This document provides guidelines for thromboprophylaxis during pregnancy, labor, and after vaginal delivery. It outlines various risk factors for venous thromboembolism (VTE) including pre-existing conditions like previous DVT or thrombophilia, as well as transient risks from procedures, immobilization, or medical complications. It recommends individual assessment and management based on risk factor profile, including consideration of antenatal low molecular weight heparin for high risk groups like those with previous VTE or inherited thrombophilia. Postpartum prophylaxis for at least 6 weeks is also advised for many groups based on their VTE risk.

1. THROMBOPROPHYLAXIS DURING PREGNANCY, LABOUR ANDAFTER VAGINAL DELIVERY Dr.V.Ravimohan

2. Sources 1.Royal College Of Obstetrician & Gynaecologist guidelines 2.Medical disorders in Obstetrics & Gynaecology Edited by Michael de Swiet

3. Pre conceptual antenatal risk assessment Pre pregnancy counselling -women at high risk of VTE, including those with previous confirmed VTE, should be offered with a prospective management plan. Pre pregnancy & early pregnancy -an individual assessment of thrombotic risk should be undertaken. Assessment should be repeated if the woman is admitted to hospital or develops other intercurrent problems.

4. Risk factors 2 types-Pre-existing/ New onset or transient

5. Pre-existing Previous DVT Thrombophilia Congenital antithrombin deficiency protein C deficiency protein S deficiency Factor V Leiden prothrombin gene variant Acquired Antiphospolipid

6. Pre-existing Age over 35 years Obesity (BMI > 30 kg/m2) either pre-pregnancy or in early pregnancy Parity > 4 Gross varicose veins Paraplegia Sickle cell disease Inflammatory disorders e.g. inflammatory bowel disease Some medical disorders, e.g. nephrotic syndrome, certain cardiac diseases Myeloproliferative disorders, e.g. essential thrombocythaemia, polycythaemiavera

7. New onset or transient Surgical procedure in pregnancy or puerperium, e.g. evacuation of retained products of conception, postpartum sterilisation Midcavity instrumental delivery Immobility after delivery Pre-eclampsia Hyperemesis Dehydration Excessive blood loss Ovarian hyperstimulation syndrome Severe infection, e.g. Pyelonephritis Immobility (> 4 days bed rest) Long-haul travel Prolonged labour

8. Investigation of women with previous VTE Recognition: good history and received prolonged (6–12 weeks) therapeutic anticoagulation. Investigation: for congenital/acquired ideally pre pregnancy

9. 5 groups of women a previous VTE and no thrombophilia a previous VTE who have inherited thrombophilia inherited thrombophilia without previous VTE acquired thrombophilia (antiphospholipid syndrome) Women without previous VTE or thrombophilia

10. a previous VTE and no thrombophilia antenatal thromboprophylaxis-controversial Indicated if more than one previous episode of VTE a family history of VTE in a first degree relative Consider if Unprovoked DVT Oestrogen related Associated risks ex: high BMI an unusual site (such as the axillary vein) reasonable not to use antenatal thromboprophylaxis If DVT was associated with temporary risk factor Post natal-low molecular weight heparin (LMWH) for six weeks after

11. Women with a previous VTE who have inherited thrombophilia Thromboprophylaxis with LMWH antenatally and for at least six weeks postpartum. higher doses of LMWH may be needed women with symptomatic thrombophilia specific thrombophilias,particularly AT deficiency Seek expert haematological advice

12. Antenatal prophylactic and therapeutic doses of low-molecular-weight heparin

13. Women with inherited thrombophilia without previous VTE Antenatal prophylaxis is not always necessary. Consider if Antithrombin deficiency combined defects homozygosity for defects Other risk factors Postnatal-LMWH or warfarin for six weeks

14. Women with acquired thrombophilia (antiphospholipid syndrome) Antiphospholipid syndrome (APS) Definition: presence of lupus anticoagulant or anticardiolipin antibodies of medium–high titre on two occasions eight weeks apart found in association with a history of thrombosis (arterial or venous) or adverse pregnancy outcome three or more unexplained miscarriages before ten weeks of gestation a fetal death after ten weeks of gestation a premature {less than 35 weeks} birth due to severe pre-eclampsia or intrauterine growth restriction)

15. APS

16. Women without previous VTE or thrombophilia women with three or more current or persisting risk factors should be considered for prophylactic LMWH antenatally at least three to five days postpartum. two current or persisting risk factors should be considered for prophylactic LMWH for three to five days after vaginal delivery. Clinical judgement is required with regard to the weighting of the above risk factors. an extremely obese woman admitted to the antenatal ward may be sufficient to justify antenatal thromboprophylaxis

17. Women without previous VTE or thrombophilia important independent risk factors for postpartum VTE even after vaginal delivery Age over 35 years and BMI greater than 30/body weight greater than 90 kg The combination of either of these risk factors with any other risk factor for VTE (such as pre-eclampsia or immobility) or the presence of two other persisting risk factors should lead the clinician to consider the use of LMWH for three to five days postpartum.

18. Thrombophilia Activated protein C inhibits Factors V & VIII Levels of functional and immunological protein C doesn’t change in pregnancy Protein S is a cofactor for protein C Free protein S drop by 20% at the end of third trimester Thrombosis in Antithrombin deficiency should be treated with heparin & Antithrombin concentrate.

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