Introduction
Twin to twin transfusion syndrome (TTTS) is a rare and serious condition that occurs in monochorionic (MC) pregnancies. It has a high perinatal morbidity and mortality if left untreated(1). In the recipient fetus biventricular hypertrophy, atrio-ventricular valves regurgitation, cardiomegaly, cardiac dysfunction and finally fetal hydrops may occur all of them mainly due to hypervolemic status. Moreover, right ventricular outflow obstruction (RVOTO), valvar pulmonary stenosis (PS) and atresia and left ventricular hypertrophic cardiomyopathy may also be presented. Donor twin on the other hand, usually shows little cardiac pathologies on echocardiography(2-5). Different types of cardiac abnormalities in TTTS can be explained by the altered fetal hemodynamics(6). Fetoscopic laser photocoagulation (FLP) at 16-26 weeks of gestation is the treatment of choice for TTTS. There are evidences of normalization of cardiac function in fetuses with severe TTTS after FLP Acquired structural cardiac anomalies are detected in a proportion of treated pregnancies, as a consequence of the altered hemodynamics(7). Due to increased rate of CHDs in TTTS, especially PS in recipient twin, prenatal and postnatal echocardiographic assessment is needed (8).