Abstract
BACKGROUND: Umbilical venous catheterisation (UVC) is frequently used in neonates but may be complicated by malposition or migration. Extravasation is rare and can mimic other abdominal pathologies. CASE SUMMARY: We report a preterm infant, born at 27 weeks' gestation, who developed bilateral pneumothorax and spontaneous intestinal perforation requiring drainage. On day 8, the infant clinically deteriorated with persistent high-volume clear peritoneal drain output and worsening dehydration despite fluid escalation. Abdominal radiography confirmed UVC migration into the liver with possible extravasation. Following catheter removal, peritoneal drainage reduced dramatically, and the infant improved rapidly. He was discharged at 38 weeks' corrected age and remained well with age-appropriate development. CONCLUSION: UVC extravasation can masquerade as high-output peritoneal drainage in the setting of intestinal perforation, thereby delaying diagnosis. Persistent, unusually high peritoneal drainage should prompt consideration of catheter leakage. This rare presentation expands the spectrum of UVC-related complications described in the literature and emphasizes the importance of prompt recognition and management.