Neonatal chylopericardium: coincidence or complication related to vascular access?

Introduction: Chylopericardium is a rare entity characterized by the accumulation of lipid-rich, milky fluid in the pericardial cavity, which may evolve into life-threatening complications such as cardiac tamponade. In neonates, most cases are idiopathic, though secondary causes include surgical injury, trauma, or lymphatic malformations. Clinical presentation ranges from incidental findings to acute hemodynamic collapse, representing a diagnostic challenge in fragile populations such as preterm infants. Case report: We report the case of a preterm male infant, born at 31 weeks’ gestation by cesarean section for severe preeclampsia. Shortly after birth he developed respiratory distress requiring surfactant therapy, invasive ventilation, and multiple central line attempts, complicated by malpositioned catheters. On the fifth day of life, progressive tachycardia, worsening respiratory distress, and anuria prompted echocardiography, which revealed a significant pericardial effusion. Ultrasound-guided pericardiocentesis yielded 21 mL of chylous fluid with triglyceride levels of 691 mg/dL and sterile cultures, confirming neonatal chylopericardium. Conservative management was initiated, including drainage, total parenteral nutrition, suspension of enteral feeding, and gradual reintroduction of adapted enteral nutrition. The infant showed favorable progression, with no recurrence of effusion, and was eventually discharged to intermediate care in stable condition. Conclusion: This case highlights the diagnostic and therapeutic challenges of neonatal chylopericardium, particularly in preterm infants where vascular trauma may be suspected but not evident. Early recognition combined with conservative management can be effective, avoiding surgical interventions and improving outcomes in this vulnerable population.