背景:我们旨在评估基于中期妊娠超声软标记(USM)的无创产前筛查(NIPS)在低风险孕妇中的临床应用。方法:回顾性分析2015年4月至2019年12月的孕妇资料。我们的研究包括孕妇[预期分娩日期(EDC)<35岁;根据母体血清筛查,21三体(T21)和18三体(T18)的风险较低;提供中期妊娠USM(7种类型)]成功接受NIPS并具有可用随访信息。产前诊断为NIPS结果阳性的病例。所有患者术后随访6个月至2年。并获得了他们的临床结果。根据不同的USM进行亚组分析。结果:NIPS提示在10,023例中,37(0.37%)是非整倍体的高风险,包括4个T21,6个三体13(T13),和27个性染色体异常(SCA)。产前诊断证实10例非整倍体(0.10%),由两个T21和八个SCA组成。有SCA的八个胎儿由一个X单体组成,两个XXY,一个XXXY,一个XXX,一个XYY,和两个马赛克。在一个鼻骨缺失或发育不良的胎儿和一个具有回声心内病灶(EICF)的胎儿中检测到T21。用EICF在五个胎儿中检测到SCA,两个有多个软标记的胎儿,还有一个胎儿有回声肠.鼻骨缺失或发育不良的胎儿染色体非整倍体的阳性率明显更高(6.25vs.0.10%,p=0.017),回声肠(3.7vs.0.10%,p=0.029),和多个软标记(0.678vs.0.10%,p=0.045)比总胎儿高。3组NIPS阳性预测值(PPVs)均为100%,50%,100%,分别。EICF占研究人群的93.25%(9,346/10,023),而NIPS的PPV仅为20%。结论:NIPS是一项针对低危孕妇的高级筛查试验。在采样的10023名孕妇中,SCA比常染色体三体性更常见,EICF是最常见的USM,但预测最少的非整倍体。建议对超声显示鼻骨缺失或发育不良的低风险孕妇进行进一步的非整倍体评估,肠回声,或多个软标记。NIPS可以作为这些女性的二线补充筛查。
Background: We aimed to assess the clinical application of noninvasive prenatal screening (NIPS) based on second-trimester ultrasonographic soft markers (USMs) in low-risk pregnant women. Methods: Data of pregnant women between April 2015 and December 2019 were retrospectively analyzed. Pregnant women [age at expected date of confinement (EDC) of <35 years; low risks for trisomy 21 (T21) and trisomy 18 (T18) based on maternal serum screening; presenting second-trimester USMs (7 types)] who successfully underwent NIPS and had available follow-up information were included in our study. Cases with positive NIPS results were prenatally diagnosed. All patients were followed up for 6 months to 2 years after NIPS, and their clinical outcomes were obtained. Subgroup analyses were performed according to the different USMs. Results: NIPS suggested that among a total of 10,023 cases, 37 (0.37%) were at high risk of aneuploidy, including 4 T21, 6 trisomy 13 (T13), and 27 sex chromosome abnormalities (SCA). Ten cases with aneuploidy (0.10%) were confirmed by prenatal diagnosis, consisting of two T21 and eight SCA. The eight fetuses with SCA consisted of one monosomy X, two XXY, one XXXY, one XXX, one XYY, and two mosaicisms. T21 was detected in one fetus with absent or hypoplastic nasal bone and one fetus with echogenic intracardiac focus (EICF). SCA was detected in five fetuses with EICF, two fetuses with multiple soft markers, and one fetus with echogenic bowel. The positive rate of chromosomal aneuploidy was significantly higher in fetuses with absent or hypoplastic nasal bone (6.25 vs. 0.10%, p = 0.017), echogenic bowel (3.7 vs. 0.10%, p = 0.029), and multiple soft markers (0.678 vs. 0.10%, p = 0.045) than in the total fetuses. The positive predictive values (PPVs) of NIPS in these three groups were 100%, 50%, and 100%, respectively. EICF accounted for 93.25% (9,346/10,023) of the study population, whereas the PPV of NIPS was only 20%. Conclusion: NIPS is an advanced screening test for low-risk pregnant women. In the 10,023 pregnant women sampled, SCA were more common than autosomal trisomy, and EICF was the most frequent USM but the least predictive aneuploidy. Further aneuploidy evaluation is suggested for low-risk pregnant women whose ultrasound indicates absent or hypoplastic nasal bone, echogenic bowel, or multiple soft markers. NIPS can serve as a second-line complementary screening for these women.