Thromboembolism in Pregnancy

Contributor: John Dacus, MD
Last Update: 5/1/2010

Deep venousthrombosis (DVT) during pregnancy

• Only 50% correctlyidentified with suspected clinical findings
• Diagnosticstudies
  • Duplex doppler ultrasoundimaging
    Proximal DVT – 98% sensitivity and 95% specificity
    Distal DVT(calf) – 50% sensitivity
    Repeat examination in 5-7 days increases sensitivity(especially calf)
  • Computerized tomography(CT) or magnetic resonance imaging (MRI) may be more helpful with pelvicthrombophlebitis or ovarian veinthrombosis.

Pulmonaryembolism during pregnancy

• Symptoms – tachypnea, tachycardia, hemoptysis, diaphoresis, fever, dyspnea,pleuritic chest pain, cough
• Diagnostic studies
  • Laboratory – arterial p 02<85mmHg. EKG with sinus tachycardia, R axis shift. Chest film.
  • 4 – channel multidetector spiral CT is the procedure ofchoice.

Treatment(Therapeutic infractionated heparin or therapeutic Lovenox ) of DVT or PulmonaryEmbolism

• Unfractionated Heparin
  • Initial IV bolus of 80U/Kg followed by 18 U/Kg to achieve a PTT of 1.5 to 2.5 normal or antifactor Xaof 0.3 to 0.7 u/ml after 24 hours.
  • Maintain IV heparin 7-10days.
  • Switch to subcutaneousheparin dosing q 12 hours to achieve a PTT of 1.5 to 2.5 times of control orantifactor Xa of 0.3 to 0.7 u/ml 6 hours after AMinjection.
• Low molecular weightheparin (Lovenox or Fragmin)
  • Lovenox 1.0 mg/kgsubcutaneous q 12 hours or Fragmin 100u/Kg q 12 hours.
  • Maintain antifactor X alevel 4 hours after AM dose to 0.5 to 1.2 u/mlrange.
• Platelet count in 7-10days after heparin begins.
• Prenatal vitamin toinsure additional Vitamin D.
• Tums with 500 mg calcium(or equivalent) 3 times per day.

References

Phelan JP. Thromboembolicdisease (chapter 19). Critical care obstetrics. Library of Congresscataloging-in-publishing data. Edited by Clark SL, Cotton DB, Hankins GD,Phelan JP. 1997; 369-398.

Compendium 2003. ACOG;633-642.

Lockwood CJ. Inheritedthrombophilia in pregnant patients: Detection and treatment paradigm. ObstetGynecol 2002;99:333-341.

Ginsberg JS, Greer I. Useof antithrombotic agents during pregnancy. Chest2001;119:1225-1315.