Pregnancy and heparin: low-risk of vertebral fractures and bleeds

Clinical bottom line (level 4)

  1. Pregnant women who take thromboprophylaxis are at low risk for vertebral fractures (2%) and bleeds (1%).
Dahlman : American Journal of Obstetrics and Gynecology 1993; 168 (4): 1265-1270
Expires June 2003

The study

Case series with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, Sweden

184 patients (aged ?, 100% female) pregnant women
Long-term subcutaneous heparin. 48 high-risk patients (mechanical heart valve, recurrent venous thromboembolism, VTE and coagulation disorder), received heparin so that anti-factor Xa 0.1 to 0.2 IU/ml (average of 25,000 units per day). 136 low-risk (VTE without risk factors), received heparin so anti-factor Xa 0.08 to 0.15 IU/ml (average of 16,5000 units per day).

100% followed for until end of pueperium
Outcomes studied:
  • vertebral fractures
  • bleeds
  • venous thromboembolism

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    vertebral fractures until end of pueperium 4/184 2.17%
    (0.067% to 4.28%)
    bleeds until end of pueperium 2/184 1.09%
    (0.00% to 2.59%)
    venous thromboembolism until end of pueperium 5/184 2.72%
    (0.37% to 5.07%)

    • 2 patients had major bleeds (both while on I/V heparin and undergoing C/S).

    Comments

    1. LMWH are now more commonly used and may have fewer risks.

    Citation

    1. Dahlman TC, : Osteoporotic fractures and the recurrence of thromboembolism during pregnancy and the puerperium in 184 women undergoing thromboprophylaxis with heparin. American Journal of Obstetrics and Gynecology 1993; 168 (4): 1265-1270
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: Paul Flynn

    Clinical Question.
    Patient pregnant
    Intervention or Exposure long-term heparin
    Outcome fractures and bleeding