Pulmonary stenosis and atresia with intact ventricular septum during prenatal life

Aim: To identify fetal echocardiographic characteristics predictive of perinatal outcome in cases with a prenatal diagnosis of pulmonary stenosis or pulmonary atresia. Patients and methods: We retrospectively reviewed the records and the videotapes of all the cases of pulmonary stenosis and pulmonary atresia diagnosed at our institutions between 1990 and 1999. The following measurements were obtained: diameters of right and left atria and ventricles and ventricular wall thickness; main pulmonary artery and aortic root diameter; direction of flow through the atrioventricular, aortic and pulmonary valves and through the ductus arteriosus. Perinatal outcome and follow-up of the survivors were available in each case. Results: There were 21 cases of pulmonary atresia. Eleven were diagnosed before 24 weeks and nine of them (82%) underwent termination of pregnancy. The survival rate was 50% among the 12 fetuses born at term. None of the fetuses that survived had a large right ventricle, while this was a finding in 50% of those that died. Among the fetuses that died, 83% had a hypertrophic right ventricular wall compared to 33% of the survivors. There were 12 cases of pulmonary stenosis. Three cases were diagnosed before 24 weeks but none underwent termination of pregnancy. All the fetuses with pulmonary stenosis were born at term and four died in the perinatal period. The survival rate was thus 66.6% (8/12). Three (75%) of the fetuses that died had reversed flow in the ductus arteriosus compared with one of the fetuses that survived. Conclusion: Our data suggest that a grossly enlarged right ventricle and/or a hypertrophied right ventricular wall in cases of pulmonary atresia and reversed flow in the arterial duct in cases of pulmonary stenosis are likely indicators of a poor prognosis.