What could be causing stabbing pain right below the sternum in a 37-week pregnant female?

Stabbing Pain Below Sternum at 37 Weeks Pregnancy

This stabbing substernal pain at 37 weeks requires immediate blood pressure measurement to exclude preeclampsia, which mandates delivery at this gestational age and can present with epigastric or substernal pain as a severe feature. 1, 2

Immediate Assessment Required

Check blood pressure immediately - any elevation ≥140/90 mmHg requires evaluation for preeclampsia, and severe hypertension ≥160/110 mmHg demands urgent treatment within 15 minutes to prevent maternal stroke. 2, 3

Critical Warning Signs to Assess

• Epigastric or right upper quadrant pain is a severe feature of preeclampsia indicating hepatic involvement and potential HELLP syndrome, requiring immediate delivery at ≥37 weeks regardless of blood pressure severity. 2, 3

• Associated symptoms that indicate severe preeclampsia include severe persistent headache, visual disturbances (scotomata, blurred vision), altered mental status, or nausea/vomiting. 1, 2, 3

• Labor assessment - evaluate for regular uterine contractions, cervical changes, or rupture of membranes, as substernal pain could represent referred pain from labor at term. 1, 2

Differential Diagnosis at 37 Weeks

Life-Threatening Conditions to Exclude

• Preeclampsia with severe features - substernal or epigastric pain represents hepatic capsule distension from edema or subcapsular hematoma formation, which can progress to hepatic rupture. 2, 3

• Pulmonary embolism - presents with pleuritic chest pain, dyspnea (62% of cases), and tachycardia in pregnant women, though clinical features alone cannot reliably predict PE. 4

• Cardiac causes - acute coronary syndrome or aortic dissection must be considered, though less common; pain with radiation to arm, jaw, neck or back increases concern. 5

• Placental abruption - can present with abdominal pain and uterine tenderness, occurring in 1.58% of trauma cases but also spontaneously. 6

Reassuring Features (If Present)

• Pain that varies with respiration, body position, or food intake suggests musculoskeletal or gastrointestinal origin rather than life-threatening pathology. 5

• Well-localized pain on chest wall with reproducible tenderness on palpation makes cardiac or obstetric emergency less likely. 5

Management Algorithm

If Blood Pressure ≥140/90 mmHg:

1. Immediate obstetrical consultation - preeclampsia at ≥37 weeks mandates delivery regardless of severity. 2, 3

2. Laboratory evaluation - complete blood count (platelets), liver enzymes (AST/ALT), creatinine, and urine protein-to-creatinine ratio. 1, 2, 3

3. Severe hypertension (≥160/110 mmHg) - initiate antihypertensive therapy with oral nifedipine or intravenous labetalol within 15 minutes, targeting systolic BP 110-140 mmHg and diastolic 85 mmHg. 3

4. Magnesium sulfate - administer for seizure prophylaxis if severe features present. 2, 3

If Blood Pressure Normal:

1. Assess for pulmonary embolism risk - dyspnea, tachycardia, hypoxemia, or pleuritic chest pain warrant imaging evaluation despite pregnancy. 4

2. Evaluate labor status - regular contractions, cervical examination if indicated, assess for rupture of membranes. 1

3. Consider cardiac evaluation - ECG if pain is severe, prolonged, or associated with diaphoresis, nausea, or radiation. 5

Critical Pitfalls to Avoid

• Do not assume normal blood pressure excludes preeclampsia - serious organ dysfunction can develop at relatively mild hypertension levels, and epigastric pain may be the presenting feature. 2, 3

• Do not delay delivery if preeclampsia confirmed at 37 weeks - all cases can rapidly progress to eclampsia, hepatic rupture, or other life-threatening complications. 2, 3

• Do not use D-dimer to exclude PE in pregnancy - sensitivity is only 73% in pregnant women, with documented false negatives in acute PE cases. 4

• Do not dismiss pain as "normal pregnancy discomfort" at 37 weeks - this gestational age requires heightened vigilance for preeclampsia and other complications. 1, 2

Disposition

Transfer to labor and delivery immediately if preeclampsia suspected or labor confirmed, as management must occur in a facility with obstetrical capabilities and ability to perform emergency delivery. 1, 2

Arrange urgent obstetrical evaluation even if initial assessment reassuring, given the potential for rapid deterioration of preeclampsia at term gestation. 2, 3