3 | RESULTS
A total of 108 CAT cases were identified by prenatal echocardiography, of which 10 were detected before 20 weeks of pregnancy, 3 in the third trimester, and the remaining 95 in the second trimester between 20 and 28 weeks. Forty-seven cases were the A1 type (43.5%, 47/108), 51 cases were the A2 type (47.3%, 51/108), 9 cases were the A3 type (8.3%, 9/108), and 1 case was the A4 type (0.9%, 1/108). The A1 and A2 prenatal types were the most common, accounting for 90.7% (98/108) of this cohort, but only 1 case of the A4 type was associated with an aberrant right subclavian artery (Figures 4a, 4b). Among them, 22 cases (20.4%) were isolated CAT, 56 cases (51.8%) were complicated with complex intra-cardiac structural abnormalities, including total endocardial cushion defects, single atrial-single ventricle, hypoplastic left heart syndrome, persistent superior vena cava, atrial isomerism syndrome, total anomalous pulmonary venous collection, left aortic arch with aberrant right subclavian artery and left ductus arteriosus, right aortic arch with aberrant left subclavian artery and left ductus arteriosus, mirror image right aortic arch and left brachiocephalic vein, etc (Table 1). 30 cases (27.8%) were complicated with intra-cardiac and extra-cardiac structural abnormalities. A total of 55 systemic malformations were detected in 30 foetuses with abnormal extra-cardiac structures, of which 17 were combined with 1 abnormality in another system, 5 were combined with 2 other system abnormalities, 4 were combined with 3 other system abnormalities, and 4 cases were combined with 4 other system abnormalities. The extra-cardiac system, particularly the facial and physical abnormalities, had the highest incidence (40.0%), followed by the urinary system (14.5%) and the nervous system (14.5%) (Table 2). The STIC images were completely displayed in 88 cases (81.5%), but satisfactory STIC volume images were not obtained in the other 20 cases.
The pregnancy outcomes of all 108 foetuses were followed up. Among the 22 foetuses with isolated CAT, 1 case died in utero, 7 of the 16 foetuses died after birth, and 5 pregnant women and their families terminated their pregnancies after antenatal consultation. Of the 86 cases of PTA complicated with other malformed foetuses, 7 cases chose to continue the pregnancy and received timely surgical treatment after delivery. Among them, 2 cases were in good health. The remainder were combined with various complications. Eight intrauterine deaths, 10 postnatal deaths and 61 cases of pregnancy termination due to complicated intra-cardiac and extra-cardiac malformations were encountered. The incidence of combined other malformations was higher than that of isolated PTA, resulting in an adverse pregnancy outcome (20.37% vs 79.63%, P < 0.05; Table 3).