探讨胎儿先天性半月瓣缺如产前超声声像图特征。

对2010年1月至2015年12月孕11~13^＋6周在深圳市妇幼保健院和广西壮族自治区妇幼保健院产前超声检出半月瓣缺如的41例胎儿超声心动图像特征及临床结局进行总结分析。

41例半月瓣缺如胎儿中肺动脉瓣缺如28例（68.2%），主动脉瓣缺如1例（2.4%）；肺动脉瓣联合主动脉瓣缺如12例（29.4%）。早孕期超声检出胎儿半月瓣缺如21例（51.2%），其中肺动脉瓣联合主动脉瓣缺如均于早孕期超声心动图检出。二维超声显示20例胎儿颈项透明层（NT）增厚，1例胎儿因合并颅脑及神经管畸形NT值正常，15例合并胎儿水肿，6例合并颈部水囊瘤，16例心脏增大；超声心动图表现为三血管气管观可动态观察到主动脉和（或）肺动脉红蓝交替往返血流信号，即"进出征"。中孕期超声检出胎儿半月瓣缺如20例（48.8%），二维超声显示胎儿合并心外畸形6例。超声心动图多表现为主动脉和（或）肺动脉扩张，瓣环内无明显瓣叶启闭。超声随访过程中3例胎死宫内（均为肺动脉瓣联合主动脉瓣缺如）；38例胎儿母亲选择性引产，全组均无存活病例。引产后尸检诊断与产前超声检查结果一致。

先天性半月瓣缺如胎儿有特征性产前超声表现，早孕期发现颈项透明层增厚，三血管气管观显示主动脉和（或）肺动脉红蓝交替往返血流信号，即有典型"进出征"等图像特征，可早期诊断本病。

To describe the sonographic features of congenital absence of semilunar valve.

Forty-one cases of congenital absence of semilunar vavle diagnosed by prenatal ultrasound were identified within an established perinatal database in Shenzhen Maternity & Child Healthcare Hospital Affiliated to Southern Medical University from January 2010 to December 2015. The ultrasound and pathological examinations and prenatal outcomes were retrospectively reviewed. Comparative analysis was performed on autopsy with prenatal ultrasonograpgy.

There were a total of forty-one cases of congenital absent semilunar valve. Among them, there were 28 cases of absent pulmonary valves (68.2%, 28/41), 12 cases of absent pulmonary valves and absent aortic valves (29.4%, 12/41), and 1 case of isolate absent aortic valves cases (2.4%, 1/41). There were 21 cases (51.2%) diagnosed by first trimester fetal echocardiograms. A total of 12 cases of absent pulmonary valves and absent aortic valves were detected in the first trimester. Two-dimension (2D) sonographic features of congenital absent semilunar valve at the first trimester include increased nuchal translucency (NT) thickness (20 cases), only 1 case with the brain malformations and neural tube defects had normal nuchal translucency, generalized edema (15 cases), cervical cystic hygroma (6 cases), enlarged heart (16 cases). First trimester fetal echocardiograms showed ?to-and-fro? sign in the great artery at the three vessels and trachea view. There were 20 cases were diagnosed by the second trimester. Six cases were associated with other additional extracardiac abnormality. Fetal echocardiograms showed dilated great artery with complete absence of the aortic/pulmonary valve. No fetus survived in our study. Of the 41 cases, 3 cases had intrauterine death and 38 cases underwent elective termination. Autopsy confirmed the prenatal diagnosis.

Congenital absent semilunar valve have characteristic ultrasound features. Increased NT thickness and ?to-and-fro? sign is very helpful in diagnosing the congenital absence of semilunar vavle at the first trimester.