIPT的敏感度、特异度、阳性预测值、阴性预测值,并用χ2检验对不同高龄组胎儿染色体异常结果进行比较。结果血清学筛查出高风险孕妇20例,其中21-三体高风险14例(5.13%),18-三体高风险3例(1.10%),NTD高风险3例(1.10%),临界风险23例(8.42%)。NIPT检出高风险孕妇18例,其中包含产前筛查高风险者3例(21-三体2例,18三体1例),临界风险者21例。羊水穿刺细胞核型分析最终检出数目异常核型21例,其中包括21-三体10例(2.30%),18-三体4例(0.92%),其他异常7例(1.61%)。检测21-三体的灵敏度和特异度,血清学筛查分别为75%(3/4)和95.9%(259/270),NIPT分别为100.0%(7/7)和99.8%(835/837)。检测18-三体的灵敏度和特异度,血清学筛查分别为100.0%(1/1)和99.3%(270/272),NIPT均为100.0%(4/4和840/840)。两种检查方法的敏感度、特异度、阳性预测值和阴性预测值均有统计学意义(P<0.05)。结论应用NIPT对高龄孕妇进行产前筛查具有较高的敏感度和特异度,NIPT技术有望成为包括高龄孕妇在内的所有孕妇产前筛查的主要手段。

Objective:To explore the value of the application of noninvasive prenatal testing(NIPT)in prenatal screening for elderly pregnant women.Methods:The elderly pregnant women undergoing prenatal screening and prenatal diagnosis from March 2015 to March 2016 in Maternal and Child Health Care Hospital of Gansu Province were selected as object of study,and among them those receiving serological screening,NIPT and amniocentesis in pregnant metaphase were 273 cases,844 cases and 435 cases,respectively.Pregnant women were divided into 35~39 age group and 40+age group based on their age.According to the karyotype analysis of amniocentesis,to calculate the sensitivity,specificity,positive predictive value and negative predictive value of serological screening and NIPT,and results of fetus chromosome abnormalities in different elderly age groups were compared byχ2 test.Results:20 high-risk pregnant women were serologically screened out,and among them 14 cases(5.13%)were at high risk of trisomy 21;3 cases(1.10%)were at high risk of trisomy 18(1.10%);and 3 cases(1.10%)of high risk of NTD.23 cases(8.42%)at Crossover risk.18 cased of high-risk pregnant women were screened out by NIPT detection including 3 cases of high risk by prenatal screening(2 cases with trisomy 21,1 case with trisomy 18)and 21 cases with critical risk.21 cases of abnormal karyotypes were detected by Karyotype analysis of amniocentesis,including 10 cases of trisomy 21(2.30%),4 cases of trisomy 18(0.92%)and 7 cases for other abnormalities(1.61%).The sensitivity and specificity of trisomy 21 were 75%(3/4)and 95.9%(259/270)by Serological screening,and the NIPT value were 100.0%(7/7)and 99.8%(835/837),respectively.The sensitivity and specificity of trisomy 18 were 100.0%(1/1)and 99.3%(270/272)by Serological screening,and the NIPT were both 100.0%(4/4 and 840/840),respectively.The sensitivity,specificity,positive predictive value and negative predictive value of the two methods were statistically significant(P<0.05).Conclusion:The application of NIPT were highly sensitive and specific in prenatal screening of elderly pregnant women.The NIPT technique is expected to be the main means for prenatal screening of all pregnant women,including woman in advanced maternal age.