Eisenmenger syndrome (ES) is the end stage of pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD), which can occur in patients with large, unrepaired cardiac shunts (ventricular septal defects (VSD), atrial septal defects (ASD), and patent ductus arteriosus (PDA)). Pregnancy in Eisenmenger syndrome is uncommon and is poorly tolerated due to physiological changes that may lead to a risk of rapidly progressive cardiopulmonary decompensation, thrombotic complications, and sudden death. For these reasons, it is advisable, in this context, to avoid pregnancy or to undergo an early pregnancy termination within the tenth gestational week. The occurrence of severe preeclampsia in this situation leads to fatal maternal and fetal outcomes.We report the case of a 23-year-old female patient, gravida 1 nullipara at the thirty-fourth week of gestation, with a history of a persistent ductus arteriosus (PDA) in childhood that progressed to ES. She was admitted to the obstetric emergency for respiratory distress associated with signs of low cardiac output. CT pulmonary angiography and transthoracic echocardiography showed no pulmonary embolism, an enlarged pulmonary artery, dilated right cardiac chambers (ventricle and atrium) compressing the left ones, a right ventricular/left ventricular (RV/LV) ratio > 1, a persistent ductus arteriosus, and a calculated systolic pulmonary arterial pressure (PAPS) at 130 mmHg. She also had severe preeclampsia with evolutive HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome and intrauterine fetal death indicating fetal delivery under general anesthesia after platelets transfusion. At the end of the surgery, the patient presented a sudden death following a cardiac arrest despite 45 minutes of cardiopulmonary resuscitation.