Heparin Prophylaxis Dosing for Antepartum Hospitalizations (HEPDOSE)

Phase 4

Completed

• Conditions: Pregnancy Related; Antepartum DVT
• Interventions: Drug: Standard Dose of Unfractionated Heparin; Drug: Gestational Age-Based Dose of Unfractionated Heparin

• Registration Number: NCT04635839
• Lead Sponsor: University of California, Los Angeles

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.

Study Timeline

• Study First Submitted: 2020-11-09
• Study First Submitted QC: 2020-11-13
• Study First Posted: 2020-11-19
• Study Start: 2020-12-15
• Primary Completion: 2022-03-31
• Study Completion: 2022-05-01
• Results First Submitted: 2023-02-07
• Status Verified: 2023-04
• Results First Submitted QC: 2023-04-26
• Last Update Submitted: 2023-04-26
• Results First Posted: 2023-04-28
• Last Update Posted: 2023-04-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 46

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

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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.

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Standard Dosing	Standard Dose of Unfractionated Heparin	Standard dose of unfractionated heparin
Gestational Age-Based Dosing	Gestational Age-Based Dose of Unfractionated Heparin	Dose of unfractionated heparin based on trimester of pregnancy

Primary Outcome Measures

Name	Time	Method
Number of Participants With Elevated Serum Activated Partial Thromboplastin Time Above the Normal Range (> 36.2 Seconds).	Collected 6 hours after unfractionated heparin dose until patient was taken of unfractionated heparin, an average of 1 week	Surrogate marker for whether or not the patient would be eligible for neuraxial anesthesia based on guidelines for neuraxial anesthesia in pregnant women receiving VTE prophylaxis

Secondary Outcome Measures

Name	Time	Method
Number of Participants Diagnosed With Venous Thromboembolism (Pulmonary Embolism and/or Deep Venous Thromboembolism)	Assessed throughout hospitalization, an average length of 8 days, until 6 weeks after delivery
Number of Participants That Received a Blood Transfusion	From time of delivery until 6 weeks after delivery
Maximum Activated Partial Thromboplastin Clotting Time Levels Measured	Collected 6 hours after unfractionated heparin dose until patient was taken of unfractionated heparin, an average of 1 week
Number of Participants Who Did Not Receive or Had a Delay of Neuraxial Anesthesia Due to Unfractionated Heparin	Assessed at time of delivery
Estimated Blood Loss From Delivery	Assessed at time of delivery
Number of Participants That Had a Delay in Timing of Delivery Due to Unfractionated Heparin	Assessed at time of delivery
Number of Participants That Received General Anesthesia	Assessed at time of delivery
Maximum Anti-Factor Xa Level Measured	Collected 6 hours after unfractionated heparin dose until patient was taken of unfractionated heparin, an average of 1 week
Mode of Delivery	Assessed at time of delivery

Trial Locations

Locations (1)

UCLA Medical Center; 🇺🇸 Los Angeles, California, United States