Excretion of Rivaroxaban in Human Breast Milk

Eligibility 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.
• 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