Evaluation and Management of Right Upper Quadrant Pain in Pregnancy

Initial Imaging Strategy

The American College of Radiology recommends starting with ultrasound of the abdomen for all pregnant patients presenting with right upper quadrant pain, regardless of clinical presentation, due to its excellent specificity, although sensitivity may be limited, particularly in later pregnancy 1, 2, 3
Ultrasound performs better in the first trimester, with appendix visualization rates of approximately 75%, declining to 37% by the third trimester, highlighting the need for a sequential approach if initial ultrasound is non-diagnostic 3
The initial ultrasound has limited sensitivity (12.5%) for appendicitis in pregnancy but maintains excellent specificity at 99.2%, emphasizing the importance of further imaging if clinical suspicion persists 1

MRI demonstrates a pooled sensitivity of 96.8%, specificity of 99.2%, and negative predictive value of 99.7% for appendicitis in pregnancy, making it a critical tool for diagnosis when ultrasound is non-diagnostic 3, 1
MRI can visualize the appendix in 70-80% of cases, significantly outperforming ultrasound, which visualizes the appendix in only 7% of cases, thereby improving diagnostic accuracy 1
MRI is also effective in identifying alternative diagnoses in 10.1-43% of cases, which is crucial given the broad differential for right upper quadrant pain in pregnancy 3, 1

The American College of Radiology and other guideline societies emphasize the importance of not delaying imaging or surgical consultation in cases of suspected appendicitis or other surgical emergencies in pregnancy, as prompt intervention can significantly reduce maternal and fetal morbidity 1, 2
Key red flags requiring immediate escalation include fever, tachycardia, signs of sepsis, hemodynamic instability, and significant leukocytosis with left shift, as these signs suggest severe infection or inflammation 2, 1
If appendicitis is confirmed, surgery should be performed within 24 hours to minimize the risk of perforation, which carries significant maternal and fetal morbidity 4

CT abdomen and pelvis should be reserved for life-threatening situations where MRI is unavailable or both ultrasound and MRI remain equivocal, due to concerns about radiation exposure, although maternal health takes absolute priority and CT should not be withheld if maternal survival is at risk 1, 2

A complete blood count with differential, comprehensive metabolic panel, liver function tests, lipase, and urinalysis with culture should be obtained to support the diagnosis, as elevated transaminases may suggest hepatobiliary pathology and pyuria indicates urinary tract infection or nephrolithiasis 2

Acute cholangitis should be suspected when right upper quadrant pain is accompanied by jaundice, fever, chills, elevated inflammatory markers, and biliary dilatation or evidence of obstruction on imaging, according to the Clinical Infectious Diseases guidelines 5

Appendicitis is the most common cause of abdominal pain requiring emergent surgery in pregnant patients, and the location of pain may not correlate with appendiceal position due to superior migration of the appendix with advancing gestation, potentially causing right upper quadrant pain in later trimesters, as recommended by the Journal of the American College of Radiology 6
Appendicitis diagnosis and management should consider the superior migration of the appendix with gestation, potentially causing right upper quadrant pain, as noted by the Journal of the American College of Radiology 7
Urolithiasis with right-sided hydronephrosis and pyelonephritis can present with right upper quadrant or right flank pain radiating anteriorly, fever, pyuria, and require differentiation from biliary disease, according to the Journal of the American College of Radiology 6

Appendicitis is the most common cause of abdominal pain that requires emergent surgery in pregnant patients; with advancing gestation the appendix migrates superiorly, so pain may present in the right upper quadrant rather than the classic right lower quadrant location. 8

Pregnant women with appendicitis are more likely to present with complicated disease (perforated or gangrenous appendicitis) compared with non‑pregnant patients. 9
Appendiceal perforation during pregnancy is associated with a higher risk of fetal loss. 10

Immediate surgical (or urologic, when appropriate) consultation is recommended for confirmed appendicitis or any surgical emergency identified on imaging in pregnant patients. 9, 10