孕中晚期胎儿超声正常奇静脉内径参考值及其临床意义

Reference range of inner diameter of azygos vein of normal fetal during the second and third trimesters and its clinic significance

目的:建立孕中晚期正常胎儿奇静脉内径参考值范围及其随孕周改变的规律,并探讨其对奇静脉扩张及下腔静脉离断的产前诊断价值。方法:连续性入选2010年8月至2013年12月,于北京安贞医院行产前超声心动图检查,且不合并明显结构性畸形胎儿6 323例,排除孕周<20周或>40周胎儿5例,在二维超声条件下测量奇静脉内径并探索奇静脉随孕周变化的回归方程。另外,回顾性分析9例经病理解剖或产后随访证实奇静脉扩张的超声心动图特征。结果:1正常胎儿奇静脉内径从孕20周平均值0.6mm至孕40周平均值3.0mm随孕周增加呈线性增长(r=0.983,P<0.01);2正常胎儿奇静脉内径与孕周的线性回归方程:D=(0.116×GA)-1.568(D为奇静脉内径,GA为孕周);38例奇静脉扩张继发于下腔静脉离断(其中2例合并左心房异构),1例继发于下腔静脉右心房开口处轻度狭窄。结论:孕中晚期正常胎儿奇静脉内径参考值范围及其随孕周变化规律的建立有助于提高对奇静脉扩张及下腔静脉离断的产前诊断率。

Objective： To establish reference range of fetal normal azygos vein（ Az V） diameter and its evolution rules with advancing gestation age during the second and third trimesters,and explore its value on prenatal diagnosing interruption of inferior vena cava（ IIVC）. Methods： 6323 cases consecutive fetuses performed fetal echocardiography examination between August 2010 and December 2013 were included and 5 cases with gestational age（ GA） 20 or 40 weeks were excluded. Inner diameter of Az V was measured under two-dimension ultrasound condition,and correlation between the Az V inner diameter and GA was analyzed and the regression equation was established. Additionally,retrospective study of 8 cases dilation of Az V confirmed by autopsy or postnatal echocardiography was performed. Results： 1In normal fetuses azygos vein diameter increased significantly throughout pregnancy,with a mean value of 0. 6 mm at 20 weeks and 3. 0 mm at 40 weeks. 2The regression equation of inner diameter of Az V to GA： D =（ 0. 116 × GA）- 1. 568. 3 Dilation of Az V was noted in 8 cases fetuses with IIVC and 1 case secondary to mild stenosis of IVC. Conclusion： The establishment of reference range of fetal normal azygos vein diameter and its changing rules with advancing gestation age during the second and third trimesters was helpful in prenatal diagnosing IIVC.