限制性胎盘嵌合对无创产前检测的影响及临床分析

Impact of confined placental mosaicism on non-invasive prenatal testing and pregnancy outcomes

目的探讨限制性胎盘嵌合(confined placental mosaicism,CPM)对无创产前检测(non-invasive prenatal testing,NIPT)以及妊娠结局的影响。方法应用低深度全基因组测序(copy number variation sequencing,CNV-seq)和单核苷酸多态性微阵列技术(single nucleotide polymorphism array,SNP-array)对8例NIPT假阳性病例进行胎盘多个位置的遗传学检测,结合临床资料分析CPM对NIPT以及妊娠结局的影响。结果在8例NIPT假阳性病例中,5例为CPM,分别为9号三体、13三体、21三体、22三体以及X三体CPM;胎盘不同区域的染色体异常比例差异明显(4%~80%)。5例CPM中,2例表现为胎儿生长受限(fetal growth restriction,FGR)合并其他超声异常,1例表现为孤立性FGR,其余2例生长发育正常。结论CPM是NIPT假阳性的重要原因,NIPT对CPM有较高的敏感性;CPM可能与FGR相关。重视CPM对于NIPT检测前后的遗传咨询以及妊娠管理有重要帮助。

Objective To assess the impact of confined placental mosaicism(CPM)on non-invasive prenatal testing(NIPT)and pregnancy outcomes.Methods Copy number variation sequencing(CNV-seq)and single nucleotide polymorphism array(SNP-array)were carried out on placental specimen sampled from eight pregnancies with confirmed false-positive NIPT results.The impact of CPM on NIPT and pregnancy outcomes were analyzed based on the laboratory tests and clinical characteristics.Results Five of the eight cases with false-positive NIPT results were proven to be CPM involving trisomy 9,13,21,22,and X,respectively.The mosaic ratios for different placental regions have varied from 4% to 80%.Two fetuses with confirmed CPM showed fetal growth restriction(FGR)and additional ultrasound abnormalities,1 fetus showed only FGR.The remaining two fetuses showed normal growth.Conclusion NIPT is highly sensitive to CPM,whilst CPM is an important cause for false-positive NIPT result.CPM may be associated with FGR.Investigation of the presence of CPM is important for both pre-and post-test genetic counseling and management of the pregnancy.