What Is Acute Fatty Liver Of Pregnancy?

Acute fatty liver during pregnancy (AFLP) is also known as "obstetric acute pseudoyellow liver atrophy", "pregnant idiopathic fatty liver", "hepatic steatosis during pregnancy" and so on. Acute fatty liver in pregnancy is a rare and fatal disease unique to late pregnancy. The onset of the disease is rapid and the condition changes rapidly. It can occur at 28 to 40 weeks of gestation. It is more common in primiparas around 35 weeks of pregnancy. Hypertension disease, twins and male fetuses during pregnancy are more likely to occur. Clinical manifestations are similar to fulminant hepatitis.

Basic Information

nickname

Obstetric acute pseudoyellow liver atrophy, pregnancy-specific idiopathic fatty liver, liver steatosis during pregnancy

English name

acute fatty liver of pregnancy

Visiting department

Obstetrics and Gynecology

Multiple groups

Primiparas around 35 weeks, hypertension during pregnancy, multiple pregnancy

Common symptoms

Persistent nausea, vomiting, fatigue, epigastric pain or headache. Jaundice from several days to 1 week, progressive deepening, often without itching, abdominal pain, etc.

Causes of Acute Fatty Liver During Pregnancy

The cause of AFLP is unknown. Because AFLP occurs in the third trimester of pregnancy, there is hope for healing only when the pregnancy is terminated. Therefore, it is speculated that the hormonal changes caused by pregnancy can cause fatty acid metabolism to be impaired, causing free fatty acids to accumulate in liver cells and other organs such as kidney, pancreas, brain, etc. Multiple organ damage. In recent years, many cases of recurrence and their offspring have reported genetic defects, so some people have suggested that it may be a congenital genetic disease. In addition, multiple factors such as viral infection, poisoning, drugs (such as tetracycline), malnutrition, and pregnancy-induced hypertension may also be related to the damage of mitochondrial fatty acid oxidation.

Clinical manifestations of acute fatty liver during pregnancy

In the early stages of onset, there were only persistent nausea, vomiting, fatigue, epigastric pain, or headache. After several days to 1 week, the pregnant woman develops jaundice, which progresses progressively, often without itching. Abdominal pain can be limited to the right upper abdomen, or it can be diffuse. Patients often have high blood pressure, proteinuria, and edema. A few people have transient polyuria and thirst. If they continue to progress without childbirth, coagulation dysfunction, skin stasis, ecchymosis, gastrointestinal bleeding, bleeding gums, etc. are low. Blood sugar, disturbance of consciousness, mental symptoms and hepatic encephalopathy, oliguria, anuria, and renal failure often die within a short period of time.

1. There is acute severe upper abdominal pain in the early stage of onset, and amylase is increased, like acute pancreatitis.

2. Although jaundice is obvious and serum bilirubin is directly increased, urine bilirubin is often negative. Domestic reports of this phenomenon can also be seen in acute severe hepatitis.

3. Severe bleeding and renal impairment and elevated ALT are often present before liver failure, but mucus is usually normal.

4. Type B ultrasonography is a fatty liver waveform to help early diagnosis and confirm the diagnosis by pathological examination. The pathological features were the enlargement of hepatic lobular to middle zone cells, cytoplasm filled with fat vacuoles, and no massive hepatocyte necrosis.

Acute fatty liver examination during pregnancy

Laboratory inspection

(1) Blood routine, peripheral white blood cell count increased, up to (15.0 30.0) × 10 ⁹ / L, poisonous particles appeared, and erythrocytes and basophilic spotted red blood cells were seen; platelet count decreased, peripheral blood smears Hypertrophic platelets are visible.

(2) Moderate or severe increase in serum total bilirubin, mainly direct bilirubin, generally does not exceed 200 mol / L; mild or moderate increase in blood transaminase, ALT does not exceed 300U / L, there are enzymes Bile separation; blood alkaline phosphatase was significantly increased; serum albumin was low and lipoprotein was increased.

(3) The blood glucose can be reduced to 1/3 to 1/2 of the normal value, which is a significant feature of AFLP; the blood ammonia is increased, and it can reach 10 times the normal value when hepatic encephalopathy occurs.

(4) Prothrombin time and partial thromboplastin time are prolonged, and fibrinogen is decreased.

(5) Blood uric acid, creatinine and urea nitrogen were all increased. In particular, the increase in uric acid is not proportional to renal function, and sometimes hyperuricemia can exist before the clinical onset of AFLP.

(6) Urinary protein is positive and urinary bilirubin is negative. Urinary bilirubin negative is one of the more important diagnoses, but urinary bilirubin positive cannot exclude AFLP.

2. Other auxiliary inspections

(1) Imaging examination showed diffuse high-density areas in the liver area, uneven echo strength, snowflake shape, and typical fatty liver waveform. CT and MRI examinations can reveal excess fat in the liver, and the liver parenchyma shows a uniform and reduced density.

(2) Pathological examination is the only way to confirm the diagnosis of AFLP, and liver biopsy can be performed under B-mode localization. The typical changes of liver histology under light microscope are normal liver lobular structure, diffuse, microdroplet steatosis of hepatocytes, hepatocellular enlargement, liver cells near the central leaflet vein are more common; fatty vacuoles are scattered in the cytoplasm The nucleus is still located in the center of the cell and the structure is unchanged; cholestasis can be seen without inflammatory cell infiltration. HE staining showed balloon-like changes in liver cells, the earliest morphological change of the disease, and eosinophils were seen in the liver sinus. If liver cells are severely damaged, there will be significant necrosis and inflammatory reactions. Electron microscopy The mitochondria were significantly enlarged with rupture, looseness, and reduced ridges. Sliding and rough endoplasmic reticulum and Golgi are filled with lipid and swell.

The treatment period is closely related to the prognosis of the disease. Conservative treatment of maternal and infant mortality is extremely high, and liver puncture should be performed as early as possible to confirm the diagnosis. It is dangerous to perform liver puncture when there is a bleeding tendency after organ failure. After the diagnosis is made, childbirth should be given promptly and maximum supportive care should be given.

Acute fatty liver diagnosis during pregnancy

AFLP is prone to occur in the third trimester. First-born women, pregnancy-induced hypertension, and multiple births are high-risk factors for AFLP. More than half of AFLP is associated with pregnancy-induced hypertension. In addition to diagnosis based on medical history and clinical characteristics, auxiliary examinations can be referred to, and the diagnosis depends on histological examinations.

Differential diagnosis of acute fatty liver in pregnancy

Acute severe viral hepatitis

Liver failure is the main manifestation of acute severe viral hepatitis. It is clinically very similar to AFLP, and special attention should be paid to identification. Serum immunological tests for acute severe viral hepatitis are often positive (including antigen and antibody detection of hepatitis virus); transaminase is extremely elevated, often> 1000 U / L; and urine tribiliary is positive. Serum uric acid was not significantly increased, white blood cell count was normal, and renal dysfunction appeared later. Peripheral blood smears were free of juvenile red blood cells and dotted cells. Histological examination of the liver showed extensive hepatocytes, large patchy necrosis, and damage to the hepatic lobules.

2. Intrahepatic cholestasis during pregnancy

Intrahepatic cholestasis of pregnancy manifests as pruritus, elevated transaminase, jaundice, and increased bile acid. The AFLP did not have itching and elevated bile acids. The histological changes of cholestasis during pregnancy are mainly cholestasis in the central capillary bile ducts of the hepatic lobules and bile deposits in the placenta tissue; while the liver cells of AFLP are mainly infiltrated with fat droplets, and the placenta is not significantly changed.

3. Hypertensive liver disease during pregnancy and HELLP syndrome

There are free fatty acid deposits in renal tubule epithelial cells of AFLP. Impairment of renal tubule reabsorption leads to sodium retention, nausea, vomiting, hypertension, proteinuria, and edema, which are similar to those of hypertension during pregnancy. At the same time, severe hypertensive disorders of pregnancy can also impair liver function, renal function and coagulation function. When the HELLP syndrome develops further, its clinical manifestations and laboratory tests are very similar to AFLP. The distinction between the two must attract clinical attention. Hypoglycemia and hyperammonemia rarely occur in pre-eclampsia and HELLP syndrome during pregnancy. This is not only an important point of identification, but also a symptom of the severity of AFLP disease, indicating liver failure and poor prognosis. Ultrasound and CT examinations of the liver area are helpful for differential diagnosis, but clear diagnosis can only rely on liver biopsy. Pregnancy-induced hypertension with preeclampsia rarely causes liver failure and hepatic encephalopathy. Histological examination of the liver shows hemorrhage around the portal vein, fibrin deposition in the hepatic sinusoids, and hepatocyte necrosis. Infiltration of inflammatory cells in liver tissue and Immunohistochemical examination showed obvious staining of tumor necrosis factor (TNF) and neutrophil elastase. Sometimes the clinical manifestations of the two are very similar, and the two may coexist, making clinical identification very difficult. Because the obstetric treatment of the two is the same, both are to strengthen monitoring and early termination of pregnancy, so clinical identification is not the main contradiction.

Acute fatty liver complications during pregnancy

Stillbirth, stillbirth, preterm birth and postpartum hemorrhage are more common in AFLP. A few patients can also develop pancreatitis and hypoproteinemia.

Acute fatty liver treatment during pregnancy

General treatment

Stay in bed, give a low-fat, low-protein, high-carbohydrate diet, ensure sufficient calories, intravenous drip of glucose to correct hypoglycemia; pay attention to water and electrolyte balance, correct acidosis.

2. Blood exchange or plasma exchange

Plasma replacement therapy can remove irritating factors in the blood, supplement coagulation factors that are lacking in the body, reduce platelet aggregation, and promote vascular endothelial repair. This treatment method is widely used abroad and has achieved good results.

3. Component blood transfusion

Large amounts of frozen fresh plasma treatment can achieve similar effects to plasma exchange therapy. Red blood cells, platelets, human albumin, fresh blood, etc. can be given according to circumstances.

4. Liver protection treatment

Vitamin C, branched chain amino acid (hexavalent amino acid), adenosine triphosphate (ATP), coenzyme A, etc.

5. Adrenal corticosteroids

For short-term use to protect the renal tubular epithelium, hydrocortisone 200-300 mg intravenously should be used daily.

6. Other

According to the condition, anticoagulants and H ₂ receptor blockers are used to maintain gastric juice pH> 5 without stress ulcers. Renal failure can be treated with dialysis therapy or artificial kidney after diuresis is ineffective. Use antibiotics that have little effect on liver function, such as ampicillin, to prevent infections.

7. Obstetric treatment

Once AFLP is diagnosed or highly suspected, pregnancy should be terminated as soon as possible, regardless of the severity of the disease, sooner or later.

8. Condition treatment

The treatment time of acute fatty liver in pregnancy is closely related to the prognosis of this disease. The maternal and infant mortality rate of conservative treatment is extremely high, and liver puncture should be performed as early as possible to confirm the diagnosis. It is dangerous to perform liver puncture when there is a bleeding tendency after organ failure. After the diagnosis is made, childbirth should be given promptly and maximum supportive care should be given.

Prognosis of acute fatty liver in pregnancy

In the past 10 years, the prognosis of AFLP has improved significantly, and it is reported in the literature that it is less than 10%. The key to reducing maternal mortality is early diagnosis and timely termination of pregnancy. The symptoms of most pregnant women improved rapidly after termination of pregnancy, without obvious sequelae.

AFLP is currently thought to have recurrence. Therefore, patients with a history of AFLP must strengthen clinical and laboratory monitoring during subsequent pregnancy. In the primary and recurrent AFLP, the first symptoms are often very similar.

Early termination of pregnancy can greatly improve the prognosis of perinatal infants, and the prognosis of surviving newborns is generally considered good. Because AFLP is genetically related, newborns born to pregnant women with AFLP should be closely followed up. Whether there is a congenital liver enzyme deficiency that affects the beta-oxidizing ability of mitochondrial free fatty acids, skin fibroblast culture can confirm the diagnosis.