探讨早孕期胎儿右位主动脉弓(RAA)的产前超声诊断学特征。

回顾性分析2019年4月至2022年7月于莱州市妇幼保健院超声科行早孕期胎儿规范化超声检查并经随访证实的12例RAA胎儿超声心动图资料，总结胎儿RAA早孕期超声诊断学特征。

12例RAA胎儿中8例为孤立性RAA，4例合并其他心内、外畸形。3例行遗传学检查，2例正常，1例为22q11微缺失。在三血管气管切面(3VT)上12例胎儿RAA表现为主动脉弓位于气管的右侧，9例动脉导管弓与主动脉弓间距增大，9例RAA合并迷走左锁骨下动脉与左位动脉导管形成"U"形血管环。3例RAA合并头臂动脉镜像分支(1例伴动脉导管缺如，1例伴左位动脉导管，1例伴右位动脉导管)未形成血管环，在3VT切面上2例表现为单一动脉弓(主动脉弓)，1例表现为右"V"形征。在非标准左心室流出道切面(LVOT)上11例表现为胎儿主动脉升部与弓部夹角增大。12例中4例引产后经病理解剖证实，8例经中孕期及产后超声心动图证实。

胎儿RAA在早孕期具有特征性的声像图特征，掌握RAA的产前声像图特征，对早期检出和诊断胎儿RAA有重要意义。

To explore the ultrasonographic features of fetal right aortic arch (RAA) in the first trimester.

The echocardiographic data of 12 fetuses with RAA in the first trimester who underwent standard fetal ultrasound examination and were confirmed by follow-up at Laizhou Maternal and Child Health Hospital from April 2019 to July 2022 were retrospectively analyzed, and the ultrasonic diagnostic characteristics of fetal RAA in the first trimester were summarized.

Twelve instances of RAA were observed. Among these, 8 cases were isolated RAA, and 4 cases presented with other intracardiac and extracardiac abnormalities. Three cases underwent genetic testing, 2 cases of which resulted in normal results, and 1 case of which revealed a confirmed 22q11 microdeletion. By using three vessels and trachea (3VT) view, the aortic arch of the 12 cases was located to the right of the trachea, and the distance between the ductus arteriosus and the aortic arch of the 9 cases was widened. Nine cases combined RAA with U-shaped vascular rings created by the malformed left subclavian artery and the left ductus arteriosus. Three fetal RAA cases with mirror branches on the brachiocephalic arteries (1 case without ductus arteriosus, 1 case with left ductus arteriosus, and 1 case with right ductus arteriosus) did not develop vascular rings. Two cases revealed a single artery arch (the aortic arch), while 1 case revealed the right " V" sign by using 3VT view. Eleven cases showed increased angle between aortic arch and aortic ascendens in the left ventricular outflow tract (LVOT) view of non-standard. Eight of the 12 cases were confirmed by fetal echocardiogram in the second trimester and postnatal echocardiography, and 4 cases were confirmed by autopsy.

Fetal RAA has the characteristic ultasonographic appearances in the first trimester. It is of great significance to grasp the prenatal ultrasonographic features for the early detection and diagnosis of fetal RAA.