Safety and efficacy of adjusted-dose enoxaparin in pregnant patients with increased risk for venous thromboembolic disease

Abstract

Objective: To assess the efficacy and safety of anti-Xa guided dose-adjusted low molecular weight heparin (LMWH) thromboprophylaxis in at-risk pregnant women.

Methods: This single-center retrospective study was conducted at a quaternary hospital in Johannesburg, South Africa. We analyzed clinical and laboratory data for pregnant patients referred between January 1, 1999, and May 1, 2017, with an increased risk of venous thromboembolic disease (VTED) and treated with prophylactic LMWH adjusted according to anti-Xa levels. The efficacy endpoint was pregnancy-related VTED and/or pregnancy loss despite anti-Xa guided dose-adjusted LMWH thromboprophylaxis.

Results: We reviewed data for 113 consecutive pregnant patients with 151 pregnancies referred for prophylactic LMWH. Prevalence of pregnancy-related VTED was 1.3% (95% confidence interval [CI] 0.1-4.7), which is lower than that reported in the literature for fixed-dose thromboprophylaxis in similar at-risk groups. One venous thromboembolism event occurred in the antenatal period (despite adequate prophylaxis) and the second in the postpartum period (related to prolonged labor). Prevalence of pregnancy-related bleeding was 2% (95% CI 0.4-5.7) with all bleeding events considered to be minor and unrelated to LMWH therapy.

Conclusion: This study demonstrated the efficacy and safety of anti-Xa dose-adjusted LMWH thromboprophylaxis in at-risk pregnant patients.

Keywords: Anti-Xa adjusted enoxaparin; Pregnancy; Thromboprophylaxis.