Why does preeclampsia cause epigastric pain in pregnant women?

Why Preeclampsia Causes Epigastric Pain

Epigastric pain in preeclampsia results from hepatic ischemia, edema, and distension of the liver capsule (Glisson's capsule), caused by widespread endothelial dysfunction, vasospasm, and reduced hepatic perfusion—a direct consequence of the systemic inflammatory response triggered by placental hypoperfusion and release of anti-angiogenic factors. 1, 2

Pathophysiologic Mechanism

The underlying mechanism involves a two-stage process that culminates in hepatic involvement:

Stage 1: Placental Abnormalities

• Incomplete transformation of maternal spiral arteries occurs due to shallow cytotrophoblast invasion, resulting in high-resistance uteroplacental circulation and placental hypoxia 2
• The stressed, hypoxic placenta releases excessive soluble fms-like tyrosine kinase-1 (sFlt-1) into maternal circulation, which antagonizes vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) 1, 2

Stage 2: Hepatic Manifestations

• The angiogenic imbalance leads to widespread endothelial dysfunction affecting the liver, causing hepatic ischemia and necrosis 1, 2
• Fibrin deposition within hepatic sinusoids causes sinusoidal obstruction and subsequent hepatic ischemia 3
• Activation of the coagulation cascade further compromises hepatic microcirculation 2
• Reduced hepatic perfusion causes necrosis and hemorrhage, manifesting as elevated liver enzymes and right upper quadrant/epigastric pain 1

Clinical Significance

The presence of epigastric or right upper quadrant pain in a pregnant woman after 20 weeks' gestation should immediately trigger suspicion for severe preeclampsia or HELLP syndrome, regardless of whether classic signs of preeclampsia (hypertension and proteinuria) are present. 4, 5

Key Clinical Features

• Epigastric pain results specifically from liver capsule distension due to hepatic edema and potential subcapsular hemorrhage 1, 2
• This pain is a symptom of severe preeclampsia and indicates significant hepatic involvement requiring urgent evaluation 4, 1
• 65% of symptomatic HELLP patients present with right upper quadrant or epigastric pain 3
• The pain may be accompanied by nausea and vomiting 5, 6

Critical Diagnostic Approach

All pregnant women with epigastric or right upper quadrant pain after 20 weeks' gestation must undergo immediate laboratory evaluation to rule out preeclampsia/HELLP syndrome, even in the absence of hypertension or proteinuria. 5

Essential Laboratory Tests

• Complete blood count with platelet count 4
• Liver enzymes (AST, ALT, LDH) 4, 2
• Serum creatinine and uric acid 4
• Urinalysis with protein quantification 4

Imaging Requirements

• Abdominal ultrasound should be performed in women with severe preeclampsia or HELLP syndrome if there are symptoms suggestive of hepatic hematoma, specifically abdominal, epigastric, or right shoulder pain 4, 3
• This imaging is critical because hepatic rupture carries a maternal mortality risk of 3.4% with delayed intervention 3

Common Pitfalls to Avoid

The most dangerous pitfall is attributing epigastric pain to non-obstetric causes such as gastroenterologic diseases (cholelithiasis, appendicitis) or viral hepatitis, leading to delayed diagnosis and potentially catastrophic outcomes. 5

Specific Warnings

• Classic signs of preeclampsia (proteinuria and hypertension) may be absent in 20% of HELLP syndrome cases 5
• Malaise or flu-like symptoms may be the only presenting complaint, making the diagnosis easily missed 7
• Laboratory values may remain normal until hepatic rupture has already occurred and the patient is in hypovolemic shock 8
• Clinicians should maintain high vigilance for hepatic hemorrhage or hematoma in women with HELLP syndrome and markedly reduced platelet count (<20×10⁹/L) 4

Management Implications

Once severe preeclampsia or HELLP syndrome with epigastric pain is diagnosed, prompt delivery after maternal stabilization is the definitive treatment, as delayed intervention significantly increases maternal mortality. 3, 9

Immediate Actions Required

• Initiate magnesium sulfate for seizure prophylaxis 4, 3
• Control severe hypertension urgently with antihypertensive therapy 4
• Perform abdominal imaging to rule out hepatic hemorrhage, infarct, or rupture 4, 3
• Expedite delivery once maternal coagulopathy and severe hypertension are corrected 4, 3

The degree of liver enzyme elevation correlates directly with disease severity, and the combination of thrombocytopenia with elevated liver enzymes indicates severe maternal organ dysfunction requiring immediate delivery consideration. 2