What are the risk factors and management strategies for Acute Fatty Liver of Pregnancy (AFLP)?

Risk Factors and Management of Acute Fatty Liver of Pregnancy (AFLP)

Prompt delivery and supportive care are the cornerstones of management for Acute Fatty Liver of Pregnancy (AFLP), which typically presents in the third trimester and is associated with significant maternal and fetal mortality if not recognized and treated early. 1

Risk Factors

• Pregnancy in the third trimester, particularly near term 1
• Primiparity (75% of cases occur in first-time mothers) 2
• Male fetus (63.3% of cases) 2
• Multiple gestation pregnancies 1, 3
• Pre-existing risk factors for pre-eclampsia (diabetes mellitus, hypertension, chronic kidney disease, autoimmune disease) 1
• Genetic factors: Association with fetal long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency 4

Clinical Presentation

• Initial symptoms often include nausea and vomiting (23% of cases) 5
• Other common symptoms include:
  • Fatigue, anorexia, and jaundice 2
  • Abdominal pain 3
  • Polydipsia/polyuria (in cases complicated by diabetes insipidus) 4
• Clinical features may include:
  • Jaundice, coagulopathy, and low platelets 1
  • Hypoglycemia (53% of cases) 3
  • Features of pre-eclampsia (hypertension, proteinuria) in approximately 50% of cases 1

Diagnostic Approach

• The Swansea criteria should be used for diagnosis, with ≥6 criteria highly correlating with clinical diagnosis 4
• Laboratory findings typically include:
  • Elevated liver enzymes (ALT <500 U/L) 1
  • Elevated bilirubin (<5 mg/dL) 1
  • Elevated alkaline phosphatase and GGT 1
  • Hypoglycemia 1, 3
  • Elevated creatinine 1
  • Coagulopathy with prolonged prothrombin time 1, 5
  • Disseminated intravascular coagulation (DIC) in >75% of cases 1
  • Thrombocytopenia 1
  • Elevated ammonia 1
• Imaging may show fatty infiltration of the liver and sometimes ascites 1

Management Algorithm

Step 1: Maternal Stabilization

• Admit patients with encephalopathy, elevated serum lactate, or high Swansea criteria score to intensive care 4, 6
• Correct coagulopathy and metabolic derangements before delivery 4, 6
• Monitor for and treat hypoglycemia, which is common in AFLP 4
• Control severe hypertension if present 6

Step 2: Expedited Delivery

• Early recognition of AFLP and prompt delivery are critical in achieving good outcomes 1
• Expedite delivery once coagulopathy and metabolic derangements have been treated 4, 6
• Decisions about mode of delivery should be made by a multidisciplinary team 4
• Emergency cesarean section may be necessary (performed in 12 of 15 cases in one study) 3

Step 3: Post-Delivery Management

• Provide comprehensive supportive care 3
• Consider plasma exchange in severe cases to improve maternal disease severity and decrease recovery time 4
• Consider N-acetylcysteine in women requiring intensive care admission 4
• Monitor for and manage complications:
  • Hepatic encephalopathy 3
  • Acute renal failure (occurs in 39% of cases) 5
  • Hypoproteinemia (75% of cases) 5
  • Coagulopathy (54% of cases) 5
  • Postpartum hemorrhage 3
  • Upper gastrointestinal hemorrhage 3

Step 4: Liver Transplantation Consideration

• Early referral to a transplant center for women with severe hepatic impairment 4
• Postpartum transplantation has occasionally been necessary in severe cases 1

Follow-up and Prognosis

• Recovery is typically rapid after delivery with supportive care 1
• Monitor liver function tests until normalization (should occur within 3 months post-delivery) 4, 6
• If liver function tests remain abnormal, investigate for underlying liver disease 6
• Screen newborns for long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency 4
• Maternal mortality has decreased from as high as 80% to approximately 7-18% with early recognition and management 1, 7
• Fetal mortality ranges from 9-23% 1

Special Considerations

• Anesthetic management should be carefully planned for patients requiring cesarean section 2
• AFLP can occasionally present in the postpartum period 8
• Prothrombin time (PT) and INR are risk factors for fatal complications 5

Early recognition, prompt delivery, and intensive supportive care are the keys to improving outcomes in this rare but potentially fatal obstetric emergency.