摘要目的:分析共同动脉干（CAT）胎儿的超声心动图表现及遗传学特征。方法:回顾性分析2010年11月至2024年11月于首都医科大学附属北京安贞医院胎儿心脏病母胎医学会诊中心检查的胎儿超声心动图共77 480例，初步诊断CAT胎儿106例，其中最终确诊CAT胎儿95例（0.1%，95/77 480）。分析CAT胎儿的超声心动图及遗传学特征。按Van Praagh改良分型法，根据肺动脉分支起源位置和室间隔缺损（VSD）存在与否，将CAT分为A1-A4型（合并VSD）和B1-B4型（不合并VSD）；根据是否合并心内外畸形，将CAT分为孤立型和复杂型。结果:①确诊为CAT的95例胎儿中，A型占90.5%（86/95），B型占9.5%（9/95）。9例B型CAT胎儿均无动脉干骑跨，其中8例为左心室发育不良，伴二尖瓣闭锁或缺如。②95例CAT胎儿中，14例为孤立型（14.7%，14/95），81例为复杂型（85.3%，81/95），其合并的主要心内畸形包括：单心室22例、完全型心内膜垫缺损12例、肺静脉异位引流10例、右弓并镜像分支16例、永存左上腔静脉14例。③31例胎儿进行了遗传学检测，18例有阳性结果，主要为22q11.21缺失综合征（29.0%，9/31）。结论:除VSD外，CAT胎儿最常见的心内合并畸形是单心室。不伴有骑跨的B型CAT，多有左心室发育不良伴二尖瓣闭锁或缺如。CAT胎儿最常合并的遗传学异常是22q11.21缺失综合征。产前超声心动图应明确CAT亚型及合并畸形，并强烈推荐进行遗传学检测，以便围生期咨询和预后分析。

abstractsObjective:To analyze the echocardiographic and genetic characteristics of fetuses with common arterial trunk（CAT）.Methods:A retrospective analysis was conducted on 77 480 fetal echocardiograms examined at the Maternal-Fetal Medicine center in Fetal Heart Disease of Beijing Anzhen Hospital from November 2010 to November 2024.Among them，106 fetuses were initially diagnosed with CAT，and 95 cases were ultimately confirmed（0.1%，95/77 480）. The echocardiographic and genetic features of CAT fetuses were analyzed. According to the modified Van Praagh classification，CAT was divided into types A1-A4［with ventricular septal defect（VSD）］and B1-B4（without VSD）based on the origin of the pulmonary artery branches and the presence or absence of a VSD. Additionally，CAT was categorized into isolated and complex types based on the presence of associated intracardiac or extracardiac anomalies.Results:① Among the 95 confirmed CAT fetuses，type A accounted for 90.5%（86/95），and type B accounted for 9.5%（9/95）. All 9 type B CAT fetuses exhibited no overriding of the arterial trunk ， with 8 cases showing left ventricular hypoplasia accompanied by mitral atresia or absence.② Of the 95 CAT fetuses，14 were isolated（14.7%，14/95） ， and 81 were complex（85.3%，81/95）.The main associated intracardiac anomalies included：single ventricle（22 cases），complete atrioventricular septal defect（12 cases），anomalous pulmonary venous drainage（10 cases），right aortic arch with mirror-image branching（16 cases），and persistent left superior vena cava（14 cases）. ③ Genetic testing was performed in 31 fetuses，with 18 showing positive results，primarily 22q11.21 deletion syndrome（29.0%，9/31）. Conclusions:Apart from VSD，the most common intracardiac anomaly associated with CAT fetuses is single ventricle. Type B CAT without trunk overriding is often associated with left ventricular hypoplasia and mitral atresia or absence. The most frequent genetic abnormality in CAT fetuses is 22q11.21 deletion syndrome. Prenatal echocardiography should clarify the CAT subtype and associated anomalies，and genetic testing is strongly recommended for perinatal counseling and prognostic evaluation.