Pulmonary atresia (PA)/critical stenosis (CS) with intact ventricular septum (PA/CS-IVS) is a rare congenital heart disease (CHD), that presents heterogeneously. Prognosis is conditioned by the possibility of achieving a primary repair with biventricular circulation (BV) or a one-and-a-half ventricle solution vs. a palliative approach bound to a univentricular (UV) circulation in which both survival and quality of life are significantly impaired. Predicting UV circulation prenatally is still a challenge. The aim of this study is: 1/ to evaluate the natural history of the disease and develop a prognostic model for the prediction of transplantation-free survival with a biventricular or a one-and-a-half repair at 2 years postnatal age 2/ To develop a model to predict the risk of right ventricle dependent coronary circulation 3/ To evaluate prenatal and postnatal outcomes in non-intervened fetuses with a confirmed postnatal diagnosis of PA-CS/IVS including Intrauterine death, neonatal/Infant death, number of required postnatal procedures, need for oxygen support, need for cardiac transplantation