Safety of Omegaven in Pediatric Patients With Parenteral Nutrition-Associated Cholestasis (PNAC)

Inclusion Criteria: 1. Patient's parent(s) or legal guardian(s) has provided a signed and dated Informed Consent Form (ICF). 2. Patient is PN-dependent and within the past 21 days has been diagnosed with PNAC, defined as direct or conjugated bilirubin (DBil) ≥ 2.0 mg/dL with no other known cause of liver dysfunction at the time of enrollment. 3. Patient has feeding intolerance or at least one gastrointestinal disorder requiring PN. 4. Patient is \< 6 months corrected age (expected time of delivery to time of screening). Exclusion Criteria: 1. Patient has any other known cause of chronic liver disease such as hepatitis C, cystic fibrosis, biliary atresia, alpha-1-antitrypsin deficiency, passive hepatic congestion due to heart failure, etc. 2. Patient has known cirrhosis (liver biopsy is not required under this protocol). 3. Patient has known portal vein thrombosis (imaging studies are not required under this protocol). 4. Patient has previously received a liver-only or liver-inclusive transplant. 5. Patient has a major cardiac anomaly with hemodynamic instability. 6. Patient has a major life-threatening disease (e.g., sepsis requiring high-dose vasopressors, acute respiratory distress syndrome, veno-occlusive disease, cancer). 7. Patient has multi-organ failure, septic shock, hypotension requiring pressor therapy, persistent pulmonary hypertension requiring inhaled nitric oxides, or requires extracorporeal membrane oxygenation (ECMO) or similar intervention. 8. Patient has renal failure and requires dialysis. 9. Patient has a severe hemorrhagic disorder. 10. Patient has an INR \> 2.0. 11. Patient has severe hyperlipidemia or a severe disorder of lipid metabolism characterized by hypertriglyceridemia (i.e., serum triglyceride level \> 1,000 mg/dL). 12. Patient has a record of a previous T:T ratio ≥ 0.2 or had a previous diagnosis of EFAD. 13. Patient has a central nervous system anomaly (e.g., anencephaly) or any injury (e.g., grade 3 or 4 intraventricular hemorrhage, moderate to severe hypoxic ischemic encephalopathy) that will affect neurodevelopment. 14. Patient has been diagnosed with or is suspected to have a genetic disorder known to be associated with neurodevelopmental impairment (e.g., trisomy 21, 18, 13). 15. Patient has been diagnosed with or is suspected to have an inborn error of metabolism. 16. Patient has a known hypersensitivity to fish or egg protein or to any of the active ingredients or excipients of Omegaven. 17. Patient's medical care has been deemed futile by the medical team. 18. Patient is enrolled in any other study with an investigational medicinal product.