Pharmacokinetics of Low Molecular Weight and Unfractionated Heparin in Pregnancy

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00721591
Recruitment Status : Completed
First Posted : July 24, 2008
Last Update Posted : November 1, 2016
University of British Columbia
Information provided by (Responsible Party):
University of Chicago

Brief Summary:
To determine, through pharmacokinetic parameters, the ideal dosing protocol for dalteparin (a low molecular weight heparin) and unfractionated heparin for women desiring pregnancy who have evidence of an acquired (specifically, antiphospholipid syndrome) or inherited thrombophilia.

Condition or disease
Recurrent Pregnancy Loss Fetal Demise Abortion, Habitual Antiphospholipid Antibodies Inherited Thrombophilia

Detailed Description:

This study's specific objectives include:

  1. Evaluating pharmacokinetic (concentration-time) and pharmacodynamic (concentration- effect) parameters for dalteparin and UFH prior to pregnancy, during the 1st, 2nd and 3rd trimesters and postpartum, using revised dosing protocols based on previous study.
  2. Determining therapeutic response to the heparins, i.e. live birth rate and lack of maternal or fetal complications, in relation to drug exposure, based on AUC.
  3. Documenting maternal and fetal complications during pregnancy for dalteparin and UFH, using the revised dosing protocols.

Study Type : Observational
Actual Enrollment : 14 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Pharmacokinetics of Low Molecular Weight and Unfractionated Heparin in Pregnancy
Study Start Date : March 2005
Actual Primary Completion Date : January 2013
Actual Study Completion Date : July 2014

Resource links provided by the National Library of Medicine

Subjects opting for treatment with unfractionated heparin
Subjects opting for treatment with low molecular weight heparin

Primary Outcome Measures :
  1. The best dosing strategy for either unfractionated or low molecular weight heparin will be the one exhibiting the best balance between a modified Akaike information criterion value, residual sum of squares, and coefficient of determination. [ Time Frame: Pre-pregnancy, 1st, 2nd, 3d Trimester and post-partum ]

Biospecimen Retention:   Samples Without DNA
Plasma from subjects to obtain concentrations of heparin will be retained

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Ages Eligible for Study:   18 Years to 44 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
The study population will consist of 15 subjects prescribed dalteparin and 15 subjects prescribed unfractionated heparin, who are identified through the University of Chicago Recurrent Pregnancy Loss Program.

Inclusion Criteria:

  • Two or more consecutive, otherwise unexplained miscarriages under 10 weeks of gestation, or, an otherwise unexplained intrauterine fetal demise of at least 10 weeks of gestation, and,
  • Persistently positive antiphospholipid antibodies, or, presence of Factor V Leiden, or, Prothrombin 20210A, or, antithrombin, protein S, or protein C deficiency, or, hyperhomocysteinemia associated with the methylenetetrahydrofolate reductase (MTHFR) polymorphism.

Exclusion Criteria:

  • Inability or refusal to give written informed consent.
  • Inability or refusal to self-administer heparin throughout pregnancy.
  • Hemoglobin value below 9.5 g/dL
  • Heparin use is contraindicated.
  • Renal disease.
  • Documented history of thrombosis.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00721591

United States, Illinois
The University of Chicago
Chicago, Illinois, United States, 60637
Sponsors and Collaborators
University of Chicago
University of British Columbia
Principal Investigator: Mary D. Stephenson, MD, MSc University of Chicago

Responsible Party: University of Chicago Identifier: NCT00721591     History of Changes
Other Study ID Numbers: 13677B
First Posted: July 24, 2008    Key Record Dates
Last Update Posted: November 1, 2016
Last Verified: October 2016

Keywords provided by University of Chicago:
Recurrent Pregnancy Loss
Habitual abortion
Fetal demise
Antiphospholipid antibodies
Inherited thrombophilia

Additional relevant MeSH terms:
Abortion, Habitual
Fetal Death
Abortion, Spontaneous
Pregnancy Complications
Hematologic Diseases
Pathologic Processes
Calcium heparin
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action