Venous thromboembolism risk score during hospitalization in pregnancy: results of 10694 prospective evaluations in a clinical trial

Objectives: Hospitalization during pregnancy and childbirth increases the risk of Venous Thromboembolism Risk (VTE). This study applied a VTE risk score to all hospitalized pregnant women to ascertain its effectiveness in pre -venting maternal death from VTE until 3 months after discharge.Methods: In this interventional study, patients were classified as low-or high-risk according to the VTE risk score (Clinics Hospital risk score). High-risk patients (score & GE; 3) were scheduled for pharmacological Thromboprophy-laxis (TPX). Interaction analysis of the main risk factors was performed using Odds Ratio (OR) and Poisson regres-sion with robust variance.Results: The data of 10694 cases (7212 patients) were analyzed; 1626 (15.2%, 1000 patients) and 9068 (84.8%, 6212 patients) cases were classified as high-risk (score & GE; 3) and low-risk (score < 3), respectively. The main risk factors (Odds Ratio, 95% Confidence Interval) for VTE were age & GE; 35 and < 40 years (1.6, 1.4-1.8), parity & GE; 3 (3.5, 3.0-4.0), age & GE; 40 years (4.8, 4.1-5.6), multiple pregnancies (2.1, 1.7-2.5), BMI & GE; 40 kg/m2 (5.1, 4.3-6.0), severe infection (4.1, 3.3-5.1), and cancer (12.3, 8.8-17.2). There were 10 cases of VTE: 7/ 1636 (0.4%) and 3/9068 (0.03%) in the high-and low-risk groups, respectively. No patient died of VTE. The inter-vention reduced the VTE risk by 87%; the number needed to treat was 3.Conclusions: This VTE risk score was effective in preventing maternal deaths from VTE, with a low indication for TPX. Maternal age, multiparity, obesity, severe infections, multiple pregnancies, and cancer were the main risk factors for VTE.