The STOP CLOT Pilot Study: Study of Low Molecular Weight Heparin in High Risk Cesarean Section

• Status: Completed
• Trial end date: 2006-09-01
• Target enrollment: 0
• Participant gender: Female

Summary

Venous thromboembolism (VTE) remains the most common cause of maternal death in the developed world. VTE includes two conditions, deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT refers to a blood clot that has formed in a deep vein, often in the legs and/or pelvis and PE refers to the passage of these clots into the lungs (which can be fatal). VTE is up to 10 times more common in pregnant women than non-pregnant women of comparable age. More than a third of pregnancy related VTE occur during the 6 weeks after delivery. When compared with vaginal delivery, cesarean delivery further increases the risk of pregnancy associated VTE by three-fold.

A medication called low molecular weight heparin is sometimes prescribed during pregnancy and after delivery to prevent VTE. However, clinical practice varies because there hasn't been adequate research to determine that this medication is safe and effective at preventing VTE during this time. The potential benefits of the medication must also be weighed against its cost and possible side effects.

The researchers are conducting a study that will assess the effectiveness and safety of low molecular weight heparin in women who are at moderate to high risk of VTE after a cesarean section. They will monitor these women to determine if those who received the medication have fewer blood clots. Participants will also be monitored closely for any side effects.

• Phase: Phase 2/Phase 3
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Ottawa Hospital Research Institute
• Collaborator: LEO Pharma
• Treatments: Dalteparin; Heparin; Heparin, Low-Molecular-Weight; Tinzaparin

Criteria

Inclusion Criteria (must meet inclusion criteria 1, 2 and 3):

1. At high risk for thromboembolism (any one of the following):

1. Age > 35 years

2. Obesity (> 80 kg)

3. Para 4

4. Gross varicose veins

5. Current infection

6. Pre-eclampsia

7. Immobility prior to surgery (> 4 days)

8. Major current disease: includes heart or lung disease, cancer, inflammatory bowel disease, and nephrotic syndrome.

9. Emergency cesarean section in labour

10. Extended major pelvic or abdominal surgery (e.g. cesarean hysterectomy)

11. Patients with a family history of VTE

12. History of superficial phlebitis

2. Delivered by cesarean section (emergency or planned)

3. Signed, informed consent

Exclusion Criteria (must not meet any of the following criteria):

1. Greater than 36 hours since delivery

2. Need for anticoagulation, including:

1. Women with a confirmed thrombophilia

2. Women with paralysis of lower limbs

3. Women with personal history of VTE

4. Women with antiphospholipid antibody syndrome (APLA)

5. Women with mechanical heart valves

3. Contraindication to heparin therapy, including:

1. History of heparin induced thrombocytopenia

2. Platelet count of less than 100,000 x 10^6/L

3. Hemoglobin <= 90 g/L or a greater than 30 g/L drop in hemoglobin compared to last antepartum result

4. History of osteoporosis

5. History of steroid use (one week or more)

6. Active bleeding

7. Documented peptic ulcer within 6 weeks

8. Heparin, bisulfite, or fish allergy

9. Severe hypertension (systolic blood pressure [SBP] > 200 and/or diastolic blood pressure [DBP] > 120)

10. Severe hepatic failure (International Normalized Ratio [INR] > 1.8)

11. Women with serum creatinine > 80 and an abnormal 24 hour creatinine clearance.

4. Contraindications to magnetic resonance imaging (MRI), including:

1. Women with electrically, magnetically or mechanically activated implants

2. Women with claustrophobia

5. Women < 18 years of age