Even if all precautions are observed, complications are still unavoidable.5 Complication rates as high as 20% for venous catheters and 10% for arterial catheters have been reported.32 A venous catheter placed in the portal system may lead to hepatic necrosis, hemorrhage, and thrombus formation, which may lead to a pulmonary embolus or portal hypertension.3–6 Neonates are at higher risk for thromboembolic events because of their underdeveloped clotting mechanisms, small vessel diameters, and critical underlying diseases when compared with older children and adults.29 Phlebitis or nosocomial sepsis can ensue if strict aseptic technique is not followed.32 Rarely, the catheter can be transected or form a knot intravascularly.33,34 Vessel and bowel perforation from forceful manipulation of the catheter, an air embolus from an unflushed catheter prior to insertion, false track formation, cardiac arrhythmias, damage to cardiac valves, and myocardial perforation have all been reported.3,6,7,32,58 Necrotizing enterocolitis, biliary venous fistula, pericardial effusion, hypoglycemia from high positioning of an umbilical artery catheter, bladder rupture, congestive heart failure, hypertension, transection of an omphalocele, transection of the catheter, intravascular knots in the catheter, and Wharton's jelly embolus have also been reported.58–65 Occasionally, a persistent urachus in the umbilical cord stump may be mistaken for an umbilical vein. Catheterization of the urachus will result in the flow of urine, and not blood, from the catheter. This is easily identified and corrected.