Management of Pregnant Patients with Right Upper Quadrant Pain

Initial Diagnostic Approach

The American College of Radiology recommends beginning with ultrasound as the initial imaging modality for any pregnant patient presenting with RUQ pain, as it is safe, readily available, and can diagnose the most common causes including acute cholecystitis, biliary disease, and identify alternative diagnoses 1, 2
Evaluate for acute cholecystitis, which is the most common diagnosable cause of RUQ pain in the general population and a significant concern in pregnancy 2
Assess vital signs carefully, particularly looking for fever, tachycardia, and tachypnea, as these combinations indicate serious complications requiring immediate attention 3
Consider the full differential diagnosis including appendicitis, urolithiasis, pancreatitis, ovarian torsion, and obstetric complications 4, 3

Ultrasound abdomen is the primary and initial imaging modality for pregnant patients with RUQ pain, with key advantages including no radiation exposure to the fetus, 96% accuracy for detecting gallstones, and the ability to identify gallbladder wall thickening, pericholecystic fluid, and sonographic Murphy sign 1, 2, 3
If ultrasound is non-diagnostic or equivocal, proceed to MRI abdomen without IV contrast, which is preferred over CT because it avoids ionizing radiation to the fetus and provides excellent soft tissue characterization 1, 5, 3

For suspected acute cholecystitis, look for US findings including gallstones, gallbladder wall thickening >3mm, pericholecystic fluid, and sonographic Murphy sign, with a sensitivity of 88% and specificity of 80% 2
If US is equivocal, consider HIDA scan (97% sensitivity, 90% specificity) or MRI/MRCP for better visualization of biliary tree and surrounding structures 1, 2
For acute cholangitis, look for the clinical triad of jaundice, fever, and RUQ pain with laboratory evidence of biliary obstruction, and US should demonstrate biliary dilatation and evidence of obstruction (stone, stricture, mass) 1

Do not delay imaging or treatment in pregnant patients with suspected acute cholecystitis or cholangitis, as complications including perforation carry significant maternal and fetal morbidity and mortality 1, 7
Do not withhold necessary CT imaging if the clinical situation is life-threatening and other modalities are non-diagnostic or unavailable, as maternal survival takes priority 3

Immediate surgical consultation is warranted for confirmed acute cholecystitis with complications (perforation, abscess, emphysematous cholecystitis), acute cholangitis requiring biliary decompression, hemodynamic instability with severe pain, or any surgical emergency identified on imaging 1, 3