Coagulation Profile Surrounding Normal Cesarean Delivery
Condition: Pregnancy
Study type: Observational

Summary: 
      Healthy parturients presenting for scheduled cesarean delivery will have blood drawn and
      measured for microparticles at baseline, immediately after delivery, and at several time
      points thereafter.
    

Detailed description: 
      Protocol: Informed consent will be obtained and documented. Subjects who agree to participate
      will have an intravenous line of at least 16 gauge placed by an anesthesiologist via standard
      sterile technique, and lidocaine will be used for patient comfort during the procedure. The
      intravenous line will contain two stopcocks and will be connected to intravenous fluids as
      ordered by the obstetrician or anesthesiologist for patient care. If for any reason the
      intravenous line cannot be used for blood draws, a second intravenous line will be placed for
      the purpose of drawing blood samples. This line will be placed by an anesthesiologist who
      uses lidocaine and operates under standard sterile conditions. This line will not be
      connected to fluids, but to a device with a short piece of tubing used commonly for this
      purpose (often called a "heplock," although no heparin is used); two stopcocks will be
      attached to the end of this device.

      Blood samples will be drawn through the intravenous line (or the "heplock" when it becomes
      necessary to place one) using the following procedure: a 10 mL sterile syringe will be
      attached to the distal stopcock and 5 mL of blood will be withdrawn (to clear the line of
      intravenous fluids). A second 10 mL sterile syringe will be attached to the proximal stopcock
      and 5 mL blood will be withdrawn for assay (total 10 mL blood withdrawn). The blood withdrawn
      to clear the line will be wasted. Finally, a 5 mL normal saline flush will be administered to
      clear the line of blood.

      Blood will be drawn at baseline (placement of intravenous catheter), immediately after
      delivery of the placenta (within 15 minutes), 1 hour postpartum (within 1 hour and 1 hour 15
      minutes), 4 hours postpartum (within 4 hours and 4 hours 15 minutes), and 24-36 hours
      postpartum (5 samples total per subject). After the last blood draw, the intravenous line
      will be discontinued if clinically indicated.

      Blood will be placed in a standard "yellow top" tube and sent to the University's flow
      cytometry lab where it will be centrifuged and will undergo flow cytometry to measure
      microparticles and staining to identify endothelial-, platelet- versus leukocyte-derived
      microparticles and to determine placental origin. In addition Tissue Factor levels in the
      microparticles will be measured. Also, confirmatory image stream microscopy will be
      performed. Data acquisition will be performed on the ImageStreamX with validation on the
      Gallios Cytometer.

      Demographic data collected will include age, height, weight, American Society of
      Anesthesiologists Physical Status Classification, gravidity, parity, estimated gestational
      age, and co-existing maternal or obstetric conditions. Note will be made of the date and time
      of each blood draw, and date and time of delivery of the baby and the placenta. Estimated
      blood loss will be recorded, as will blood product transfusion.

      Sample size: As this is pilot data, a convenience sample of 10 patients will be studied.

      Statistics: Demographic data will be presented primarily with descriptive statistics.
      Comparisons will be made for each assay result among the various time points (i.e., baseline
      values compared to values at subsequent times). Tests for normality will be performed; mean
      and standard deviation will be reported for normal data and median with interquartile range
      for non-normal data. Assay results at various time points will be compared with a mixed-model
      analysis of variance. A P < 0.05 will be required to reject the null hypothesis.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Pregnant women
      
Biospecimen description: 
      Blood