Management of Pregnant Patients with Right Lower Quadrant Pain

Initial Diagnostic Approach

The American College of Radiology recommends beginning with ultrasound as the initial imaging modality, followed by MRI without IV contrast if ultrasound is non-diagnostic, reserving CT only for life-threatening situations where other modalities are unavailable or inconclusive 1, 2, 3, 4

The American College of Radiology suggests that ultrasound abdomen is the mandatory initial imaging study for all pregnant patients with RLQ pain, with a sensitivity of 12.5% and specificity of 99.2% for appendicitis in pregnancy 1, 2, 3, 4
The American College of Radiology recommends that if ultrasound is non-diagnostic or equivocal, proceed immediately to MRI abdomen and pelvis without IV contrast, which demonstrates superior diagnostic performance with pooled sensitivity of 96.8%, specificity of 99.2%, accuracy of 99.0%, PPV of 92.4%, and NPV of 99.7% 1, 2, 4
MRI visualizes the appendix in 70-80% of cases compared to only 7% with ultrasound, and identifies alternative diagnoses in 10.1-43% of cases 1, 2, 3, 4
A sequential approach using ultrasound followed by MRI for non-diagnostic cases achieves sensitivity of 100%, specificity of 98.3%, PPV of 80%, and NPV of 100% 2, 4

The American College of Radiology advises against delaying imaging or surgical intervention in pregnant patients with suspected appendicitis, as perforation carries significant maternal and fetal morbidity and mortality 6
Immediate surgical consultation is warranted for confirmed appendicitis, hemodynamic instability, or any surgical emergency identified on imaging 6

The American College of Radiology recommends that CT abdomen and pelvis should be reserved for situations where MRI is unavailable or results remain equivocal after both ultrasound and MRI, and that low-dose CT with oral contrast can be considered when MRI is not immediately available 1, 2
The American College of Radiology states that maternal health takes absolute priority, and CT imaging should not be withheld if the clinical situation is life-threatening and maternal survival is at risk 6