Introduction

Appendicitis is the most common surgical emergency during pregnancy. It accounts for 25 per cent of surgeries for non-obstetric causes. The incidence is around 1/766 live births.^{1, 2}

Although it can occur at any time during pregnancy or postpartum period, it most commonly occurs in the second trimester.

Complication rate is higher if presented in the third trimester due to the delay in diagnosis and the decision on surgery which increases the rate of appendix rupture.

Clinical Presentation

A high level of suspicion is required as there is a wide range of symptoms and the laboratory tests cannot be used as diagnostic in pregnancy.

1. 
   

   1. A new onset of abdominal pain in pregnancy should be alerting.

   
   

   The most common instance is diffuse abdominal or periumbilical pain migrating to the right lower abdomen.

   
   

   The gravid uterus will push the appendix cephalad, so the pain will be felt at the upper abdomen in 55 per cent of cases; sometimes it can be subcostal.

   
   

   Pain may be felt in the right iliac fossa, in the right upper quadrant or mid-epigastric.

   
   
2. 
   

   2. Rectal pain is common in the first trimester.

   
   
3. 
   

   3. Anorexia, nausea and vomiting may start after the onset of pain.

   
   
4. 
   

   4. Fever up to 101.0°F (38.3°C) may develop later.

   
   
5. 
   

   5. Leucocytosis develops later³ but it is inconclusive as up to 16 000 cells/mL is considered normal in pregnancy and up to 30 000 cells/mL is accepted during labour.

   
   

   Non-specific symptoms like dysuria and diarrhoea are common. Tachycardia is common in pregnancy and cannot be used to favour the diagnosis of acute appendicitis.

   
   

   C-reactive protein (CRP) is of no clinical significance in pregnancy.

On Clinical Examination

1. 
   

   1. Tender McBurney point

   
   
2. 
   

   2. Rebound tenderness

   
   
3. 
   

   3. Guarding

   
   
4. 
   

   4. Positive psoas or Rovsing’s sign; if palpation of the left lower quadrant of the abdomen increases the pain felt in the right lower quadrant, the patient is said to have a positive Rovsing’s sign and may have appendicitis³

   
   
5. 
   

   5. Rectal/pelvic tenderness

   
   
6. 
   

   6. Appendicular lump may be felt

   
   
7. 
   

   7. Decreased bowel sounds

Differential Diagnosis⁴

1. 
   

   1. Gastrointestinal, e.g. gastroenteritis, mesenteric adenitis, pancreatitis, bowel obstruction and cholecystitis

   
   
2. 
   

   2. Urinary tract, e.g. infections, pyelonephritis and nephrolithiasis

   
   
3. 
   

   3. Gynaecological, e.g. ovarian cyst accidents, adnexal torsion, degenerated fibroid, ectopic pregnancy

   
   
4. 
   

   4. Obstetric, e.g. placental abruption and chorioamnionitis

   
   
5. 
   

   5. Musculoskeletal pain, e.g. rectus haematoma, usually has gradual onset

Fetal Implications

Untreated appendicitis or delay in treatment may lead to:

1. 
   

   1. Miscarriage

   
   
2. 
   

   2. Preterm labour

   
   
3. 
   

   3. Perinatal mortality

In a retrospective single-centre study of 102 cases of pregnant women who were diagnosed and managed for acute appendicitis, the fetal prognosis differed according to the delay in treatment and the occurrence of perforation with a significant difference. The rate of preterm labour was 5.1 per cent vs 1.3 per cent and the rate of fetal mortality was 25 per cent vs 1.7 per cent between patients with and without a perforated appendix.⁸ [EL 2]