Rivaroxaban vs Enoxaparin After Cesarean Section: Laboratory Thromboprophylaxis Outcomes

Pregnancy and the postpartum period increase venous thromboembolism (VTE) risk. After cesarean section, low-molecular-weight heparin (LMWH; enoxaparin) is commonly used for short-term thromboprophylaxis, but it requires daily subcutaneous injections and can cause adverse effects. Direct oral anticoagulants (DOACs) such as rivaroxaban offer convenient once-daily oral dosing. In women who meet institutional criteria for short-term postpartum thromboprophylaxis until hospital discharge, we will compare the laboratory anticoagulant effect of rivaroxaban versus enoxaparin using thrombin generation parameters. This randomized, open-label trial will enroll women undergoing elective cesarean section who are indicated for in-hospital prophylaxis. Blood will be drawn on postoperative day 2 at trough (pre-dose) and peak (\~3 hours post-dose) to measure thrombin generation, anti-Xa activity and drug levels, and participants will complete the Anti-Clot Treatment Scale (ACTS) satisfaction questionnaire. Safety follow-up will occur by telephone at 2 days post-discharge and at 6 weeks postpartum.

Inclusion Criteria: * Hebrew-speaking women * age 18-50 * Elective cesarean at Wolfson * Indicated for in-hospital thromboprophylaxis per local protocol (need ≥2 risk factors among: cesarean delivery; age \>35; BMI \>30; parity ≥3; labor duration ≥12 h; postpartum hemorrhage or blood transfusion; reduced mobility) Exclusion Criteria: * Known thrombophilia * Prior arterial/venous thrombosis * Creatinine clearance \