Thromboembolic disorders
superficial thrombophlebitisDVT
pulmonary embolism
These risks increase postpartum and with CS.
Pregnancy is a hyper coagulable state –Why?
1. In normal pregnancy there is an increase in clotting factors like VII, VIII IX, X and fibronogen
2. Inhibition of the fibrinolytic system
3. Natural anti coag.like anti thrombin III, Protein C, Protein S are reduced
Incidence and Clinical Significance
VTE (venous thromboembolisim) complicates 1.3/1000 pregnancies
Is the leading cause of maternal mortality in developed countries.
25 % of patients with untreated DVT develop PE, and undiagnosed PE has a mortality rate of 30 %.
Following DVT, 29 to 79 % of women suffer post-thrombotic syndrome, with chronic leg pain, swelling, varicose veins, skin discoloration, & ulceration.
5-15% recurrence risk in the future
Risk Factors for VTE
Pre-existingSpecific to pregnancy
Thrombophilia
Age > than 35 years
obesity > 80 kg
Severe varicose veins
Previous VTE
smoking
malignancy
Multiple gestation
Pre-eclampsia
Grand multiparity
Prolonged bed rest
Sepsis
Cesarean section, especially if emergency
Changes in the coagulation/ fibrinolytic system can be:
Inherited
Acquired
Factor V Leiden mutation
Prothrombin G20210A mutation
Methylene tetrahydrofolate reductase mutation
Antithrombin deficiency
Protein C deficiency
Protein S deficiency
Anti-phospholipid antibody syndrome
(Combination of Lupus anticoag abs & anti cardolipin abs with history of recurrent miscarriage &/or thrombosis).
SLE
Clinical signs and symptoms of DVT
90%of DVTs during pregnancy occur in the left leg
72%of DVTs in pregnancy occur in the iliofemoral vein compared with 9% in the calf veins; the former are more likely to embolize.
Symptoms: unilateral leg pain, swelling &redness.
Signs: > 2cm difference in lower leg circumference ,calf tender to gentle touch, Pain with dorsiflexion of the foot (Homan’s sign) is quite nonspecific
Its mandatory to ask about symptoms of PE
Diagnostic testing of DVT
Compression ultrasonography with Doppler flow studies.(noninvasive technique)
MRI- (2nd line) may be used in patients suspected to have pelvic thrombosis with negative Doppler study.
Venography: is invasive, requiring the inj of contrast medium & the use of X-ray, however it allow excellent visualization of veins above & below the knee, it may cause phlebitis
PULMONARY EMBOLISM
2/3 of PEs occurs postpartum.
The clinical picture varies from mild dyspnea and tachypnea accompanied by chest pain, tachycardia (>90 BPM), & mild pyrexia (>37.5 °C) to dramatic cardiopulmonary collapse.
If PE suspected; ECG, chest X-ray, blood gases performed to exclude other causes, u/s for LL for evidence of DVT.
Ventilation perfusion scan (V/Q) or computed tomography pulmonary angiogram (CTPA): in both the radiation to fetus is below threshold & considered safe
D-dimer (screening test): limited clinical usefulness in preg b/c it can be elevated due to physiological changes in preg
Treatment
Anticoagulant therapy should be started when clinical diagnosis is suspected pending the diagnostic tests. And if the diagnosis is excluded by investigations the treatment can be stopped
In PE : O2. ABCs, hemodynamic support
Treatment of proven VTE during pregnancy is with anticoagulants
The IV unfractionated heparin (UFHP) maintained for 5 to 7 days then shift to SC heparin for 6 months, which is continued throughout pregnancy and 6 wks postpartum with weekly monitoring of aPTT 2-3 times the control.
Low molecular weight heparin (LMWH) e.g.:Dalteparin 90-100 units/kg, enoxaparin 1mg/kg, can be administered sc every 12-24 hours (equivalent in efficacy but more safe than UFHP, safe, easy to administer, & fewer hemorrhagic s.e& now the treatment of choice)
Warfarin given orally & prolong PT (used post-partum, rarely used in preg b/c risk of facial & limb defect in the 1st trim & Intra cranial hemorrhage in the 2nd trim, miscarriage, stillbirth except in women with mechanical heart valve, safe in breast feeding)
Following delivery women choose either to convert to warfarin & followed by INR or remain on LMWH
Graduated elastic stockings should be used for the initial treatment of DVT & worn for 2 years following DVT to prevent post phlebitic syndrome
VTE prophylaxis
LMWH is the drug of choice
Antepartum prophylaxis is indicated in case of: previous DVT/PE, known thrombophilia
When to start or stop prophylaxis depends on the clinical situation, usually continued 6 wks post-partum in high risk group (> 3 risk factor)
Mobilization & avoidance of dehydration in low risk group (<2 risk Factor)
Intermediate risk group : thrombo prophylaxis with LMWH 6 days post-partum
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