Oral Board Case: Pregnancy and Appendicitis

What is your differential diagnosis for right lower quadrant pain in a pregnant patient?

Expected answer

Appendicitis is the most common non-obstetric surgical emergency in pregnancy and RLQ pain is still the most common presentation regardless of gestational age. I would also consider cholecystitis, pancreatitis, gastroenteritis, right lower lobe pneumonia, ovarian torsion, degenerating uterine myoma, pyelonephritis/UTI, round ligament pain, and obstetric causes such as preterm labor or abruption. An obstetric consult should be involved early to evaluate gynecologic and obstetric etiologies.

How does pregnancy change your interpretation of the history, exam, and labs?

Expected answer

Physiologic changes of pregnancy can mimic disease—mild tachycardia and leukocytosis can be normal, so they should not be over-weighted. The gravid uterus can displace the appendix and alter the location of pain, though RLQ pain remains most common. Peritoneal signs such as Rovsing and psoas signs are less reliable in pregnancy. Vital signs, focused labs, and serial exam remain the foundation, supplemented by urinalysis to exclude UTI and consideration of a chest x-ray to rule out pneumonia.

What is your imaging strategy, and how do you minimize fetal risk?

Expected answer

Ultrasound is the first-line imaging modality because it avoids ionizing radiation. However, it is operator dependent and the appendix is frequently not visualized, especially as gestational age advances. If ultrasound demonstrates a normal visualized appendix I continue monitoring and consider other etiologies. If the appendix cannot be visualized and there is no other pelvic pathology, I obtain MRI without gadolinium, which has no known adverse fetal effects and a high negative predictive value. I avoid CT to limit fetal radiation exposure unless there is no reasonable alternative.

MRI shows an inflamed appendix. What is the definitive management and why?

Expected answer

The treatment of appendicitis in pregnancy is appendectomy. Unlike some non-pregnant patients, non-operative antibiotic management is not currently considered appropriate in pregnancy. Early intervention—operating within 24 hours of presentation—is associated with better outcomes, so I would proceed to prompt appendectomy after preoperative antibiotics and obstetric coordination.

Open or laparoscopic appendectomy in this patient, and how do you enter safely?

Expected answer

Either open or laparoscopic is acceptable, guided by surgeon experience and the size of the gravid uterus, which limits port placement. Laparoscopy is reasonable in the second trimester. Because of the enlarged uterus, I would use an open Hasson technique rather than a Veress needle to avoid uterine injury, adjust port placement based on fundal height, and keep insufflation pressure below 12 mmHg. If peritonitis is suspected or exposure is inadequate, I would use a midline open incision.

What perioperative measures do you take to protect the fetus?

Expected answer

All patients receive preoperative antibiotics—a second-generation cephalosporin, extended-spectrum penicillin, or triple-agent therapy. At this gestational age (22 weeks, near viability), I would coordinate with obstetrics for continuous fetal monitoring during and after surgery when feasible, and consider corticosteroids for fetal lung maturity once the fetus is viable (generally 23–24 weeks). The obstetric service should be prepared for emergent cesarean delivery if indicated.

How do you counsel this patient about risks to the pregnancy?

Expected answer

I would counsel her about the increased risk of preterm delivery and fetal loss. The key determinant of fetal loss is appendiceal perforation—roughly 1.5% risk without perforation versus up to 36% with perforation—which underscores the importance of prompt appendectomy. Perforation is most likely in the third trimester. Preterm contractions are common (up to ~83%), but actual preterm labor and delivery occur in a much smaller fraction (~5–14%).

What is your postoperative management plan?

Expected answer

Continued coordination with obstetrics: fetal monitoring and surveillance for signs of preterm labor, with frequency and intensity dictated by gestational age. Tocolytic therapy may be considered by the obstetric consultants if preterm contractions occur, though it is not proven effective. Standard postoperative care includes antibiotics as indicated, pain control safe in pregnancy, and monitoring for surgical complications and abscess.