Abstract. Pathognomonic features of in utero premature restriction/closure of the ductus arteriosus (DA) are increased right ventricular afterload, impaired right ventricular function, and consequently tricuspid regurgitation and right heart dilation. The most common reason for constriction-closure of DA is maternal administration of non-steroidal anti-inflammatory drugs (NSAIDs) during the 3rd trimester of gestation. The idiopathic form is a rare event and, maybe, an underestimated abnormality that, if it is not promptly recognized, may result in severe fetal-neonatal compromise. We describe a case of a 38-year-old woman presenting at 34+0 weeks of gestation with a normally grown male fetus whose fetal echocardiography had shown right ventricular hypertrophy, a tortuous S-shaped DA and a significant pulmonary hyperflow. All signs were consistent of an idiopathic severe constriction of DA with a significant fetal cardiac involvement. The patient was admitted to a tertiary care center equipped with Neonatal Intensive Care Unit (NICU), and delivered by cesarean section at 34+4 weeks with a good maternal and neonatal outcome. Based on our experience and a review of the Literature we propose a management algorithm to use when dealing with preterm or early term pregnancy complicated by this fetal hemodynamic malfunction.