Acute Fatty Liver of Pregnancy - Causes, Symptoms, Diagnosis, and Treatment

What Is an Acute Fatty Liver of Pregnancy?

Acute fatty liver of pregnancy (AFLP) is a rare, lethal (life-threatening) complication of pregnancy that occurs in the third trimester or early postpartum period. Excessive fat cells in the maternal liver cause dysfunction or failure, leading to maternal and fetal complications or death. It is a true obstetric emergency.

What Causes Acute Fatty Liver of Pregnancy?

The exact causes are unknown, but this disease has been linked to abnormal fetal fatty acid metabolism. According to some research, AFLP may be an inherited problem.

What Are the Risk Factors for Acute Fatty Liver of Pregnancy?

AFLP is a rare condition, but it is more likely to happen in the following conditions:

• Deficiency of fetal long-chain 3-hydroxy acyl CoA dehydrogenase deficiency (LCHAD) enzyme.

• Primigravidas (first pregnancy).

• Preeclampsia.

• Obesity.

• Diabetes.

• Male fetus.

• Pregnant with twins (multiple gestations).

A causal relationship between these risk factors and AFLP has not yet been proven. A hypothesis showed that multiple gestations may be associated with an increased risk of AFLP. The reason is that there is an increased production of fatty acid metabolites by more than one fetus. Ethnicity is not linked with AFLP. Use of drugs such as Acetylsalicylic acid and AFLP are found to be linked with each other. These drugs tend to inhibit trifunctional protein and long-chain fatty acid oxidation in mitochondria. This may cause AFLP.

What Are the Signs and Symptoms of Acute Fatty Liver of Pregnancy?

• Nausea, vomiting, excessive thirst, and anorexia (lack of desire to eat).

• Abdominal pain in the top right side.

• Headache, tiredness, and confusion.

• Fever.

• Jaundice (yellowing of the skin, eyes, and mucous membranes).

• Preeclampsia (high blood pressure and swelling).

• Detrimental effect on the fetus.

How Is Acute Fatty Liver Diagnosed In Pregnancy?

The initial symptoms related to the acute fatty liver of pregnancy are common to many other health conditions, thus making the diagnosis more challenging.

Routine investigations like patient history and clinical features mimic conditions such as acute viral hepatitis (liver inflammation due to hepatitis viruses), preeclampsia (very high blood pressure during pregnancy), HELLP (hemolysis, elevated liver enzymes, and low platelets during pregnancy) syndrome, intrahepatic cholestasis, etc. The doctor must rule out these conditions first before diagnosing acute fatty liver in pregnancy.

Basic tests performed are:

• Blood Tests - To rule out other disorders.

• Ultrasound- Sound waves, a computer to make images of blood vessels, tissues, and organs are used to make images.

• CT Scan (Computed Tomography)- A combination of X-rays and a computer are used to make detailed images of the body.

• Liver Biopsy- Performed to obtain a definitive diagnosis. There are increased chances of blood loss and bleeding-related complications, so it is less preferred.

The Swansea Criteria: It is mainly used for early diagnosis of acute fatty liver of pregnancy. It is a set of various parameters; the presence of six or more of these criteria in the absence of any other cause of liver disease indicates acute fatty liver of pregnancy. These criteria are:

• Vomiting.

• Abdominal pain.

• Polydipsia or polyuria.

• Encephalopathy.

• Elevated total bilirubin is more than 0.8 mg/dL.

• Hypoglycemia value less than 72 mg/dL.

• Elevated uric acid is more than 5.7 mg/dL.

• Leukocytosis values more than 11×109/l.

• Elevated AST/ALT (aspartate aminotransferase/alanine aminotransferase) more than 42 U/l.

• Elevated Ammonia levels of more than 66 µg/dL.

• Elevated Cr (creatinine) level of more than 1.7 mg/dL.

• Coagulopathy.

  • Prothrombin time (PT), more than 14 s.

  • Activated partial thromboplastin time (APTT) more than 34 s.

• Bright liver on ultrasound.

• Ascites (too much fluid build up in the stomach due to severe liver disease).

• Microvesicular steatosis on liver biopsy.

What Is the Difference Between Acute Fatty Liver of Pregnancy and HELLP Syndrome?

HELLP Syndrome: HELLP (Hemolysis, Elevated Liver enzymes, and Low Platelets) syndrome is a life-threatening pregnancy complication, usually associated with preeclampsia.

The difference between acute fatty liver of pregnancy and HELLP syndrome is how they originate. The symptoms are very similar but can be differentiated by values obtained in blood tests (ability to clot and platelet count).

As compared to the acute fatty liver of pregnancy, HELLP syndrome has:

• Higher blood pressure.

• Better ability to clot blood.

• Less severe abnormalities in liver function testing.

• Elevated uric acid.

• Unaltered sensorium.

• Absence of acidosis (the build-up of acid in the blood).

• No compromise of brain function.

• No alteration of kidney functions.

• Less bilirubin in the laboratory test.

• Hypertension present.

What Is the Treatment of Acute Fatty Liver of Pregnancy?

Early diagnosis, prompt delivery, and intensive supportive care are the cornerstones in managing the acute fatty liver of pregnancy. Steps needed:

• Admission to the intensive care unit (ICU).

• Supportive Management: Intravenous fluids, glucose, or blood products.

• Monitoring the fetus.

• After maternal stabilization, the baby is delivered by vaginal or cesarean birth.

• Hemodynamic monitoring is necessary during postpartum recovery due to the high risk of bleeding.

• Liver transplantation (a surgical procedure to remove the liver that does not function properly and replace it with a healthy liver from a donor) is rarely needed in complicated cases such as rupture of the liver, severe encephalopathy, severe metabolic acidosis, hepatic necrosis, or worsening coagulopathy.

• In many cases, the liver function returns to normal within a few weeks after baby delivery.

What Are the Possible Complications of Acute Fatty Liver of Pregnancy?

It is imperative to get an early diagnosis and prompt treatment, as acute fatty liver of pregnancy is a life-threatening condition.

1. Maternal Outcomes-

• Hypoproteinemia (low protein levels in the blood).

• Acute renal failure.

• Coagulopathy (a condition in which the blood's ability to form clots is impaired).

• Ascites (too much fluid builds up in the stomach due to severe liver disease).

• Disseminated Intravascular Coagulation (DIC) - Abnormal blood clotting in blood vessels.

• Preeclampsia - High blood pressure and swelling in legs during pregnancy.

• Maternal Death Due to Secondary Reasons - Sepsis, circulatory collapse, renal failure, pancreatitis, or gastrointestinal bleeding.

• Recurrence in subsequent pregnancies.

2. Fetal Outcomes-

• Preterm birth (premature delivery).

• Fetal death.

How to Prevent Acute Fatty Liver of Pregnancy?

Since the exact cause of acute fatty liver in pregnancy is unknown, it might be difficult to assess the preventive measures.

Conclusion:

Acute fatty liver of pregnancy (AFLP) is a rare, life-threatening disorder developing in the third trimester or early postpartum period (more common in the first pregnancy). Careful patient history, physical examination, and compatible laboratory and imaging results are needed to make the diagnosis. Liver biopsy is rarely indicated. The choice of treatment is prompt delivery of the infant and intensive supportive care for both the mother and the newborn.