超声检测孕11～13+6周胎儿颈项透明层厚度诊断胎儿染色体畸变的临床意义分析

Clinical significance of ultrasonic testing of NT thickness in the diagnosis of fetal chromosomal aberration during 11-13+6 gestational weeks

目的探讨超声检测孕11~13^+6周胎儿颈项透明层(NT)厚度在胎儿染色体畸变中的诊断价值。方法选取2015年10月至2018年2月在本院行超声孕检的1200例11~13^+6周孕妇,均行经腹部超声检测NT厚度,对NT厚度≥2.5mm者行胎儿染色体核型分析,随访统计妊娠结局,计算NT厚度诊断胎儿染色体异常的价值,分析胎儿染色体畸变与NT增厚之间的关系。结果本组1200例孕妇均完成超声NT值测量,其中有58例孕妇出现NT增厚,胎儿染色体核型分析结果中有8例胎儿染色体核型异常,分别为1例18三体,3例21三体,1例13三体,1例15三体,1例45,X,1例47,XXX,所有孕妇均终止妊娠;有10例染色体正常但结构异常,分别为心脏结构畸形4例,胸腹水畸形1例,成骨发育不全4例,1例淋巴管囊肿,均终止妊娠;其余40例孕妇均顺利分娩。以NT厚度≥2.5mm筛查胎儿染色体异常的特异度为96.61%,灵敏度为94.74%,阴性预测值为99.91%,阳性预测值为31.03%,准确度为96.58%。结论孕11~13^+6周行超声检测NT厚度在胎儿染色体畸变中具有较高的诊断价值,可将胎儿NT厚度≥2.5mm作为产前筛查胎儿畸形的一项重要参考指标。

Objective To investigate the value of ultrasonic testing of fetal nuchal translucency(NT) thickness in the diagnosis of fetal chromosomal aberration during 11-13^+6 gestational weeks. Methods A total of 1200 pregnant women with ultrasound pregnancy examination during 11-13^+6 gestational weeks from October 2015 to February 2018 were selected, and they were given abdominal ultrasound to detect NT thickness. Fetal chromosome karyotyping analysis was performed in children with NT thickness≥2.5 mm. The pregnancy outcome was followed up, the value of NT thickness in the diagnosis of fetal chromosomal abnormalities was calculated, and the relationship between fetal chromosomal aberration and NT thickening was analyzed. Results Ultrasound NT values were measured in 1200 pregnant women in this group. Among them, 58 pregnant women showed NT thickening at 11-13^+6 weeks, and 8 cases of abnormal fetal karyotype were detected in fetal chromosome karyotyping analysis, 1 case of 18-trisomy, 3 cases of 21-trisomy, 1 case of 13-trisomy, 1 case of 15-trisomy, 1 case of 45, X, 1 case of 47, XXX, all pregnant women terminated the pregnancy. There were 10 cases of normal chromosome but with abnormal structure, including 4 cases of cardiac structural malformation, 1 case of hydrothorax and ascite malformation, 4 cases of osteogenesis imperfecta, and 1 case of lymphatic cyst, all of which terminated the pregnancy, and the remaining 40 pregnant women delivered smoothly. The specificity, sensitivity, negative predictive value, positive predictive value, accuracy of NT thickness≥2.5 mm screening in fetal chromosomal abnormalities were 96.61%, 94.74%, 99.91%, 31.03% and 96.58%. Conclusion Ultrasonic testing of fetal NT thickness in fetal chromosomal aberration during 11-13^+6 gestational weeks has higher diagnostic value. Fetal NT thickness≥2.5 mm can be used as an important reference index for prenatal screening for fetal malformations.