Department of Obstetrics and Gynecology, Faculty of Medicine, Prince of Songkla University Hat Yai, Hat Yai, Songkhla, Thailand.
PLoS One. 2021 May 13;16(5):e0251381. doi: 10.1371/journal.pone.0251381. eCollection 2021.
To evaluate the efficacy of the quadruple test for potential use as a Thai national policy for Down syndrome (DS) screening and establish an accurate equation for risk estimation of Down syndrome based on gestational age, weight and the ethnic-specific reference range of our population.
A prospective study was conducted on singleton pregnancies at 14 to 21 weeks of gestation to evaluate the efficacy of quadruple DS screening using the automatically calculated Western European descent factor (WF) in our population and the impact of screening using a specific Thai ethnic factor as well as to establish an equation for the risk estimation of DS based on gestational age, weight and a local Thai ethnic factor to correct for the impact of ethnic factor on the screening efficacy.
Of a total of 5,515 women, 12 cases of DS and 8 cases of other aneuploidies were found. The detection rate, false positive rate and specificity were 75.0%, 9.1% and 90.9%, respectively, by automatic calculation with the widely used WF; the screening efficacy was lower when used in Asian populations than in other studies. The best-fitted regression equation of serum quadruple screening of AFP, free β-hCG, uE3 and inhibin A was established by adjustment for gestational age (GA) in days, maternal weight and our Thai-specific ethnic reference range which was created for this study. Calculations with our Thai-specific ethnic model gave a better detection rate of 83.3%, a false positive rate of 9.6% and specificity of 90.4%.
The serum quadruple test had a lower detection rate than expected when the risk estimation was based on the WF reference range. The serum quadruple test using WF had significantly different levels when corrected with our ethnic-specific factor. Using our local ethnic specific model could increase the detection rate of DS screening in Thailand with a minimal increase in false positive rates. Our findings indicate that DS screening should be adjusted with an appropriate individual ethnic factor when used for national screening.
评估四联试验在唐氏综合征（DS）筛查中的应用效果，建立适合泰国人群的基于年龄、体重和特定种族参考范围的 DS 风险估算方程。
对 14-21 孕周的单胎妊娠进行前瞻性研究，评估在本人群中使用自动计算的西方欧洲血统因子（WF）进行四联 DS 筛查的效果，以及使用特定的泰国种族因子进行筛查的效果，并建立基于年龄、体重和本地泰国种族因子的 DS 风险估算方程，以校正种族因子对筛查效果的影响。
共 5515 名女性中，发现 12 例 DS 和 8 例其他非整倍体。自动计算广泛使用的 WF 时，检出率、假阳性率和特异性分别为 75.0%、9.1%和 90.9%；在亚洲人群中的筛查效果低于其他研究。通过调整胎龄（GA）天数、母亲体重和本研究创建的泰国特定种族参考范围，建立了 AFP、游离β-hCG、uE3 和抑制素 A 的血清四联筛查最佳拟合回归方程。使用我们泰国特有的种族模型计算得出的检出率为 83.3%、假阳性率为 9.6%、特异性为 90.4%，效果更好。
基于 WF 参考范围进行风险评估时，血清四联试验的检出率低于预期。使用我们特定种族的因子校正后，血清四联试验的 WF 水平有显著差异。使用我们当地的特定种族模型可以在最小增加假阳性率的情况下提高泰国 DS 筛查的检出率。我们的研究结果表明，DS 筛查在用于全国性筛查时应根据适当的个体种族因素进行调整。
