Isolated Extremely Tortuous Fetal Ductus Arteriosus with Serpentine Appearance

Abstract Ductal aneurysms (DA) are rare vascular anomalies of the ductus arteriosus, often identified incidentally during fetal imaging or after the ductus has closed postnatally. They may occur in isolation or be associated with genetic and connective tissue disorders such as Marfan syndrome or Ehlers–Danlos syndrome. Prenatal detection of DA is crucial for guiding appropriate perinatal management, especially when the anatomy mimics more severe cardiovascular anomalies. We report a rare case of an isolated, extremely tortuous ductus arteriosus with a serpentine morphology identified at 35 + 3 weeks of gestation in a healthy 35-year-old pregnant woman. The ductus appeared dilated beyond the 95 th percentile and exhibited a double S-shaped configuration on fetal echocardiography. The aortic arch appeared hypoplastic, initially raising concern for coarctation. However, no flow reversal or cardiac dysfunction was observed. There was no associated structural or genetic anomaly. The fetus remained hemodynamically stable, and conservative management with serial ultrasounds was pursued. The patient was delivered vaginally at term, and postnatal echocardiography confirmed a hemodynamically insignificant patent ductus arteriosus, which resolved spontaneously by day 3 of life. Follow-up at 6 months showed normal cardiovascular findings. This case underscores the importance of careful prenatal evaluation and multidisciplinary management of suspected ductal anomalies. An extremely tortuous ductus arteriosus may mimic serious cardiovascular defects but can have a benign course. Conservative management with close follow-up is appropriate in isolated, asymptomatic cases. Increased awareness of such presentations can help avoid unnecessary interventions and reduce parental anxiety.