目的：讨论无创产前检测技术（non-invasive prenatal testing，NIPT）在筛查胎儿性染色体疾病方面的价值和意义。方法：选取2018年2月—2021年1月在我院接受NIPT检测的孕妇共19 327例，对于NIPT提示性染色体异常高风险的孕妇在知情同意后行羊膜腔穿刺术进行胎儿羊水染色体核型分析和染色体微阵列分析（chromosomal microarray analysis，CMA），对所有病例的检测结果及妊娠结局进行汇总分析。结果：19 327例孕妇中，NIPT提示性染色体异常高风险的孕妇共92例，阳性率为0.48%。其中81例孕妇接受了羊膜腔穿刺染色体核型分析及CMA检测，确诊45,X 13例（含嵌合体2例）、47,XXX 5例、47,XXY 8例、47,XYY 6例、性染色体微缺失微重复6例，其他染色体异常6例。NIPT检测技术对于性染色体异常的总的阳性预测值（positive predictive value，PPV）为45.68%；对于45,X（含嵌合体）、47,XXX、47,XXY、47,XYY、性染色体微缺失微重复的PPV分别为30.95%、50.00%、80.00%、75.00%、54.55%。NIPT对于性染色体非整倍体（含嵌合体）和微缺失微重复的PPV分别为44.29%和54.55%，差异无统计学意义（P＞0.05）；对于染色体数目增多和染色体数目减少（含嵌合体）的PPV分别为67.86%和30.95%，差异有统计学意义（P＜0.05）。染色体核型分析和CMA检测确诊发现性染色体异常的比例分别为38.27%和44.44%。结论：NIPT对于性染色体疾病具有较高的阳性预测值，但对不同类型性染色体异常的阳性预测值差异较大。NIPT可作为侵入性产前诊断之前的筛查方法，检测阳性孕妇应接受侵入性产前诊断进一步明确诊断。CMA比传统的染色体核型分析具有更高的异常检出率，建议对NIPT检测提示性染色体高风险的孕妇进行两项联合检查。
Objective: to discuss the value and significance of non-invasive prenatal testing (NIPT) in screening fetal sex chromosome diseases. Methods: a total of 19327 pregnant women who underwent NIPT in our hospital from February 2018 to January 2021 were selected. Pregnant women at high risk of NIPT suggestive chromosome abnormalities underwent amniocentesis after informed consent for fetal amniotic fluid chromosome karyotype analysis and chromosome microarray analysis (CMA). The test results and pregnancy outcomes of all cases were summarized and analyzed. Results: among the 19327 pregnant women, 92 pregnant women with high risk of sexual chromosome abnormalities suggested by NIPT, and the positive rate was 0.48%. Among them, 81 pregnant women underwent amniocentesis, karyotype analysis and CMA detection. 45, X 13 cases (including 2 chimeras), 47, XXX 5 cases, 47, XXY 8 cases, 47, XYY 6 cases, sex chromosome microdeletion and microduplication 6 cases and other chromosome abnormalities 6 cases were diagnosed. The total positive predictive value (PPV) of NIPT was 45.68%; The PPV of 45, X (including chimera), 47, XXX, 47, XXY, 47, XYY and sex chromosome microdeletion and microduplication were 30.95%, 50.00%, 80.00%, 75.00% and 54.55% respectively. The PPV of NIPT for sex chromosome aneuploidy (including chimera) and microdeletion microduplication were 44.29% and 54.55% respectively, and the difference was not statistically significant (P > 0.05); The PPV of chromosome number increase and chromosome number decrease (including chimera) were 67.86% and 30.95% respectively (P < 0.05). The proportion of sex chromosome abnormalities found by chromosome karyotype analysis and CMA detection were 38.27% and 44.44% respectively. Conclusion: NIPT has a high positive predictive value for sex chromosome diseases, but the positive predictive values for different types of sex chromosome abnormalities are quite different. NIPT can be used as a screening method before invasive prenatal diagnosis. Pregnant women with positive test should receive invasive prenatal diagnosis to further clarify the diagnosis. CMA has a higher abnormal detection rate than the traditional karyotype analysis. It is suggested to carry out two joint examinations for pregnant women with high risk of sexual chromosomes prompted by NIPT.