整理不同类型胎儿肺动脉闭锁（PA），包括室间隔完整型PA（PA-IVS）、室间隔缺损型PA（PA-VSD）以及PA合并功能性单心室型（PA-FSV）的超声诊断要点、血流动力学特征及合并心外血管畸形情况，对胎儿PA诊断思路进行再探讨。

回顾性选取重庆市妇幼保健院2017年1月至2025年11月经产前超声心动图诊断为PA的胎儿共297例，收集3组（PA-IVS、PA-VSD和PA-FSV组）胎儿肺动脉闭锁部位（瓣膜vs主干）、三尖瓣反流程度、肺血供来源，PA-IVS和PA-VSD组心室发育程度及右心室依赖性冠脉循环（RVDCC）等方面表现，分析3组合并主动脉弓、静脉系统异常等心外血管畸形发生率。采用χ²检验或Fisher精确概率法比较组间肺动脉闭锁部位、右心室形态及三尖瓣反流、肺血供来源等情况的差异。

297例PA胎儿中PA-IVS组94例、PA-VSD组177例和PA-FSV组26例，3组在肺动脉闭锁部位（肺动脉瓣膜闭锁/肺动脉干闭锁：71/23 vs 20/157 vs 2/24）、肺血供来源（动脉导管逆行灌注/主-肺动脉侧支循环供血/二者合并：93/1/0 vs 137/29/11 vs 22/4/0）方面比较，差异均具有统计学意义（P均＜0.05）。同时，PA-IVS组和PA-VSD组在三尖瓣反流程度与右心室形态方面的差异均具有统计学意义（P均＜0.05），PA-IVS组主要表现为三尖瓣重度反流（68/94，72.4%），伴右心室发育不良（82/94，87.2%）；PA-VSD组主要表现为三尖瓣非重度反流（168/177，94.9%），伴心室发育均衡（166/177，93.8%）。13例RVDCC病例均来自PA-IVS组，所有病例均表现为右心室发育不良，其中3例（3/13，23.1%）合并三尖瓣重度反流，5例（5/13，38.5%）合并三尖瓣非重度反流，5例（5/13，38.5%）不伴三尖瓣反流。合并心外血管畸形方面，PA-VSD组合并右位主动脉弓、上腔静脉异常及无名静脉异常的比例显著高于PA-IVS组（24.3% vs 1.1%、30.5% vs 5.3%、35.6% vs 5.3%），差异均具有统计学意义（χ²=24.464、24.284、30.421，P均＜0.001）。

胎儿PA具有特征性的产前超声表现。通过观察室间隔完整性、右心室形态及三尖瓣反流状态，可综合分析心内血流动力学状态，有利于提高诊断准确率并为后续临床和遗传学检查咨询提供依据。

To summarize the prenatal echocardiographic diagnostic features, hemodynamic characteristics, and associated extracardiac vascular anomalies of fetal pulmonary atresia (PA), including pulmonary atresia with intact ventricular septum (PA-IVS), pulmonary atresia with ventricular septal defect (PA-VSD), and pulmonary atresia with functional single ventricle (PA-FSV), and to establish a systematic diagnostic approach for fetal PA.

A retrospective analysis was conducted on 297 fetuses diagnosed with PA (including PA-IVS, PA-VSD, and PA-FSV) by prenatal echocardiography between January 2017 and November 2025. The following features were assessed across the three groups: the level of pulmonary outflow obstruction (valvular vs main pulmonary artery), severity of tricuspid regurgitation (TR), sources of pulmonary blood flow, ventricular development in the PA-IVS and PA-VSD groups, and the presence of right ventricle–dependent coronary circulation (RVDCC). In addition, the incidence of associated extracardiac vascular anomalies—such as aortic arch abnormalities and systemic venous anomalies—was compared among the three groups. Group differences in the site of occlusion, right ventricular morphology, tricuspid regurgitation, and sources of pulmonary blood supply were compared using the χ² test or Fisher's exact test, as appropriate.

Among the 297 fetuses with PA, 94 were classified as having PA-IVS, 177 had PA-VSD, and 26 had PA-FSV. Significant differences were observed among the three groups with respect to the level of pulmonary atresia (valvular/main trunk: 71/23 vs 20/157 vs 2/24) and sources of pulmonary blood supply (anterior descending coronary artery perfusion/main-pulmonary collateral circulation/combination of both: 93/1/0 vs 137/29/11 vs 22/4/0) (all P<0.05). Furthermore, significant differences were identified between the PA-IVS and PA-VSD groups regarding TR severity and corresponding right ventricular morphology (all P<0.05); the PA-IVS group predominantly exhibited severe TR (68/74, 72.4%) in association with right ventricular hypoplasia (82/94, 87.2%), whereas the PA-VSD group mainly showed non-severe TR (168/177, 94.9%) with balanced ventricular development (166/177, 93.8%). All 13 cases of RVDCC occurred in the PA-IVS group and were uniformly associated with right ventricular hypoplasia; among these, 3 cases (23.1%) had severe TR, 5 (38.5%) had non-severe TR, and 5 (38.5%) had no TR. With respect to extracardiac vascular anomalies, the PA-VSD group demonstrated significantly higher rates of right aortic arch, persistent left superior vena cava, and innominate vein anomalies compared with the PA-IVS group (24.3% vs 1.1%, 30.5% vs 5.3%, and 35.6% vs 5.3%; χ²=24.464, 24.284, and 30.421, respectively; all P<0.001).

Fetal pulmonary atresia exhibits distinctive prenatal ultrasonographic features. Comprehensive assessment of ventricular septal integrity, right ventricular morphology, and tricuspid regurgitation facilitates an integrated understanding of intracardiac hemodynamics, thereby improving diagnostic accuracy and informing subsequent clinical management and genetic counseling.