Objectives: To review the scientific evidence on the risk and prevention of venous thromboembolic disease (VTD) associated with specific clinical factors in women.
Study design: Qualitative systematic review.
Data source: MEDLINE, Cochrane library, clinical practice guidelines, and referenced articles from these sources.
Results: Gender is not an independent risk factor of VTD. Absolute risks associated with each circumstance (per 1000 women-year) were: pregnancy, 1.23; puerperium, 3.2; pregnancy in thrombophilic, 40; pregnancy and background of previous VTD, 110; use of third generation contraceptives, 0.3; postcoital pill, no risk; hormone replacement therapy, 0.2-5.9; tamoxifen, 3.6-12; and raloxifene, 9.5. The quality of the evidence on risk was classified as good or excellent. Evidence on prevention was scarce. Screening for thrombophilia prior to the prescription of contraceptives is not cost-effective as a strategy for prophylaxis. Use of low molecular weight heparin (LMWH) in high-risk pregnancies is supported by medium quality studies.
Conclusions: There is good quality evidence on the magnitude of VTD risk associated with specific clinical factors in women. No studies on the utility of preventive measures have been performed for most of these circumstances. There is no evidence about the risk associated with the combination of several risk factors.