This pregnant patient's fever, right-sided abdominal pain, and leukocytosis are concerning for possible acute appendicitis. Pregnant patients with acute appendicitis can have a typical presentation (eg, anorexia, periumbilical pain that migrates to the right lower quadrant). However, due to the displacement of the appendix by the growing uterus during pregnancy, atypical presentations are common. The upward displacement of the appendix results in decreased contact between the appendix, parietal peritoneum, and omentum. Therefore, patients often have no peritoneal signs (eg, no rebound or guarding) and no McBurney point tenderness.
Patients with atypical presentations require imaging; first-line imaging during pregnancy is a graded compression abdominal ultrasound due to the low risk of radiation exposure to the fetus. When ultrasound findings are inconclusive, an abdominal MRI is indicated.
Appendicitis diagnosed and treated prior to perforation has no associated obstetric complications. However, the atypical presentation during pregnancy can result in delayed diagnosis, thereby increasing the risk for appendiceal perforation. Appendiceal perforation increases the risk for spontaneous abortion, preterm labor, and preterm delivery.
A CT scan is the first-line imaging modality for appendicitis in nonpregnant patients; however, it is avoided during pregnancy due to the risk of fetal radiation exposure. If an ultrasound is nondiagnostic and an MRI is unavailable, a CT scan can be performed.