EN
Most heart defects form between 4 and 6 weeks after fertilization. The detection rate is still growing. Despite significant progress in prenatal diagnosis some cases still go undetected. We present two cases of similar defects: prenatally detected and undetected, both presenting with a normal four chamber view in mid-pregnancy. We compared the follow-up of both neonates along with sustained health and economic consequences. The dynamics of the development of heart defects during prenatal life suggests the legitimacy to perform additional, late echocardiography exams (35-38 weeks of gestation)