中孕期胎儿鼻骨缺失与发育不良在筛查染色体异常的应用价值

Application value of absent or hypoplastic fetal nasal bone in screening chromosomal abnormalities in the second trimester

目的探讨中孕期胎儿鼻骨回声缺失及发育不良在染色体异常筛查方面的临床应用价值。方法回顾232例中孕期经超声检查发现鼻骨发育异常的单胎胎儿,比较胎儿鼻骨回声缺失与发育不良染色体异常检出率的差异,比较胎儿鼻骨发育异常合并结构畸形与合并超声软指标染色体异常检出率的差异。结果 232例鼻骨发育异常胎儿共检出染色体核型异常34例(14.66%,34/232)。鼻骨缺失组119例,检出染色体核型异常25例(21.01%,25/119),其中21-三体20例,18-三体4例,13-三体1例。鼻骨发育不良组113例,检出染色体核型异常9例(7.96%,9/113),其中21-三体6例,18-三体1例,47,XYY 1例,衍生染色体1例。鼻骨缺失组染色体核型异常检出率显著高于鼻骨发育不良组,差异有统计学意义,χ~2=7.885,P<0.01。鼻骨发育异常合并结构畸形34例,染色体异常21例;鼻骨发育异常合并其他超声软指标阳性37例,染色体异常11例;单纯鼻骨发育异常161例,染色体异常2例。胎儿鼻骨发育异常合并结构畸形染色体异常检出率显著高于鼻骨发育异常合并其他超声软指标阳性,差异有统计学意义,χ~2=7.345,P<0.01。所有鼻骨发育异常胎儿接受微阵列检查27例,检出染色体片段异常5例(18.52%,5/27)。结论中孕期胎儿鼻骨发育异常是染色体异常的重要线索,胎儿鼻骨缺失比鼻骨发育不良染色体异常发生率增高,结合结构畸形及超声软指标的检测可极大提高产前胎儿染色体异常的检出率。

Objective To explore the clinical value of fetal absent or hypoplastic nasal bone in screening chromosomal abnormalities in the second trimester. Method 232 cases of single fetus with absent or hypoplastic nasal bone were retrospectively analyzed by prenatal ultrasound scanning during the second trimester.To compare the incidence of chromosomal abnormalities between fetal absent and hypoplastic nasal bone,and compare the incidence of chromosomal abnormalities in fetuses with nasal bone dysplasia combined structural abnormalities and combined ultrasonographic soft markers. Results A total of 34 cases with chromosomal karyotype abnormalities were detected among 232 fetuses(14.66%,34/232).There were 119 cases in absent nasal bone group,25 cases with chromosomal karyotype abnormalities were detected(21.01%,25/119),including 20 cases with trisomy 21,4 cases with trisomy 18,1 case with trisomy 13.There were 113 cases in hypoplastic nasal bone group,9 cases with chromosomal karyotype abnormalities were detected(7.96%,9/113),including 6 cases with trisomy 21,1 case with trisomy 18,1 case with 47,XYY,and1 case with chromosome derivation.There were 34 cases of nasal bone dysplasia with structural abnormalities and 21 cases of chromosome abnormality.There were 37 cases with nasal bone dysplasia combined with other ultrasonographic soft markers and 11 cases with chromosome abnormality.There were 161 cases of with isolated nasal bone dysplasia and 2 cases of chromosome abnormality.The detection rate of fetal nasal bone dysplasia with structural abnormalities chromosome abnormality was significantly higher than that of nasal bone dysplasia with other ultrasonographic soft markers(χ^2 =7.345 ,P <0.01).Moreove,a total of 27 cases by chromosomal microarray analysis,and 5 cases presented chromosomal abnormalities (18.52%,5/27). Conclusions dysplasia nasal bone is an important clue of chromosomal abnormality in fetuses at the second trimester,the incidence of chromosomal abnormalities in fetal absent nasal bone was significantly higher than that in hypoplastic nasal bone.The detection rate of prenatal fetal chromosome abnormality can be greatly improved by dysplasia nasal bone combining structural abnormalities and ultrasonographic soft markers.