Appendicitis during pregnancy

By trimester

Weeks 1–13

1st trimester

Nausea and abdominal discomfort can overlap with common early-pregnancy symptoms, but focal or progressively worsening pain, fever, guarding, or persistent vomiting needs urgent assessment. Ultrasound is often the first imaging step, with MRI when ultrasound is nondiagnostic.

Weeks 14–27

2nd trimester

As the uterus enlarges, pain location may vary and cannot exclude appendicitis. MRI without contrast is commonly used after an inconclusive ultrasound, and medically necessary surgery should not be delayed because of trimester alone.

Weeks 28–birth

3rd trimester

Late-pregnancy anatomy can make examination and ultrasound more difficult. Prompt coordination among surgery, obstetrics, anesthesia, and radiology helps avoid delay while accounting for fetal monitoring and the possibility of preterm contractions.

What does the evidence show for appendicitis?

• A current clinical review describes right-lower-abdominal pain as common but not universal in pregnant patients with appendicitis; pain can be higher or in the flank, and pregnancy-related nausea or white-blood-cell elevation can blur the picture. Clinical findings alone cannot safely rule it out. 1
• A current clinical review recommends abdominal ultrasound as the initial imaging test and MRI when ultrasound is inconclusive. CT can be used when MRI is unavailable or cannot provide timely clarification, because the risk of delaying a serious surgical condition must be weighed against imaging exposure. 1
• A systematic review and meta-analysis of 19 studies estimated MRI sensitivity at 91.8% and specificity at 97.9% for appendicitis in pregnancy. These pooled results came mainly from selected patients with suspected disease and heterogeneous observational studies, not from universal pregnancy screening. 2
• The 2024 SAGES guideline conditionally favors appendectomy over nonoperative management for appendicitis during pregnancy in any trimester. Certainty is very low because evidence comes from biased observational studies and pregnant patients were excluded from major nonpregnant antibiotic-only trials. 3
• ACOG states that medically necessary surgery should not be denied or delayed during pregnancy regardless of trimester, while elective procedures should wait until after delivery. Obstetric consultation and an individualized perioperative plan are recommended because randomized pregnancy data are limited. 4

When should I call my provider about appendicitis?

Worsening or persistent abdominal pain with focal tenderness, guarding, fever, or repeated vomiting needs immediate emergency assessment during pregnancy. Fainting, confusion, rigid abdomen, severe generalized pain, rapid breathing, or marked weakness can signal rupture or sepsis. Call emergency services. Abdominal pain with vaginal bleeding, fluid leakage, regular contractions, or reduced fetal movement also requires urgent obstetric assessment because appendicitis is not the only serious possibility. If you are ever unsure which side of the line you are on, make the call. Obstetric teams handle these check-ins as routine, not as overreacting.