Rivaroxaban vs Enoxaparin After Cesarean Section: Laboratory Thromboprophylaxis Outcomes

NCT07820670 | Recruiting

• 1 other identifier: 0085-25-WOMC
• Study Type: interventional
• Target: 62
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Postpartum Period; Cesarean Section Surgery; VTE (Venous Thromboembolism)

Keywords

Rivaroxaban; Enoxaparin; LMWH; DOAC; Thromboprophylaxis; Thrombin Generation; Endogenous Thrombin Potential; Post-cesarean

Outcome Measures

Primary Outcomes (1)

• Endogenous Thrombin Potential (ETP)

  Between-group comparison of ETP to assess similarity of anticoagulant effect; lower ETP indicates greater anticoagulation.

  Postoperative day 2: immediately before the study drug dose (trough) and approximately 3 hours after the study drug dose (peak), during the index hospitalization

Secondary Outcomes (6)

• Thrombin Generation - Lag Time (minutes)

  Postoperative day 2: immediately before the study drug dose (trough) and approximately 3 hours after the study drug dose (peak), during the index hospitalization

• Thrombin Generation - Peak Thrombin (nM)

  Postoperative day 2: immediately before the study drug dose (trough) and approximately 3 hours after the study drug dose (peak), during the index hospitalization

• Anti-Xa activity (IU/mL) - Enoxaparin arm

  Postoperative day 2: immediately before the enoxaparin dose (trough) and approximately 3 hours after the enoxaparin dose (peak), during the index hospitalization

• Plasma Rivaroxaban Concentration (ng/mL) - Rivaroxaban arm

  Postoperative day 2: immediately before the rivaroxaban dose (trough) and approximately 3 hours after the rivaroxaban dose (peak), during the index hospitalization

• Treatment Satisfaction (ACTS Questionnaire total and subscales)

  Postoperative day 2, prior to hospital discharge

Study Arms (2)

Rivaroxaban

EXPERIMENTAL

Participants receive rivaroxaban 10 mg orally (PO) once daily, starting ≥12 hours after cesarean delivery and ≥6 hours after spinal anesthesia, and continuing once daily during the index hospitalization until discharge. Standard postpartum care is provided to all participants.

Drug: Rivaroxaban

Enoxaparin

ACTIVE COMPARATOR

Participants receive enoxaparin 40 mg subcutaneously (SC) once daily, starting ≥12 hours after cesarean delivery and ≥6 hours after spinal anesthesia, and continuing once daily during the index hospitalization until discharge. Standard postpartum care is provided to all participants

Drug: Enoxaparin 40 mg

Interventions

Rivaroxaban DRUG

10 mg PO once daily from ≥12 h post-C-section until discharge

Also known as: Xarelto

Rivaroxaban

Enoxaparin 40 mg DRUG

40 mg SC once daily from ≥12 h post-C-section until discharge

Also known as: Clexane

Enoxaparin

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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)

You may not qualify if:

• Known thrombophilia
• Prior arterial/venous thrombosis
• Creatinine clearance \<29 mL/min
• Abnormal liver enzymes/bilirubin or liver disease
• Coagulation disorders
• Platelets \<75,000/mm³
• Interacting drugs affecting DOAC metabolism (e.g., strong CYP3A4/P-gp modulators; azoles; protease inhibitors; rifampicin; phenytoin; carbamazepine; phenobarbital; St. John's wort; dronedarone)
• Active bleeding or contraindication to anticoagulation
• Peptic disease/GI bleeding history
• Hemoptysis risk/history
• Preeclampsia
• Active infection
• Significant lower-limb varicosities
• Need for prophylaxis beyond discharge (≥3 risk factors)
• Maternal weight \<50 kg or \>100 kg

Sponsors & Collaborators

• Wolfson Medical Center: lead

Study Sites (1)

Edith Wolfson Medical Center

Holon, 6997107, Israel

RECRUITING

Related Publications (7)

• Cano SJ, Lamping DL, Bamber L, Smith S. The Anti-Clot Treatment Scale (ACTS) in clinical trials: cross-cultural validation in venous thromboembolism patients. Health Qual Life Outcomes. 2012 Sep 26;10:120. doi: 10.1186/1477-7525-10-120.

  PMID: 23013426 RESULT

• Cohen H, Dore CJ, Clawson S, Hunt BJ, Isenberg D, Khamashta M, Muirhead N; RAPS Trial Protocol Collaborators. Rivaroxaban in antiphospholipid syndrome (RAPS) protocol: a prospective, randomized controlled phase II/III clinical trial of rivaroxaban versus warfarin in patients with thrombotic antiphospholipid syndrome, with or without SLE. Lupus. 2015 Sep;24(10):1087-94. doi: 10.1177/0961203315581207. Epub 2015 May 4.

  PMID: 25940537 RESULT

• Eerenberg ES, Kamphuisen PW, Sijpkens MK, Meijers JC, Buller HR, Levi M. Reversal of rivaroxaban and dabigatran by prothrombin complex concentrate: a randomized, placebo-controlled, crossover study in healthy subjects. Circulation. 2011 Oct 4;124(14):1573-9. doi: 10.1161/CIRCULATIONAHA.111.029017. Epub 2011 Sep 6.

  PMID: 21900088 RESULT

• Guyatt GH, Akl EA, Crowther M, Gutterman DD, Schuunemann HJ; American College of Chest Physicians Antithrombotic Therapy and Prevention of Thrombosis Panel. Executive summary: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012 Feb;141(2 Suppl):7S-47S. doi: 10.1378/chest.1412S3. No abstract available.

  PMID: 22315257 RESULT

• Chan NC, Eikelboom JW, Weitz JI. Evolving Treatments for Arterial and Venous Thrombosis: Role of the Direct Oral Anticoagulants. Circ Res. 2016 Apr 29;118(9):1409-24. doi: 10.1161/CIRCRESAHA.116.306925.

  PMID: 27126650 RESULT

• Greer IA, Nelson-Piercy C. Low-molecular-weight heparins for thromboprophylaxis and treatment of venous thromboembolism in pregnancy: a systematic review of safety and efficacy. Blood. 2005 Jul 15;106(2):401-7. doi: 10.1182/blood-2005-02-0626. Epub 2005 Apr 5.

  PMID: 15811953 RESULT

• Stein PD, Hull RD, Kayali F, Olson RE, Alshab AK, Meyers FA, Ghali WA, Silbergleit A, Gibson P. Venous thromboembolism in pregnancy: 21-year trends. Am J Med. 2004 Jul 15;117(2):121-5. doi: 10.1016/j.amjmed.2004.02.021. No abstract available.

  PMID: 15234649 RESULT

MeSH Terms

Conditions

Venous Thromboembolism

Interventions

Rivaroxaban; Enoxaparin

Condition Hierarchy (Ancestors)

Thromboembolism; Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Thiophenes; Sulfur Compounds; Organic Chemicals; Morpholines; Oxazines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heparin, Low-Molecular-Weight; Heparin; Glycosaminoglycans; Polysaccharides; Carbohydrates

Study Officials

• Amihai Rottenstreich, MD

  Wolfson Medical Center

  PRINCIPAL INVESTIGATOR

• Ilia Kleiner, MD

  Wolfson Medical Center

  STUDY DIRECTOR

• Noa Gonen, MD

  Wolfson Medical Center

  STUDY DIRECTOR

• Hagit Eisenberg, MD

  Wolfson Medical Center

  STUDY DIRECTOR

Central Study Contacts

Or Marom, MD

CONTACT

+972-52-554-0490; orr.marom@gmail.com

Hagit Eisenberg, MD

CONTACT

+972-52-3397843; hagiteisen@yahoo.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Obstetrics and Gynecology Resident Physician

Study Record Dates

• First Submitted: September 1, 2026
• First Posted: September 15, 2026
• Study Start: December 1, 2025
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: September 15, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE
• Time Frame: Data and supporting documents will be available starting 6 months after publication of the primary results (or 12 months after primary completion, whichever occurs first) and will remain available for 5 years thereafter.
• Access Criteria: Qualified researchers affiliated with academic or healthcare institutions may request access by emailing the Principal Investigator (contact listed in this record) with a brief proposal (objectives, methods, variables requested, analysis plan) and documentation of local IRB/ethics approval or exemption. Requests will be reviewed within \~30 days by the study investigators for methodological soundness and consistency with participant consent. Approved requestors must sign a Data Use Agreement (DUA) specifying: use only for the approved purpose; no re-identification or contact of participants; no onward sharing; secure data storage; prompt reporting of breaches; and publication transparency (cite this study and share analytic code upon publication). Data will be transferred via secure encrypted file exchange (or read-only secure environment) after DUA execution.

Locations

IL (1)