VTE in pregnancy and puerperium

• Venous Thromboembolism (VTE) encompasses two related conditions:
  • Deep Vein Thrombosis (DVT), which is a clot in a deep vein, typically in the legs.
  • Pulmonary Embolism (PE), a potentially life-threatening condition where a clot breaks off and travels to the lungs.
• Pregnancy and the puerperium (the period immediately after childbirth) are times of increased risk for VTE due to physiological changes in coagulation.

VTE occurs in approximately 1-2 per 1,000 pregnancies, making it a leading cause of maternal morbidity and mortality in the developed world.

• Pregnancy induces a hypercoagulable state through increased levels of clotting factors, decreased fibrinolysis, and venous stasis, partly due to the compression of the inferior vena cava by the enlarging uterus.
• These changes facilitate the formation of blood clots, increasing the risk of VTE.

• Previous VTE.
• Thrombophilia (hereditary or acquired).
• Advanced maternal age (>35 years).
• Obesity (BMI >30 kg/m²).
• Smoking.
• Multiparity.
• Caesarean delivery.
• Prolonged immobilisation.
• IVF conception.
• Medical conditions such as systemic lupus erythematosus (SLE) or sickle cell disease.
• Dehydration.

• DVT:
  • Swelling, pain, warmth, and redness in the affected leg.
  • Palpable cord may be present along the vein.
• PE:
  • Sudden shortness of breath.
  • Chest pain, which may worsen with deep breathing.
  • Rapid heart rate.
  • Coughing up blood.

• DVT:
  • Compression ultrasonography is the first-line diagnostic test.
  • D-dimer levels may be elevated in pregnancy, reducing their diagnostic utility.
• PE:
  • Chest x-ray as an initial investigation to rule out other causes of symptoms.
  • CT pulmonary angiography (CTPA) is the preferred diagnostic modality for suspected PE if the patient is haemodynamically stable.
  • Ventilation-perfusion (V/Q) scan may be considered if CTPA is contraindicated.

• Anticoagulation:
  • Low molecular weight heparin (LMWH) is the preferred anticoagulant in pregnancy due to its safety profile.
  • LMWH does not cross the placenta and has a lower risk of osteoporosis and heparin-induced thrombocytopenia (HIT) compared to unfractionated heparin.
  • Warfarin is contraindicated during pregnancy due to teratogenic effects but can be used during the puerperium.
• Duration:
  • Anticoagulation treatment typically continues throughout pregnancy and for at least 6 weeks postpartum, totalling at least 3 months of therapy.

• Risk assessment for VTE should be performed early in pregnancy and during the postpartum period.
• Prophylactic LMWH may be recommended for women with high-risk conditions.
• Mechanical prophylaxis (e.g., graduated compression stockings) may be considered when anticoagulation is contraindicated.
• Postpartum Care:
  • Women with a history of VTE or thrombophilia should have a tailored postpartum anticoagulation plan.
  • Breastfeeding women can safely use LMWH or warfarin.

• VTE in pregnancy and the puerperium represents a significant risk to maternal health.
• Careful risk assessment, prompt diagnosis, and appropriate management are required to prevent serious complications.
• Understanding the unique aspects of VTE in this population, including the physiological changes during pregnancy that contribute to the increased risk, the safe use of anticoagulants, and the importance of individualised prevention strategies, is crucial for medical students and healthcare professionals involved in obstetric care.