Objective: To evaluate the effect of noninvasive prenatal testing (NIPT) as first-line screening in fetal chromosome aneuploidy screening practice, and to provide evidence for the prevention and control strategy of birth defects. Methods: Since July 2019, Hebei province had carried out the NIPT project providing first-line screening for eligible pregnant women in the area (except for those who were not applicable). Pregnant women with high risk received genetic counseling, prenatal diagnosis and intervention guidance. Low risk and false-positive ones received continuous detection and moved to prenatal diagnosis center for counseling and diagnosis if abnormities were discovered. All pregnant women were followed up to learn about pregnancy outcomes and newborn health status. Detection results and clinical data of pregnant women participating the NIPT project from July 2019 to July 2020 were collected. The detection results and effect of NIPT were analyzed. Results: (1) Basic information of the screened population: A total of 424 330 pregnant women were screened, and 423 596 were successfully detected, with a success rate of 99.83% (423 596/424 330). The age of pregnant women was (28.8±4.5) years old; the gestational age of screening was (16.6±2.3) weeks; the proportion of advanced-age pregnant women (≥35 years old) was 10.18% (43 132/423 596); in vitro fertilization-embryo transfer (IVF-ET) rate was 1.58% (6 713/423 596); the twin rate was 1.38% (5 849/423 596); the proportion of primipara was 34.23% (144 977/423 596). (2) Screening results and detection performance: totally, 325, 73 and 20 pregnant women were diagnosed with trisomy 21, 18 and 13; the sensitivity were 99.39%, 100.00% and 100.00%; the specificity were 99.98%, 99.99% and 99.98%; the positive predictive value were 75.76%, 68.87% and 21.51%, respectively. Besides, 249 190 pregnant women were received supplementary reports as well, and 255, 10 and 9 were confirmed for sex chromosome aneuploidy, other autosomal aneuploidy and deletion/duplication syndrome; the positive predictive value were 37.78%, 6.06% and 32.14%, respectively. The sensitivity of NIPT for target trisomy (trisomy 21, 18 and 13) screening in advanced-age, IVF-ET and twin pregnant women were 99.29%, 100.00% and 90.00%, respectively; the specificity were 99.93% for all; the positive predictive value were 82.25%, 61.54% and 69.23%, respectively. Conclusions: NIPT has a significant effect and good performance in the first-line screening of fetal chromosome aneuploidy in the whole population, which might provide reference for the improvement of birth defect prevention and control strategy.
目的： 评价无创产前检测（NIPT）做为一线筛查方法在胎儿染色体非整倍体筛查实践中的效果。 方法： 河北省自2019年7月开展“NIPT民生项目”，为辖区内符合条件的孕妇（不适用人群除外）提供NIPT一线筛查，高风险孕妇接受遗传咨询、产前诊断和指导干预，低风险和假阳性孕妇继续进行产前检查，发现异常后再次到产前诊断中心遗传咨询并产前诊断。对所有孕妇进行随访，了解妊娠结局与新生儿健康状况。收集2019年7月至2020年7月接受NIPT一线筛查孕妇的检测结果和临床数据，统计分析NIPT一线筛查的检测性能指标。 结果： （1）筛查人群基本信息：共筛查孕妇424 330例，成功检测423 596例，检测成功率为99.83%（423 596/424 330）。成功检测孕妇的年龄为（28.8±4.5）岁，筛查孕周为（16.6±2.3）周，高龄孕妇（≥35岁）占比为10.18%（43 132/423 596），体外受精-胚胎移植（IVF-ET）受孕孕妇占比为1.58%（6 713/423 596），双胎妊娠孕妇占比为1.38%（5 849/423 596），初产妇占比为34.23%（144 977/423 596）。（2）筛查结果与检测性能：21三体、18三体和13三体分别确诊325例、73例和20例，敏感度分别为99.39%、100.00%和100.00%，特异度分别为99.98%、99.99%和99.98%，阳性预测值分别为75.76%、68.87%和21.51%；249 190例孕妇同时出具补充报告，性染色体非整倍体、其他常染色体非整倍体和缺失或重复综合征分别确诊255例、10例和9例，阳性预测值分别为37.78%、6.06%和32.14%。NIPT筛查高龄、IVF-ET受孕、双胎妊娠孕妇目标染色体三体（21、18、13三体）的总体敏感度分别为99.29%、100.00%和90.00%，特异度均为99.93%，阳性预测值分别为82.25%、61.54%和69.23%。 结论： NIPT用于胎儿染色体非整倍体的全人群一线筛查效果显著、性能良好，可以为完善出生缺陷防控策略提供参考依据。.