What laboratory tests are recommended in a patient with recurrent miscarriage?

Laboratory Testing for Recurrent Miscarriage

For patients with recurrent miscarriage (three or more consecutive pregnancy losses), a comprehensive panel of laboratory tests should include antiphospholipid antibodies, parental karyotyping, thyroid function tests, and complete blood count, as these address the most common treatable causes.

Essential Laboratory Tests

Immunological Testing

• Antiphospholipid antibodies 1, 2
  • Lupus anticoagulant
  • Anticardiolipin antibodies
  • Anti-β2 glycoprotein-I antibodies
  • Consider subgroup antibodies (antiphosphatidyl-serine, -inositol, -ethanolamine, -choline, -glycerol) 3

Genetic Testing

• Parental karyotype analysis 1, 2
• Cytogenetic analysis of pregnancy tissue (from third and subsequent miscarriages) 2

Endocrine Testing

• Thyroid function tests (TSH, free T4) 1, 2
• Thyroid peroxidase (TPO) antibodies 2

Hematological Testing

• Complete blood count with platelets 1, 4
• Thrombophilia screening (for second trimester losses or specific indications) 2:
  • Factor V Leiden
  • Prothrombin gene mutation
  • Protein S deficiency

Additional Tests Based on Clinical Presentation

For Suspected Thrombophilia

• Thromboelastography (TEG) - particularly if maximum amplitude (MA) ≥64 mm 1
• Sticky platelet syndrome testing 3
• Tissue plasminogen activator (TPA) levels 3
• PAI-1 levels 3

For Suspected Structural Issues

• Pelvic ultrasound (preferably 3D) 1, 2
• Hysterosalpingogram (if 3D ultrasound not available) 4

Tests Not Routinely Recommended

• Routine testing for protein C, antithrombin deficiency, and MTHFR mutation 2
• Immunological screening (HLA, cytokine, natural killer cell tests) outside research settings 2
• Infection screening (unless specific indications) 2
• Sperm DNA testing (not routinely recommended) 2

Practical Approach to Testing

1. First visit: Order antiphospholipid antibodies, thyroid function tests with TPO antibodies, and complete blood count
2. Second visit: Arrange parental karyotyping and pelvic ultrasound assessment
3. For second trimester losses: Add thrombophilia screening
4. For pregnancy tissue: Perform cytogenetic analysis when available

Important Considerations

• Testing should be performed prior to conception when possible 1
• Antiphospholipid testing must be repeated after 12 weeks if positive, as this is the most common treatable cause (found in up to 67% of cases) 3
• Parental karyotyping is especially important when pregnancy tissue shows unbalanced structural chromosomal abnormality 2
• The timing of testing is critical - some tests (like antiphospholipid antibodies) should be done when the patient is not pregnant or on hormonal therapy

By identifying specific underlying causes through appropriate laboratory testing, targeted interventions can be implemented to improve outcomes in future pregnancies, with success rates approaching 98% for certain conditions like antiphospholipid syndrome when properly treated 3.