Postpartum thromboembolism: Severe events might be preventable using a new risk score model

Pelle G Lindqvist^1,3, Jelena Torsson², Åsa Almqvist¹, Ola Björgell²

¹Department of Obstetrics and Gynecology; ²Radiology, Malmö University Hospital, Lund University, Malmö, Sweden; ³Department of Obstetrics and Gynecology, Karolinska Hospital, Huddinge, Sweden

Background: Pregnancy-related venous thromboembolism (VTE) is a major cause of maternal morbidity and mortality. A new risk assessment model for VTE in relation to pregnancy has been introduced in Sweden. We wished to determine the proportion of preventable VTE cases if the model had been in use and make a brief cost-benefit analysis.

Methods: A hospital-based retrospective case-control study of all postpartum thromboembolic instances of deep venous thrombosis and pulmonary embolisms during a 16-year period. Large anamnestic risk factors at the time of delivery were assessed. We correlated the findings with the new Swedish guidelines for thromboprophylaxis.

Results: We found 37 cases of postpartum VTE during the study period. Nineteen of all VTE cases (51%) and eight out of eleven of cases of pulmonary embolism (73%) had two or more large anamnestic risk factors, ie, they would have been subjected to thromboprophylaxis if the new guidelines had been used. The cost of each preventable VTE was lower than treating a VTE.

Conclusion: Approximately one-half of postpartum VTE cases and 70% of pulmonary emboli cases have at least two large risk factors and might be preventable using the new algorithm. From the perspective of the health care system the new recommendations appears to be cost-effective.

Keywords: thromboprophylaxis, low molecular weight heparin, scoring system, health care financing, ultrasonography, phlebography