Benefit of Risk Score-Guided Prophylaxis in Pregnant Women at Risk of Thrombotic Events: A Controlled Before-and-After Implementation Study

Abstract

Background Management of pregnant women at risk of venous thromboembolism (VTE) and placental vascular complications (PVCs) remains complex. Guidelines do not definitively specify optimal strategies. Objective Our objective was to evaluate the impact of employing risk score-driven prophylaxis strategies on VTE and PVC rates in at-risk pregnant women. Materials and Methods This study, conducted in 21 French maternity units, compared VTE and PVC rates before and after implementation of a risk scoring system to determine prophylactic strategies. Results A total of 2,085 pregnant women at risk of VTE or PVC were enrolled. Vascular events occurred in 190 (19.2%) patients before and 140 (13.0%) after implementation of risk score-driven prophylaxis (relative risk [RR] = 0.68 [0.55; 0.83]). The incidence of deep vein thrombosis during pregnancy was reduced (RR = 0.30 [0.14; 0.67]). PVC comprised mainly pre-eclampsia, occurring in 79 patients before and 42 patients after risk score implementation (RR = 0.52 [0.36; 0.75]). Post-partum haemorrhage occurred in 32 patients (3.2%) before and 48 patients (4.5%) after risk score implementation (RR = 1.38 [0.89; 2.13], p = 0.15). Conclusion Use of a simple risk scoring system, developed by experts in VTE and PVC research to guide prophylaxis, reduced the risk of thrombotic events during pregnancy without any significant increase in bleeding risk.