Clinical trial NCT04635839: Heparin Prophylaxis Dosing for Antepartum Hospitalizations (HEPDOSE)
Official title: Randomized Control Trial of Unfractionated Heparin Thromboprophylaxis Dosing for Antepartum Hospitalizations
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Pregnancy Related
Antepartum DVT
Keywords: Thromboprophylaxis
Antepartum admission
Heparin
Lead sponsor: University of California, Los Angeles
Sponsor class: OTHER
First posted: 2020-11-19
Enrollment: 46
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: This study is a randomized control trial to compare gestational age-based dosing with standard dosing of unfractionated heparin for thromboprophylaxis of hospitalized antepartum patients. The investigators aim to determine the effect of dosing on receipt of neuraxial anesthesia and pregnancy outcomes and evaluate the pharmacokinetics and pharmacodynamics of unfractionated heparin in pregnancy.

Detailed description: Venous thromboembolism is one of the leading causes of maternal morbidity and mortality, and antepartum hospitalizations place pregnant patients at an even higher risk of developing thromboembolism. As a result, there is an increased emphasis on administering pharmacologic thromboprophylaxis for antepartum patients with prolonged hospitalizations. Previously, standard dosing of unfractionated heparin was widely adopted for thromboprophylaxis in the pregnant population. However, due to a suspected altered metabolism of unfractionated heparin in pregnancy resulting in a decrease response, the American College of Obstetricians and Gynecologists (ACOG) currently recommends considering gestational age-based dosing for unfractionated heparin for thromboprophylaxis in pregnancy with standard dosing as an alternative option. The data supporting altered dosing is very limited. In addition, increased dosing of heparin may result in challenges in anesthetic management, potentially limiting the receipt of neuraxial anesthesia resulting in increased need for general anesthesia associated with both increased maternal and fetal risks. The potential effects of higher prophylactic unfractionated heparin dosing in pregnant patients need to be further explored before being widely adopted for inpatient antepartum thromboprophylaxis. The investigators propose this study to provide a direct comparison of gestational age-based unfractionated heparin dosing to standard dosing of unfractionated heparin for pharmacologic thromboprophylaxis of hospitalized antepartum patients.

Eligibility criteria: Inclusion Criteria:

* At least 18 years of age
* Speak English or Spanish
* Antepartum admission for at least 72 hours at Ronald Reagan UCLA Medical Center
* Provides informed consent for study participation

Exclusion Criteria:

* Active or threatened antenatal bleeding
* Disseminated intravascular coagulation
* Risk of imminent delivery (delivery within 12 hours)
* Thrombocytopenia (platelet count \< 100 x 109)
* Elevated baseline aPTT (\> 36.2 seconds)
* Concern for hemolysis, elevated liver enzymes, low platelet count (HELLP) syndrome
* Congenital bleeding disorders (hemophilias)
* Receiving therapeutic or prophylactic anticoagulation (unfractionated heparin, low molecular weight heparin, oral anticoagulants) for alternative indication (e.g., acquired or inherited thrombophilia, history of VTE)
* History of heparin-induced thrombocytopenia (HIT)
* SARS-CoV-2 positive
* Cognitive impairment, psychiatric instability, or language barriers that limit their ability to provide informed consent
* Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data.

Primary outcomes:
measure: Number of Participants With Elevated Serum Activated Partial Thromboplastin Time Above the Normal Range (> 36.2 Seconds).
timeFrame: Collected 6 hours after unfractionated heparin dose until patient was taken of unfractionated heparin, an average of 1 week
Secondary outcomes:
measure: Number of Participants Diagnosed With Venous Thromboembolism (Pulmonary Embolism and/or Deep Venous Thromboembolism)
timeFrame: Assessed throughout hospitalization, an average length of 8 days, until 6 weeks after delivery
measure: Number of Participants Who Did Not Receive or Had a Delay of Neuraxial Anesthesia Due to Unfractionated Heparin
timeFrame: Assessed at time of delivery
measure: Number of Participants That Received General Anesthesia
timeFrame: Assessed at time of delivery
measure: Number of Participants That Had a Delay in Timing of Delivery Due to Unfractionated Heparin
timeFrame: Assessed at time of delivery
measure: Maximum Anti-Factor Xa Level Measured
timeFrame: Collected 6 hours after unfractionated heparin dose until patient was taken of unfractionated heparin, an average of 1 week
measure: Mode of Delivery
timeFrame: Assessed at time of delivery
measure: Estimated Blood Loss From Delivery
timeFrame: Assessed at time of delivery
measure: Number of Participants That Received a Blood Transfusion
timeFrame: From time of delivery until 6 weeks after delivery
measure: Maximum Activated Partial Thromboplastin Clotting Time Levels Measured
timeFrame: Collected 6 hours after unfractionated heparin dose until patient was taken of unfractionated heparin, an average of 1 week
Other outcomes:
Locations:
city: Los Angeles
country: United States
facility: UCLA Medical Center
state: California
Study officials:
References: