Acute pancreatitis in pregnancy (APIP) is one of the more common surgical abdominal emergencies encountered during pregnancy. It occurs predominantly in late pregnancy and the postpartum period, with an incidence rate of 1 in 1,000 to 1 in 12,000 pregnancies, and the rate has shown an upward trend in recent years. The most common causes are lipid metabolism disorders and biliary tract diseases. Based on severity, it can be classified into mild pancreatitis and severe pancreatitis, while the pathological process can be categorized into acute edematous pancreatitis and hemorrhagic necrotizing pancreatitis. It is characterized by an acute onset, numerous complications, challenging treatment, and a high mortality rate, posing a significant threat to maternal and fetal health.
Clinical Manifestations and Diagnosis
Symptoms
Abdominal pain is the most common symptom, often triggered by high-fat meals or overeating. The pain is typically located in the left upper abdomen, can intensify paroxysmally, and may radiate to the back or shoulders. During pregnancy, the upward displacement of the uterine fundus causes the pancreas to be positioned deeper, which can lead to atypical abdominal pain symptoms. Associated symptoms may include nausea, vomiting, abdominal distension, jaundice, and fever. In severe cases, symptoms such as weak and rapid pulse, cold extremities, and other signs of shock may develop. Multi-organ failure features may occur, such as electrolyte imbalances, dyspnea, cyanosis, oliguria, gastrointestinal bleeding, and others. Severe fetal complications may result, including fetal hypoxia, stillbirth, intrauterine growth restriction, miscarriage, or preterm birth.
Physical Signs
Abdominal distension and abdominal pain often occur concurrently. In mild cases, tenderness is typically limited to the upper abdomen without significant muscular rigidity. Severe cases may present with signs such as rebound tenderness, muscle guarding, diminished or absent bowel sounds, and positive findings of ascites or peritoneal irritation, such as positive shifting dullness. Increased intra-abdominal pressure may lead to abdominal compartment syndrome. In rare severe cases, subcutaneous hemorrhagic mottling on the left flank or around the umbilicus (Grey Turner's and Cullen's signs) may appear due to retroperitoneal bleeding.
Laboratory and Imaging Studies
Amylase and Lipase Levels:
Measuring serum and urine amylase levels is the most commonly used diagnostic method. Serum amylase levels rise within hours of onset, peak at 24 hours, begin to decline after 48 hours, and normalize within 4–5 days. Urine amylase levels increase after 24 hours, peak at 48 hours, and normalize within 1–2 weeks. However, normal serum amylase levels do not rule out acute pancreatitis, as widespread pancreatic necrosis can result in a lack of amylase elevation. If necessary, peritoneal fluid analysis for amylase levels can be performed via abdominal paracentesis. Serum lipase levels typically begin to rise 24–72 hours after onset and remain elevated for 7–10 days, displaying greater specificity and sensitivity than amylase.
Imaging Studies
Ultrasound may reveal diffuse pancreatic enlargement, and areas of strong, coarse echoes or anechoic regions around the pancreas suggest exudation or hemorrhagic necrosis. However, intestinal gas may interfere with the diagnostic accuracy. Contrast-enhanced computed tomography (CT) scans can help assess pancreatic exudation, necrosis, or abscess formation. CT imaging is generally recommended after 72 hours from disease onset and may still be used if necessary, despite potential risks to the fetus. Magnetic resonance imaging (MRI) provides information comparable to CT for evaluating pancreatic necrosis, the extent of inflammation, and the presence of free gas.
Differential Diagnosis
Diagnosing pancreatitis during pregnancy can be difficult due to the relatively deep anatomical position of the pancreas and its coverage by the enlarged uterus. In early pregnancy, gastrointestinal symptoms may mimic hyperemesis gravidarum. In late pregnancy, inflammation-induced uterine contractions may be mistaken for labor. Signs such as tenderness and board-like abdomen caused by peritonitis may resemble placental abruption. Additionally, the condition should be differentiated from other diseases, including acute gastroenteritis, perforated peptic ulcer, cholecystitis, appendicitis, intestinal obstruction, and others.
Management
The management principles are generally similar to those for acute pancreatitis in non-pregnant individuals, while also requiring a multidisciplinary approach. It is essential to consider the underlying cause, gestational age, and potential impacts on the fetus during treatment. In cases without complications or organ dysfunction, conservative treatment often achieves favorable outcomes. However, for severe pancreatitis, especially when associated with impacted ampullary stones, surgical intervention to relieve the obstruction is necessary with minimal delay. For severe pancreatitis requiring debridement of necrotic tissues and adequate drainage, surgical intervention is typically recommended within 48 to 72 hours of onset.
Conservative Treatment
Conservative measures include withholding oral intake and fluids, along with continuous gastrointestinal decompression to alleviate abdominal distension and reduce intra-abdominal pressure. Intravenous fluid therapy is administered to manage and prevent shock, while providing total parenteral nutrition. Treatment focuses on maintaining water and electrolyte balance, along with anti-shock measures. Timely administration of medications to inhibit pancreatic enzymes is recommended, including somatostatin, H2 receptor antagonists, or proton pump inhibitors. For patients with hypertriglyceridemia-induced acute pancreatitis, lipid-lowering medications, lipid apheresis, or plasma exchange are utilized.
Although these medications can cross the placental barrier, their potential benefits must be weighed against risks in critically ill patients. Additional treatments include appropriate pain relief, with pethidine 50–100 mg as the first-line option, which can be combined with atropine. Morphine is contraindicated to avoid spasm of the sphincter of Oddi.
Surgical Treatment
Surgical intervention is recommended for patients with severe conditions or the following symptoms:
- Persistent peritonitis that cannot rule out other acute abdominal conditions.
- Severe biliary pancreatitis with impacted ampullary stones and biliary obstruction or infection, where early surgical relief of the obstruction is required.
- Pancreatic necrosis, significant intraperitoneal exudate, or rapid onset of multi-organ dysfunction, where surgical debridement of necrotic tissue and sufficient drainage are warranted.
- Complications such as intestinal perforation, massive hemorrhage, or pancreatic pseudocyst formation.
Obstetric Management
Acute pancreatitis in pregnancy (APIP) is not an indication for termination of pregnancy. Close fetal monitoring is required during the treatment of APIP. The timing and method of pregnancy termination depend on the severity of the maternal condition, therapeutic response, and the gestational age. Pregnancy termination is advised in any of the following scenarios:
- Severe APIP or a lack of significant improvement in the condition after treatment.
- Signs of fetal distress.
- Fetal maturity at term.
- Symptoms suggestive of inevitable miscarriage or preterm labor.