Zhao G Y, Dai P, Hu S, Jiao Z H, Kong X D
The Genetics and Prenatal Diagnosis Center, the Department of Obstetrics and Gynecology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
Zhonghua Yi Xue Za Zhi. 2022 Aug 23;102(31):2452-2457. doi: 10.3760/cma.j.cn112137-20211215-02802.
To investigate the influence of -score and different risk factors on positive predictive value (PPV) of noninvasive prenatal testing (NIPT) for chromosome aneuploidies. A total of 81 838 NIPT samples from January 1, 2016 to May 31, 2021 in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. Invasive prenatal diagnosis was applied to verify the diagnosis of NIPT-positive results and the corresponding PPV was calculated. The PPV of the samples with different -score were compared. The women were divided into high-risk group and non-high-risk group: high-risk group (=39 114) included those with ultrasound soft index abnormalities, advanced maternal age or high risk for maternal serum screening, while non-high-risk group (=42 724) included those with intermediate risk for maternal serum screening or no indications. The differences of the PPV between these two groups were compared. Finally, the comprehensive influence of -score and different risk factors on PPV were analyzed. A total of 471 high-risk cases were detected by NIPT results, including 362 cases of trisomy 21, 77 cases of trisomy 18 and 32 cases of trisomy 13. For trisomy 21, trisomy 18 and trisomy 13, there were 226 cases, 46 cases and 6 cases which were confirmed via invasive prenatal diagnosis respectively. The corresponding PPV were 79.3% (226/285), 82.1% (46/56) and 27.3% (6/22), respectively. PPV of trisomy 21 and trisomy 18 were positively correlated with the corresponding -score (=0.92, 0.62, all <0.05), while trisomy 13 could not be analyzed due to the small sample size. The PPV of high-risk group was 85.2% (207/243), which was higher than that of the non-high-risk group with PPV of 59.2%(71/120, χ=30.30, <0.01). When the -score was between 3-<4 and 4-<5, the PPV of the high-risk group were 46.2%(12/26)and 62.5%(15/24) respectively, which were higher than those of the non-high-risk group [16.0%(4/25) and 14.3%(3/21), χ=4.10, 8.90, all <0.05]. With the increase of -score, there was no significant difference in PPV between the two groups (all >0.05). The PPV of trisomy 21 and trisomy 18 are positively correlated with -score. The PPV of high-risk group is higher than that of non-high-risk group. The combination of -score and other risk factors may provide more accurate genetic counseling for those with NIPT positive results.
探讨Z值及不同风险因素对染色体非整倍体无创产前检测（NIPT）阳性预测值（PPV）的影响。回顾性分析2016年1月1日至2021年5月31日郑州大学第一附属医院的81838例NIPT样本。采用侵入性产前诊断对NIPT阳性结果进行诊断验证并计算相应的PPV。比较不同Z值样本的PPV。将孕妇分为高危组和非高危组：高危组（n = 39114）包括超声软指标异常、孕妇年龄偏大或血清学筛查高危者，而非高危组（n = 42724）包括血清学筛查为临界风险或无指征者。比较两组间PPV的差异。最后，分析Z值和不同风险因素对PPV的综合影响。NIPT结果共检出471例高危病例，其中21 -三体362例、18 -三体77例、13 -三体32例。对于21 -三体、18 -三体和13 -三体，分别有226例、46例和6例经侵入性产前诊断确诊。相应的PPV分别为79.3%（226/285）、82.1%（46/56）和27.3%（6/22）。21 -三体和18 -三体的PPV与相应的Z值呈正相关（r = 0.92，0.62，均P < 0.05），而13 -三体因样本量小无法分析。高危组的PPV为85.2%（207/243），高于非高危组的PPV 59.2%（71/120，χ² = 30.30，P < 0.01）。当Z值在3 - <4和4 - <5时，高危组的PPV分别为46.2%（12/26）和62.5%（15/24），高于非高危组[16.0%（4/25）和14.3%（3/21），χ² = 4.10，8.90，均P < 0.05]。随着Z值增大，两组间PPV差异无统计学意义（均P > 0.05）。21 -三体和18 -三体的PPV与Z值呈正相关。高危组的PPV高于非高危组。Z值与其他风险因素相结合可为NIPT阳性结果者提供更准确的遗传咨询。
