What is the management approach for a pregnant woman in her 5th month of gestation presenting with abdominal pain?

Management of Abdominal Pain in 5th Month of Pregnancy

The immediate priority is to systematically rule out life-threatening obstetric and surgical emergencies through clinical assessment and ultrasound imaging, as the 5th month (second trimester) represents the optimal window for surgical intervention if needed. 1

Initial Clinical Assessment

Assess hemodynamic stability first by checking vital signs—tachycardia, hypotension, and tachypnea signal serious maternal-fetal compromise requiring immediate intervention. 2 Evaluate for:

• Peritoneal signs (guarding, rigidity, rebound tenderness) suggesting surgical emergency 2
• Vaginal bleeding indicating potential placental or pregnancy complications 1, 2
• Pain characteristics: location, severity, radiation, timing, and associated symptoms 3
• Fever with abdominal pain suggesting infection requiring urgent evaluation 3

Establish IV access immediately if any instability is present. 2

Critical Differential Diagnoses to Exclude

Obstetric Emergencies

• Ectopic pregnancy (though less likely at 5 months, abdominal pregnancy remains possible and life-threatening) 4, 5, 6
• Threatened abortion or placental abnormalities presenting with cramping pain and bleeding 3

Surgical Emergencies (Non-Obstetric)

Appendicitis is the most common cause of abdominal pain requiring emergency surgery in pregnancy and presents atypically due to anatomical displacement by the gravid uterus. 1, 2, 3 The appendix migrates superiorly as pregnancy progresses, making diagnosis challenging. 3

Gallstone disease is the second leading cause (after appendicitis) of nonobstetric acute abdominal pain during pregnancy. 1 Conservative management leads to recurrent symptoms in 60% of patients and increased hospitalizations. 1

Other critical diagnoses include:

• Ovarian torsion causing acute pain 3, 7
• Urolithiasis and pyelonephritis 3, 7
• Acute cholecystitis and pancreatitis 1, 7
• Internal herniation (especially in post-bariatric surgery patients, with 9% maternal and 13.6% fetal mortality) 2, 3

Diagnostic Imaging Algorithm

Start with ultrasound as the primary imaging modality for all pregnant patients with abdominal pain. 3, 8 This includes:

• Obstetric ultrasound to assess fetal viability, placental location, and amniotic fluid 2
• Targeted ultrasound for suspected gallbladder disease, appendicitis, or ovarian pathology 3, 7

If ultrasound is inconclusive, proceed to MRI without contrast as the next step. 2, 3 MRI provides excellent soft tissue detail without radiation and has 97% sensitivity and 95% specificity for diagnosing appendicitis in pregnancy. 2, 7

Reserve CT with IV contrast for life-threatening situations only when diagnosis cannot be made by ultrasound or MRI and immediate intervention is needed. 2, 3 A single-acquisition CT delivers <25 mGy, posing minimal fetal risk when maternal or fetal life is threatened. 2

Management Strategy by Diagnosis

For Gallstone Disease

Laparoscopic cholecystectomy is the standard of care and safe during pregnancy, ideally performed in the second trimester (which includes the 5th month). 1 Key evidence:

• Conservative management results in 60% recurrence rate and increased hospitalizations 1
• Same-admission cholecystectomy reduces 30-day readmission by 85% in biliary pancreatitis 1
• No significant difference in premature delivery or abortion rates with surgery 1
• Laparoscopy can be performed safely during any trimester according to Society of American Gastrointestinal and Endoscopic Surgeons guidelines 1

Position the patient in left lateral or partial left lateral decubitus position to minimize inferior vena cava compression. 1

For Appendicitis

Surgical intervention should not be delayed when appendicitis is diagnosed, as maternal and fetal outcomes worsen with delayed treatment. 2, 3 Laparoscopic surgery is safe in the second trimester and preferred over open surgery when feasible. 3

For Other Surgical Pathology

Do not delay surgical consultation or intervention for ovarian torsion, cholecystitis, or suspected internal herniation. 2, 3 Maternal and fetal deaths have been reported when treatment is delayed beyond 48 hours in internal herniation cases. 3

Critical Pitfalls to Avoid

• Never attribute severe abdominal pain to "normal pregnancy changes" without excluding serious pathology first 2, 3
• Do not delay imaging or surgical consultation due to radiation concerns—maternal and fetal outcomes worsen with delayed treatment 2, 3
• Do not assume ultrasound excludes all pathology—ultrasound sensitivity for some conditions (like placental abruption) is only 40-50% 2
• Remember the second trimester is the optimal surgical window—elective surgery is ideally performed now to reduce risk of spontaneous abortion (first trimester) and preterm labor (third trimester) 1

Laboratory Studies

Obtain complete blood count, urinalysis, and coagulation profile as baseline studies. 3, 7 Check fecal calprotectin if inflammatory bowel disease is suspected (cutoff 200 mg/mg has 67-74% positive predictive value for disease activity). 1