Appendectomy for suspected appendicitis during pregnancy- a retrospective comparative study of 99 pregnant and 1796 non-pregnant women.

Introduction: Suspected appendicitis is the most common indication for non-obstetric surgery during pregnancy. Diagnosis and management of these patients can be challenging. Atypical clinical presentation has been described before, but the current literature consists mostly of small case series. Therefore, we conducted a large retrospective study to analyze the frequency and diagnostic accuracy of clinical signs, laboratory findings and imaging modalities in pregnant woman undergoing surgery for suspected appendicitis compared to a control group of non-pregnant women of childbearing age. We further describe intra- and postoperative findings in both groups.

Methods: Data from consecutive patients who underwent appendectomy for suspected appendicitis during pregnancy were retrieved from the electronic patient database and analyzed. Preoperative clinical, laboratory and imaging findings as well as intra- and postoperative characteristics were compared between pregnant and non-pregnant women.

Results: Between January 2008 and June 2023, 99 pregnant woman and 1796 non-pregnant woman between the ages of 16 and 49 underwent emergency surgery for suspected appendicitis. Pregnant women were less likely to have right lower quadrant tenderness (p = 0.002), guarding (p = 0.011) and rebound tenderness (p = 0.097). A greater percentage of pregnant women had a symptom duration of more than 24 h before presentation (p = 0.003) Abdominal ultrasound showed a reduced diagnostic accuracy in pregnant women (p = 0.004). MRI was used in eight pregnant women and showed a diagnostic accuracy of 100%. Pregnant women had a longer operating time (p = 0.006), a higher rate of open appendectomies or conversion (p < 0.001) and a longer postoperative hospital stay (3.2 days vs. 2.2 days, p < 0.001). The perforation rate was also higher in pregnant women at 16% vs. 10% (p = 0.048).

Conclusion: The diagnosis of acute appendicitis during pregnancy presents a challenge for the clinician. Our data confirm the paradigm of "atypical presentation" which should lead to an extended diagnostic workup. Ultrasound showed less diagnostic accuracy in pregnant women in our study. MRI is a useful tool to reduce uncertainty and the rate of negative appendectomies.