What labs should be ordered for a postpartum patient presenting with headache and hypertension?

Laboratory Tests for Postpartum Patients with Headache and Hypertension

For a postpartum patient presenting with headache and hypertension, comprehensive laboratory testing should include urinalysis for proteinuria, complete blood count, liver function tests, serum creatinine, and uric acid levels to evaluate for preeclampsia or HELLP syndrome, which are potentially life-threatening conditions requiring immediate intervention. 1

Initial Laboratory Assessment

Essential First-Line Tests

• Urinalysis and protein quantification:

  • Dipstick test (if >1+, follow with urine protein-to-creatinine ratio)
  • Urine protein-to-creatinine ratio (UPCR) or albumin-to-creatinine ratio (UACR) 1
  • UACR <30 mg/mmol excludes significant proteinuria

• Complete blood count:

  • Hemoglobin/hematocrit (to assess for hemolysis)
  • Platelet count (thrombocytopenia is a key feature of HELLP syndrome) 1, 2

• Liver function tests:

  • AST/ALT (elevated in preeclampsia and HELLP syndrome)
  • LDH (marker for hemolysis) 1

• Renal function assessment:

  • Serum creatinine
  • Electrolytes (sodium, potassium)
  • Serum uric acid (associated with worse outcomes though not diagnostic) 1

Second-Line Tests Based on Initial Findings

If initial tests suggest preeclampsia or other complications:

• Coagulation studies:

  • PT/INR and PTT (to assess for disseminated intravascular coagulation) 2
  • Fibrinogen levels

• Additional blood tests:

  • Blood smear (to evaluate for schistocytes/hemolysis)
  • Serum albumin (may be decreased in preeclampsia)

Imaging Studies When Indicated

Neuroimaging should be considered in patients with:

• Severe, persistent headache despite treatment
• Focal neurologic deficits
• Seizures
• Altered mental status
• Headache refractory to usual therapy 3

Appropriate imaging may include:

• CT or MRI of the brain (to rule out hemorrhage, thrombosis, or vasculopathy)
• MR angiography (if reversible cerebral vasoconstriction syndrome is suspected) 4

Clinical Considerations

Timing of Presentation

• Postpartum preeclampsia can present from 3-10 days after delivery (median 5 days) 5
• Over half of postpartum preeclampsia cases (55%) have no prior diagnosis of preeclampsia during pregnancy 5

Warning Signs Requiring Urgent Assessment

• Severe headache with hypertension is a concerning combination that may precede seizures 2, 3
• Visual changes accompanying headache increase risk of serious complications 5
• Abdominal pain may indicate liver involvement in HELLP syndrome 2

Blood Pressure Measurement Technique

• Measure BP in sitting position with back supported, legs uncrossed
• Use appropriate cuff size (large cuff for arm circumference ≥33 cm)
• Allow 5 minutes of rest before measurement 6

Diagnostic Algorithm

1. Immediate assessment:

   • Check BP using proper technique
   • Evaluate for proteinuria (dipstick followed by quantification)
   • Order CBC, liver enzymes, creatinine, and uric acid

2. If laboratory abnormalities present:

   • Elevated liver enzymes + low platelets: Consider HELLP syndrome
   • Proteinuria + hypertension: Diagnose preeclampsia
   • Normal labs but persistent symptoms: Consider additional testing

3. For severe or atypical headache:

   • Proceed with neuroimaging to rule out cerebral hemorrhage, thrombosis, or vasculopathy 3

Remember that postpartum headache with hypertension requires thorough evaluation as it may indicate life-threatening conditions including preeclampsia, eclampsia, or intracranial pathology 3. Early detection through appropriate laboratory testing is critical to prevent serious maternal morbidity and mortality.