Clinical trial Recruiting at 1 site Phase 1 Interventional Ages 18 and up Women only

Rivaroxaban in breast milk after maternal dosing

Official title: Excretion of Rivaroxaban in Human Breast Milk

Run by Thomas Jefferson University · NCT06831474 · Data updated 2026-11-12

This will test how much rivaroxaban passes into breast milk in postpartum people taking either prophylactic (10 mg) or therapeutic (20 mg) doses.

Quick facts

PhasePhase 1
Study typeInterventional
Ages18 Years and up
SexWomen only
Enrollment10 (estimated)
SponsorThomas Jefferson University
Academic / other
Locations1 site (Philadelphia, Pennsylvania)
StatusRecruiting
StartedJuly 2025
Main results expectedApril 1, 2026
Study endsJuly 31, 2026
Registry record updatedJuly 17, 2025
Trial IDNCT06831474 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Postpartum people within six weeks of delivery, age 18 or older, hemodynamically stable, and either breastfeeding a term healthy infant or meeting criteria for prophylactic or therapeutic rivaroxaban dosing are ideal candidates.

Probably not a fit

People who are pregnant, under 18, hemodynamically unstable, or caring for preterm or medically unstable infants may not receive benefit from this study's findings.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a phase 1, single-arm trial to measure rivaroxaban concentrations in human milk after single and repeated maternal dosing at prophylactic and therapeutic levels. Participants will take oral rivaroxaban and provide serial breast milk and blood samples over time to calculate milk-to-plasma ratios and estimate relative infant dose. The trial includes postpartum people who are breastfeeding term healthy infants as well as non-breastfeeding participants meeting anticoagulation criteria. Results are intended to expand limited existing data and inform clinician counseling and guideline recommendations for postpartum anticoagulation.

Why it matters

Potential benefit: If successful, the results could give clinicians clear safety data to better counsel breastfeeding patients and help update postpartum anticoagulation guidelines.

How similar studies have gone: Existing reports on rivaroxaban in breast milk are limited but generally favorable, and this trial expands those sparse positive data by measuring both prophylactic and therapeutic dosing over time.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Postpartum within 6 weeks of delivery
2. Greater than 18 years old at expected date of delivery
3. English speaking
4. Hemodynamically stable without concern for ongoing blood loss
5. Non-breastfeeding
6. Or breastfeeding an infant born at or equal to 37 weeks' gestation, weighing \>2600g at birth and is not requiring intensive care
7. Meet inclusion criteria for prophylactic rivaroxaban dose: pre-pregnancy BMI \>/= 40 and/or any personal history of VTE. Or \>/= 2 of the following: pre-pregnancy BMI 30-39, immobility, pregnancy complications, cesarean delivery, hysterectomy
8. Or meet inclusion criteria for therapeutic rivaroxaban dose: have an indication for therapeutic anticoagulation per the American College of Obstetricians and Gynecologists' (ACOG) practice bulletin #196, or other indication per their primary team, and recommended for such anticoagulation per their primary practitioner.

Exclusion Criteria:

1. Pregnant
2. Less than 18 years old at estimated date of delivery
3. Hemodynamic instability and/or concern for ongoing blood loss
4. Newly diagnosed deep vein thrombosis (DVT) or pulmonary embolism (PE) in the postpartum period
5. Abnormal maternal renal or liver function (creatinine clearance \< 30 mL/min and/or liver function tests greater than lab normal)
6. A contraindication to rivaroxaban: hypersensitivity to rivaroxaban; active pathological bleeding
7. Breastfeeding an infant admitted to neonatal intensive care unit, infant gestational age at birth \<37w0d or weighing \<2600g.
8. If all of the following are met: age less than 40, ambulating, body mass index (BMI) less than 30, no active history of malignancy.
9. If patient lacks indication for therapeutic anticoagulation in the postpartum period per the American College of Obstetricians and Gynecologists' (ACOG) practice bulletin #196

Where it's running

  • Thomas Jefferson University Hospital
    Philadelphia, Pennsylvania, United States
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.