Clinical trial NCT00721591: Pharmacokinetics of Low Molecular Weight and Unfractionated Heparin in Pregnancy
Official title: Pharmacokinetics of Low Molecular Weight and Unfractionated Heparin in Pregnancy
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Recurrent Pregnancy Loss
Fetal Demise
Abortion, Habitual
Antiphospholipid Antibodies
Inherited Thrombophilia
Keywords: Recurrent Pregnancy Loss
Habitual abortion
Fetal demise
Antiphospholipid antibodies
Inherited thrombophilia
Lead sponsor: University of Chicago
Sponsor class: OTHER
Collaborators: name: University of British Columbia
First posted: 2008-07-24
Enrollment: 14
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 44
Standard ages: ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
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.

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.

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.

Eligibility criteria: 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.

Primary outcomes:
measure: 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.
timeFrame: Pre-pregnancy, 1st, 2nd, 3d Trimester and post-partum
Secondary outcomes:
Other outcomes:
Locations:
city: Chicago
country: United States
facility: The University of Chicago
state: Illinois
Study officials:
affiliation: University of Chicago
name: Mary D. Stephenson, MD, MSc
role: PRINCIPAL_INVESTIGATOR
References: