Abstract：
OBJECTIVE: To analyze the results of prenatal diagnosis and outcome of pregnancy for women with a high risk for fetal aneuploidies.
METHODS: A total of 747 cases of prenatal diagnosis by amniocentesis due to high risks by non-invasive prenatal testing (NIPT) were selected from January 2015 to March 2022 in the Drum Tower Hospital Affiliated to Nanjing University Medical School. The amniotic fluid samples were subjected to chromosomal karyotyping and/or chromosomal microarray analysis. All cases were followed up by searching the birth information or telephone calls, and the results were recorded. 2 test or F test were used for comparing the difference between the groups.
RESULTS: Among the 747 pregnant women with a high risk by NIPT, 387 were true positives, and the overall positive predictive value (PPV) was 51.81%. The PPVs for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13) and sex chromosome aneuploidies (SCA) were 80.24% (199/248), 60% (48/80), 14% (7/50) and 38.97% (106/272), respectively. The PPV for T21 was significantly higher than T18 and T13 (χ2 = 85.216, P < 0.0001). The PPV for other chromosomal aneuploidies and copy number variations (CNVs) were 11.11% (5/45) and 40.74% (22/52), respectively. The PPV for increased X chromosomes was significantly higher than X chromosome decreases (64.29% vs. 22.22%, χ2 = 5.530, P < 0.05). The overall PPV for elder women (≥ 35 years old) was significantly higher than younger women (69.35% vs. 42.39%, χ2 = 49.440, P < 0.0001). For T21 and T18, the PPV of Z ≥ 10 group was significantly higher than that for 3 ≤ Z < 5 group or 5 ≤ Z < 10 group (P < 0.05). Among 52 cases with a high risk for CNVs, the PPV for the ≤ 5 Mb group was significantly higher than the 5 Mb < CNVs < 10 Mb or > 10 Mb groups (60% vs. 30%60% vs. 23.53%, P < 0.05). Among the 387 true positive cases, 322 had opted for induced labor, 53 had delivered with no abnormal growth and development, and 12 were lost during the follow-up.
CONCLUSIONS: The PPVs for common chromosomal aneuploidies are related to the age and Z value of the pregnant women, which were higher in the elder group and higher Z value group. In addition, the PPV is associated with high risk types. The PPV for T21 was higher than T18 and T13, and that for 45,X was lower than 47,XXX, 47,XYY or 47,XXY syndrome. NIPT therefore has relatively high PPVs for the identification of chromosomal CNVs.
METHODS: A total of 747 cases of prenatal diagnosis by amniocentesis due to high risks by non-invasive prenatal testing (NIPT) were selected from January 2015 to March 2022 in the Drum Tower Hospital Affiliated to Nanjing University Medical School. The amniotic fluid samples were subjected to chromosomal karyotyping and/or chromosomal microarray analysis. All cases were followed up by searching the birth information or telephone calls, and the results were recorded. 2 test or F test were used for comparing the difference between the groups.
RESULTS: Among the 747 pregnant women with a high risk by NIPT, 387 were true positives, and the overall positive predictive value (PPV) was 51.81%. The PPVs for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13) and sex chromosome aneuploidies (SCA) were 80.24% (199/248), 60% (48/80), 14% (7/50) and 38.97% (106/272), respectively. The PPV for T21 was significantly higher than T18 and T13 (χ2 = 85.216, P < 0.0001). The PPV for other chromosomal aneuploidies and copy number variations (CNVs) were 11.11% (5/45) and 40.74% (22/52), respectively. The PPV for increased X chromosomes was significantly higher than X chromosome decreases (64.29% vs. 22.22%, χ2 = 5.530, P < 0.05). The overall PPV for elder women (≥ 35 years old) was significantly higher than younger women (69.35% vs. 42.39%, χ2 = 49.440, P < 0.0001). For T21 and T18, the PPV of Z ≥ 10 group was significantly higher than that for 3 ≤ Z < 5 group or 5 ≤ Z < 10 group (P < 0.05). Among 52 cases with a high risk for CNVs, the PPV for the ≤ 5 Mb group was significantly higher than the 5 Mb < CNVs < 10 Mb or > 10 Mb groups (60% vs. 30%60% vs. 23.53%, P < 0.05). Among the 387 true positive cases, 322 had opted for induced labor, 53 had delivered with no abnormal growth and development, and 12 were lost during the follow-up.
CONCLUSIONS: The PPVs for common chromosomal aneuploidies are related to the age and Z value of the pregnant women, which were higher in the elder group and higher Z value group. In addition, the PPV is associated with high risk types. The PPV for T21 was higher than T18 and T13, and that for 45,X was lower than 47,XXX, 47,XYY or 47,XXY syndrome. NIPT therefore has relatively high PPVs for the identification of chromosomal CNVs.
摘要：
目的：分析胎儿非整倍体高危孕妇的产前诊断结果及妊娠结局。
方法：选取2015年1月至2022年3月南京大学医学院附属鼓楼医院非侵入性产前检测（NIPT）高危羊膜腔穿刺产前诊断患者747例。对羊水样品进行染色体核型分析和/或染色体微阵列分析。所有病例均通过查询出生资料或电话随访,并记录结果。2检验或F检验用于比较组间差异。
结果：在NIPT高危的747名孕妇中，387是真正的阳性，总体阳性预测值（PPV）为51.81％。21三体(T21)的PPV，三体18(T18),13三体(T13)和性染色体非整倍体(SCA)占80.24%(199/248),60%(48/80),14%(7/50)和38.97%(106/272)，分别。T21的PPV显著高于T18和T13(χ2=85.216,P<0.0001)。其他染色体非整倍体和拷贝数变异(CNVs)的PPV分别为11.11%(5/45)和40.74%(22/52),分别。X染色体增加的PPV明显高于X染色体减少的PPV（64.29％vs.22.22%,χ2=5.530,P<0.05)。老年女性（≥35岁）的总PPV明显高于年轻女性（69.35%vs.42.39%,χ2=49.440,P<0.0001)。对于T21和T18，Z≥10组的PPV明显高于3≤Z<5组和5≤Z<10组（P<0.05）。在52例CNVs高风险患者中，≤5Mb组的PPV显著高于5Mb10Mb组(60%vs.30%60%vs.23.53%,P<0.05)。在387例真阳性病例中，322人选择了引产，53已交付，没有异常的生长和发育，12人在随访期间丢失。
结论：常见染色体非整倍体的PPV与孕妇的年龄和Z值有关，老年组较高，Z值较高。此外,PPV与高风险类型相关。T21的PPV高于T18和T13，45，X低于47，XXX，47，XYY或47，XXY综合征。因此,NIPT具有用于鉴定染色体CNV的相对高的PPV。
方法：选取2015年1月至2022年3月南京大学医学院附属鼓楼医院非侵入性产前检测（NIPT）高危羊膜腔穿刺产前诊断患者747例。对羊水样品进行染色体核型分析和/或染色体微阵列分析。所有病例均通过查询出生资料或电话随访,并记录结果。2检验或F检验用于比较组间差异。
结果：在NIPT高危的747名孕妇中，387是真正的阳性，总体阳性预测值（PPV）为51.81％。21三体(T21)的PPV，三体18(T18),13三体(T13)和性染色体非整倍体(SCA)占80.24%(199/248),60%(48/80),14%(7/50)和38.97%(106/272)，分别。T21的PPV显著高于T18和T13(χ2=85.216,P<0.0001)。其他染色体非整倍体和拷贝数变异(CNVs)的PPV分别为11.11%(5/45)和40.74%(22/52),分别。X染色体增加的PPV明显高于X染色体减少的PPV（64.29％vs.22.22%,χ2=5.530,P<0.05)。老年女性（≥35岁）的总PPV明显高于年轻女性（69.35%vs.42.39%,χ2=49.440,P<0.0001)。对于T21和T18，Z≥10组的PPV明显高于3≤Z<5组和5≤Z<10组（P<0.05）。在52例CNVs高风险患者中，≤5Mb组的PPV显著高于5Mb
结论：常见染色体非整倍体的PPV与孕妇的年龄和Z值有关，老年组较高，Z值较高。此外,PPV与高风险类型相关。T21的PPV高于T18和T13，45，X低于47，XXX，47，XYY或47，XXY综合征。因此,NIPT具有用于鉴定染色体CNV的相对高的PPV。
