Efficacy and safety of venous thromboembolism prophylaxis with fondaparinux in women at risk after cesarean section

Cesarean section is associated with an increased risk for venous thromboembolism (VTE). The safety and efficacy of primary prophylaxis of fondaparinux, a synthetic sulfated pentasaccharide heparin analog, in women at risk after cesarean section is uncertain.

This was a retrospective study of 295 cases of pregnant women presenting to a tertiary referral center of Nara, Japan, to evaluate the usefulness of thromboprophylaxis with fondaparinux after cesarean delivery between 2011 and 2012. Patients were initially received unfractionated heparin (once 5,000 IU subcutaneously, twice a day), starting 6 hours after cesarean section for 24 hours, and then treated with fondaparinux (once 2.5 mg daily, subcutaneously) for 5 days. The primary efficacy end-point was an improvement in the incidence of symptomatic VTE or fatal post-cesarean pulmonary thromboembolism. The primary safety end-point was major bleeding during treatment.

There were neither any episodes of symptomatic VTE cases nor maternal deaths. A total of 10 patients had a bleeding event. Major bleeding complication was observed in 2 (0.68%) of 295 patients receiving fondaparinux. Non-major bleeding into critical sites was observed in 8 patients, often at surgical sites, and recovery was not delayed.

This study demonstrates the safety and efficacy of fondaparinux in women at high risk of VTE after cesarean section. Large phase trials comparing clinical outcomes with fondaparinux across a wide spectrum of patients are needed to confirm these observations.