What are the key considerations in the management of acute appendicitis in pregnancy?

Management of Acute Appendicitis in Pregnancy

Surgical intervention is recommended when acute appendicitis is suspected in pregnancy rather than initial observation, as pregnant women are more likely to present with complicated (perforated or gangrenous) appendicitis, which carries a higher risk of fetal loss. 1, 2

Epidemiology and Clinical Presentation

• Appendicitis is the most common non-obstetric surgical emergency in pregnant women, occurring in approximately 1 in 766-1,312 pregnancies 3, 4
• Distribution by trimester:
  • First trimester: 30-32% of cases
  • Second trimester: 38-44% of cases (most common)
  • Third trimester: 16-32% of cases (least common) 5, 1

Diagnostic Challenges in Pregnancy

Clinical Assessment

• Leukocytosis is a common finding in both normal pregnancy and appendicitis, making it less reliable as a diagnostic marker 3
• Most helpful clinical findings for diagnosis:
  • Uterine contractions
  • Periumbilical pain migrating to right lower quadrant 3

Imaging Recommendations

• First-line imaging: Abdominal ultrasound 1, 2
  • High specificity but limited sensitivity
  • Safe in all trimesters
• Second-line imaging (if ultrasound is inconclusive):
  • MRI is preferred over CT to avoid radiation exposure 1, 2, 6
  • MRI has sensitivity of 96% and specificity of 97% 2

Management Approach

Surgical Management

• Laparoscopic appendectomy is the preferred surgical approach when appropriate resources and skills are available 1
• Benefits of laparoscopy compared to open appendectomy:
  • Less post-operative pain
  • Lower wound infection rates
  • Fewer early deliveries 1
• However, laparoscopy carries a slightly increased risk of fetal loss compared to open appendectomy 1

Timing of Surgery

• Prompt surgical intervention is critical to prevent perforation
• Perforation rates are significantly higher when symptoms exceed 24 hours (43% vs. 0%) 5
• Delay in diagnosis and treatment increases risk of:
  • Maternal morbidity
  • Fetal loss
  • Premature delivery 6, 7

Complications and Outcomes

Maternal Complications

• Wound infection rates are higher in perforated appendicitis (6/7 cases in one study) 5
• Overall maternal morbidity is relatively low with prompt intervention 6

Fetal Complications

• Risk of spontaneous abortion:
  • First trimester: Up to 33% following appendectomy 3
• Risk of premature delivery:
  • Second trimester: 14-33% following appendectomy 6, 3
  • Higher with both confirmed appendicitis and negative appendectomy

Key Pitfalls to Avoid

1. Delaying surgical intervention: Observation is not recommended when appendicitis is suspected due to the high risk of perforation and subsequent complications 1, 2

2. Overreliance on leukocytosis: While leukocytosis is important in making the diagnosis of appendicitis in the general population, physiologic leukocytosis of pregnancy makes this less reliable 3

3. Using CT as first-line imaging: Ultrasound followed by MRI is the recommended imaging pathway to minimize radiation exposure 1, 2

4. Dismissing appendicitis in the third trimester: Although appendicitis is least common in the third trimester, it should remain in the differential diagnosis for abdominal pain throughout pregnancy 5, 1

5. Ignoring risk of negative appendectomy: Both confirmed appendicitis and negative appendectomy carry risks of pregnancy complications, so accurate diagnosis is crucial 6

In summary, acute appendicitis in pregnancy requires prompt diagnosis and surgical intervention to minimize maternal and fetal complications. The diagnostic approach should prioritize ultrasound followed by MRI when necessary, and surgery should not be delayed when appendicitis is suspected.