To evaluate and analyze the prognosis of pulmonary atresia with intact interventricular septum (PA/IVS) in fetuses by echocardiography.

This is a retrospective study in which 19 fetuses diagnosed with PA/IVS by prenatal ultrasound at Suzhou City Hospital and Suzhou Wujiang Second People's Hospital from July 1, 2017 to June 30, 2022 were included. The development of the right ventricle of PA/IVS fetuses was classified according to the internal diameter Z value of the tricuspid value annulus (TV-Z), the ratio of left and right ventricular length to diameter (RV/LV), tricuspid regurgitation, and the presence of right ventricular dependent coronary circulation (RVDCC) detected by fetal echocardiography, and the fetal prognosis was analyzed.

According to the classification of the structure, 9 (9/19, 47%) fetuses with PA/IVS type Ⅰ were found to have right ventricular inflow tract and trabecular and infundibular regions, 4 (4/19, 21%) cases of type Ⅱ PA/IVS had the inflow tract and infundibulum, 3 (3/19, 16%) cases of type Ⅲ PA/IVS had only the inflow, and 2 (2/19, 11%) cases of type Ⅳ had the inflow tract and trabecular region. And one case with RVDCC.There were 7 cases (7/19, 37%) with a well-developed right ventricle; the TV-Z scores ranged from -1.83 to 0.90, with an average of -1.28; RV/LV ranged from 0.72 to 0.90, with an average value of 0.84. Eight cases (8/19, 42%) had moderate right ventricular dysplasia; the TV-Z scores ranged from -2.82 to -3.92, with an average value of -3.36; RV/LV ranged from 0.47 to 0.60, with an average value of 0.53. Three cases (3/19, 16%) had severe right ventricular dysplasia; TV-Z scores ranged from -4.13 to 5.86, with an average value of -5.02; RV/LV ranged from 0.36 to 0.49, with an average value of 0.43. In this series, 8 cases underwent balloon dilatation of the pulmonary valve or pulmonary valvuloplasty and biventricular correction, and 9 cases underwent induced labor. Two fetuses with moderate right ventricular dysplasia underwent Blalock-Taussig shunt and single ventricular palliative treatment.

TV-Z value, severity of tricuspid regurgitation, severity of right ventricular hypoplasia, and the presence or absence of RVDCC can affect the prognosis of PA/IVS fetuses. Echocardiography can be an effective means of evaluating the prognosis of PA/IVS fetuses.