DVT(deep vein thrombossi) & Pulmonary embolism are not uncommon causes of sudden deaths in major surgery.

Venous thromboembolism is globally recognized  a leading cause of maternal mortality. However in   West

Incidence 1 in 1500 deliveries (West) 1 in 1000 (India). This may postpartum or post operative. Postpartum DVT  is 3 times  more than antepartum (3-16 times)

More after cesarean section than normal delivery :-The incidence is approximately in 1 in 1500 deliveries seen in the west and according to an Indian study, antenatal DVT is 0.1%. The risk is lower for Asian and Hispanic women, higher for white and highest for black women. Postpartum DVT has been reported to occur 3 to 5 times more often than antepartum DVT and 3 to 16 times more frequent after cesarean section compared to vaginal delivery.

MMR & DVT:_Venous thromboembolism is leading cause of maternal mortality in western world and accounts for 17% of all maternal deaths.

 Mortality is primarily due to massive pulmonary embolism which commonly occurs from a thrombus embolising from deep veins of lower extremities. Pulmonary embolism can occur in up to 24% of untreated patients of deep vein thrombosis. Thrombosis of ileo-femoral veins is more common than thrombosis of calf vein in pregnancy and has a higher risk of pulmonary embolism. Early diagnosis and treatment in patients with acute venous thromboembolism decreases the mortality rate to <1%. Risk factors associated with increased risk for venous thromboembolism have been identified. Primary prophylaxis decreases the rate of thromboembolic events in high risk patients.

PATHOPHYSIOLOGY

Hemostasis is a physiological process of four major steps occurring in set order.

Step 1: Vasoconstriction

Step 2: Activation and aggregation of platelets

Step 3: Formation of fibrin clot

Step 4: Dissolution of clot by plasmin

Hypercoagulability, venous stasis and vascular damage are components of Virchow's triad, all of which occur in pregnancy.

Various physiological changes occur in pregnancy which predispose to a procoagulant state:

Increase in factors VII, VIII, and IX, X and XII and fibrinogen.

Increase in plasminogen activator inhibitors such as tissue plasminogen activator inhibitor and decrease in the levels of tissue plasminogen activator

What are the risk factors for Deep vein thrombosis?? 1) Antiphospholipid antibody syndrome 2) Operative procedure and 3) CS delivery 4) Parity > 4: 5) Pregnancy induced hypertension 6)Age  > 35 years 7) Obesity 8) Gross varicose veins 9) Previous limb # or limb defects or  even Paraplegia 9) Medical disorders: nephritic syndrome, 10) sickle cell disease 11) Myeloproliferative disorders

12) Hypovolemia – so in obese women one can  continue  the drip for 36 hrs or more 13) , massive blood loss 14)

Hyperemesis, 15) dehydration 16) Nonpreg or even pregàif Long distance travel 17) Prolonged immobilization. 18)

Prolonged labor 19) septic abortion,  peritonitis or severe infection, e.g. pyelonephritis 20 ) Ovarian hyperstimulation syndrome21) Operations for ca Cx /Ca ovary à  Malignancy especially pelvic and abdominal