Acute Fatty Liver of Pregnancy (AFLP) is an extremely rare but severe complication that primarily occurs late in the third trimester (30 to 38 weeks of gestation). This life-threatening condition is characterized by a rapid, excessive accumulation of fat within the mother’s liver cells, leading to acute liver insufficiency and multiorgan failure. The incidence is estimated to be between one in 7,000 and one in 15,000 pregnancies, demanding immediate medical attention. The underlying cause is linked to a defect in the fetus’s ability to metabolize fatty acids, often due to a deficiency in the long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) enzyme. This impairment causes toxic fatty acid byproducts to cross the placenta and overwhelm the mother’s liver, requiring prompt intervention to prevent catastrophic outcomes.
Identifying the Signs and Confirming Diagnosis
The initial presentation of AFLP can be subtle, often mimicking common pregnancy discomforts. Patients report persistent nausea, vomiting, and malaise, which may be dismissed until the condition progresses. More specific indicators include pain in the upper right or mid-upper abdomen, related to liver capsule swelling, along with excessive thirst and frequent urination. As liver function worsens, jaundice (yellowing of the skin and eyes) appears, often accompanied by confusion or lethargy due to toxin buildup.
Diagnosis relies on clinical suspicion and specific laboratory findings, as a liver biopsy is often avoided due to the patient’s unstable condition. Blood tests check for elevated liver enzymes (ALT and AST), though these levels are often lower than those seen in other liver disorders. A hallmark is hypoglycemia (dangerously low blood sugar), which occurs when the liver fails to produce glucose. Blood work also shows elevated bilirubin, indicating impaired bile excretion, and an abnormal clotting profile due to the liver’s failure to synthesize coagulation factors.
Diagnosis is commonly confirmed using the Swansea criteria, where the presence of six or more clinical and laboratory parameters strongly suggests AFLP. These criteria include vomiting, abdominal pain, elevated white blood cell count, and signs of renal impairment (high creatinine levels). While imaging like an ultrasound may show a “bright liver” appearance due to fatty infiltration, this finding is not sensitive enough to rule out the condition. Swift diagnosis based on these clues is paramount to initiating life-saving treatment.
Acute Stabilization and Supportive Care
Before definitive treatment, the mother’s critical status must be stabilized through intensive supportive care, ideally in an Intensive Care Unit (ICU). A primary concern is the rapid onset of hypoglycemia, which can quickly lead to coma and death. Hypoglycemia is corrected immediately with a continuous infusion of intravenous glucose (typically 5% Dextrose), while blood sugar levels are closely monitored.
Another major complication is coagulopathy, a bleeding disorder resulting from the liver’s inability to produce clotting proteins, which increases the risk of hemorrhage. Coagulopathy is managed by administering blood products like fresh frozen plasma (FFP) to replenish clotting factors and Vitamin K to aid synthesis. Close attention is also paid to fluid balance, as the patient is susceptible to dehydration (from vomiting) and overhydration, which can lead to pulmonary edema due to low plasma protein levels.
Supportive measures also involve managing potential organ damage, including acute kidney injury and pancreatitis. In severe liver failure, therapies like therapeutic plasma exchange may be used to temporarily remove toxins and correct metabolic imbalances before delivery. These interventions focus on optimizing the maternal condition and stabilizing physiological functions. This stabilization period is critical, as the disease process continues until the source of toxic fatty acids is removed.
The Definitive Resolution: Urgent Delivery
The only definitive treatment that stops AFLP progression is the urgent delivery of the fetus and the placenta. The placenta is the source of metabolic stress; its removal halts the influx of toxic fatty acid metabolites into the mother’s circulation. Once diagnosis is confirmed and the mother is stabilized, delivery must be expedited, regardless of gestational age. Expectant management is not an option, as delaying delivery significantly increases the risk of maternal and fetal mortality.
The mode of delivery (vaginal induction or Cesarean section) is complex, hinging on the mother’s stability and immediate fetal status. A Cesarean section is often chosen (in approximately 65% of cases), particularly if the mother’s condition is deteriorating or the fetus shows signs of distress. Maternal coagulopathy is a significant factor, as C-sections carry a higher risk of bleeding; clotting factors must be corrected with transfusions before surgery.
If the mother’s condition allows for a rapid vaginal delivery, labor induction may be attempted, but the process must be achievable within a short timeframe, often 24 hours. Maternal outcome is prioritized, and the selected method must achieve the quickest and safest resolution of the pregnancy. Once the placenta is delivered, the biological trigger for the disease is removed, marking the beginning of recovery.
Maternal and Infant Recovery
Following urgent delivery, the mother requires continued monitoring as the effects of multi-organ damage begin to reverse. Liver function typically improves rapidly, with enzyme and bilirubin values often normalizing within 7 to 10 days post-partum. Full recovery of the liver and kidneys usually takes a few weeks, and monitoring for complications like infection and residual renal dysfunction must continue.
The infant’s outcome relates closely to gestational age at delivery, as AFLP often necessitates preterm birth. The newborn may require admission to a neonatal intensive care unit (NICU) for specialized care related to prematurity. Given the association between AFLP and a fetal genetic defect (LCHAD deficiency), the infant must undergo testing for this metabolic disorder.
The mother’s long-term prognosis is generally excellent, with most women experiencing complete resolution. While the risk of AFLP recurrence in future pregnancies is low, carriers of the underlying genetic defect have a higher potential for recurrence. Genetic counseling is recommended for the mother and father to assess the risk of LCHAD deficiency in future children and guide planning for subsequent pregnancies.