Department of Women's Health, University Women's Hospital Tübingen, Tübingen, Germany,
Department of Women's Health, University Women's Hospital Tübingen, Tübingen, Germany.
Fetal Diagn Ther. 2019;45(5):317-324. doi: 10.1159/000489121. Epub 2018 Jun 25.
To determine whether screening for trisomy 21 based on first-trimester combined screening (FTCS) with assessment of nasal bone (NB), tricuspid flow (TCF), and ductus venosus flow (DVF) results in similar false-positive rates compared to ultrasound and cell-free DNA (cfDNA) screening.
This is a subanalysis of a prospective randomized controlled trial which was performed between October 2015 and December 2016. Pregnant women with a normal first-trimester ultrasound examination at 11 to 13 weeks' gestation were randomized into two groups: (1) FTCS with assessment of the NB, TCF, and DVF (extended FTCS [eFTCS]), and (2) ultrasound + cfDNA screening. The false-positive rate in screening for trisomy 21 was defined as the primary outcome parameter.
The study population consisted of 688 women in each study arm. In the eFTCS group, the median delta fetal nuchal translucency thickness (NT) was 0.0 mm, free beta-hCG and PAPP-A were 0.96 and 1.11 MoM, and NB, TCF, and DVF PIV were abnormal in 0.9, 0.6, and 7.0% cases. In the ultrasound + cfDNA group, the median delta NT was 0.0 mm. In 10 pregnancies the cfDNA analysis was uninformative and the risk of trisomy 21 was based on eFTCS. There were no false-positive cases in the ultrasound + cfDNA group, whereas the false-positive rates were between 0.9 and 2.2% with eFTCS.
Screening for trisomy 21 based on ultrasound + cfDNA has a lower false-positive rate than screening based on eFTCS.
比较基于早孕期联合筛查（FTCS）结合鼻骨（NB）、三尖瓣血流（TCF）和静脉导管血流（DVF）评估与超声和游离胎儿 DNA（cfDNA）筛查检测 21 三体的假阳性率。
这是一项前瞻性随机对照试验的子分析，于 2015 年 10 月至 2016 年 12 月进行。11 至 13 孕周正常的早孕期超声检查的孕妇被随机分为两组：（1）FTCS 结合 NB、TCF 和 DVF 评估（扩展 FTCS[eFTCS]），和（2）超声+cfDNA 筛查。筛查 21 三体的假阳性率定义为主要结局参数。
每组研究人群均为 688 名女性。在 eFTCS 组中，中位数 delta 胎儿颈项透明层厚度（NT）为 0.0mm，游离β-hCG 和 PAPP-A 分别为 0.96 和 1.11MoM，NB、TCF 和 DVF PIV 异常分别为 0.9%、0.6%和 7.0%。在超声+cfDNA 组中，中位数 delta NT 为 0.0mm。在 10 例妊娠中，cfDNA 分析无意义，21 三体的风险基于 eFTCS。在超声+cfDNA 组中没有假阳性病例，而 eFTCS 的假阳性率在 0.9%至 2.2%之间。
基于超声+cfDNA 的 21 三体筛查的假阳性率低于基于 eFTCS 的筛查。
