Thromboprophylaxis in Pregnancy and the Puerperium Max Brinsmead PhD FRANZCOG June 2015

Background Pulmonary embolism is the leading cause of maternal deaths in developed countries May be prevented by thromboprophylaxis measures However, absolute risk is small (1-2 per 1000 pregnancies) And only 1:100 patients with VTE will die Some risks associated with therapy So screening for treatment is required And recommendations for some populations may not be universally applicable

Who requires thromboprophylaxis? Any patients with any previous VTE Except those that had a previous VTE related to major surgery and have no other risk factors Any patient admitted to hospital with dehydration e.g. associated with hyperemesis or OHSS Any patient with 2 or more risk factors as per following tables

Who is at risk? Known thrombophilia Age >35 Para >3 BMI >30 Smokes IV Drug user Severe varicose veins (above knee, phlebitis or skin changes) Medical condition e.g. active SLE, heart failure, cancer, nephropathy Sickle cell disease Paraplegia Travel >4 hrs Immobilisation >3d IVF Pregnancy

Who is at risk (2)? Dehydration e.g. hyperemesis gravidarum or OHSS Pre eclampsia Twins Caesarean section (CS) Emergency CS Prolonged labour Stillbirth Midcavity assisted delivery PPH requiring transfusion Surgery or fracture in pregnancy or the puerperium Any infection requiring admission to hospital or IV antibiotics FOR 2 OF THE ABOVE GIVE CLEXANE FOR 10 days POSTNATAL FOR 3 OF THE ABOVE CONSIDER ANTENATAL CLEXANE from 28 weeks FOR 4 OF THE ABOVE CONSIDER CLEXANE NOW

High Risk Patients Any patient on long term anticoagualants Patients with antithrombin deficiency Patients with antiphospholipid syndrome Patients with prior arterial thrombosis Then Early consultation with haematologist is desirable Usually require higher dose Clexane (75% or full-dose) Planned delivery with anaesthetic consultation desirable

Max Brinsmead PhD FRANZCOG January 2010

When should treatment be started and stopped? As soon as possible for high risk antenatal patient Therefore risk score at 1st opportunity And again with every admission, then at delivery A role for pre pregnancy counselling Patients with personal or family history may benefit from testing for thrombophilia Must stop if there is PV bleeding or onset of labour All patients requiring antenatal therapy require postnatal therapy asap after delivery Not within 12 hours of spinal anaesthetic or insertion or removal of an epidural catheter Continue for 10 days minimum, and 6w if commenced in the antenatal period

What Drug and What Dose? Clexane is the drug of choice Has no risk of thrombocytopenia or osteoporosis Dose by patient weight Use BD for larger doses Prophylaxis postpartum <50 Kg 20 mg once dily 51 – 69 Kg 30 mg once daily 70 – 90 Kg 40 mg once daily 91 – 130 Kg 30 mg 12 hourly 131 – 170 Kg 40 mg 12 hourly Subtherapeutic doses do not need monitoring Therapeutic dose is 1.0 mg/Kg per day antenatally and 1.5 mg/Kg per day in the puerperium

Who should NOT have Clexane or Heparin? Those within 4 hours of spinal or epidural catheter Allergy to LMWH Patients with active bleeding Patients at risk of bleeding e.g. Placenta previa Thrombocytopenia (Platelet count <75) Known bleeding diathesis e.g. Von Willebrands Severe renal disease (GFR < 30 ml/min) Severe liver disease Uncontrolled Hypertension (>200/120) Haemorrhagic stroke within 4w NB Postnatal Clexane increases the risk of PPH and wound haematoma

Other Measures Early mobilisation and avoid dehydration for all Stockings not proven by RCT to be effective Thigh-length may be impractical and poorly tolerated Even knee-length stockings have a limited role for the ambulant patient Should be used in all patients with at least one risk factor until mobilising normally Make sure that they are fitted correctly Use intermittent calf compression for all pregnant patients undergoing surgery

Warfarin Generally contraindicated in the antenatal patient Except for some patients with mechanical heart valves Patients on Warfarin can be advised to switch to LMW Heparin as soon as they have a positive pregnancy test Can be an alternative for a postnatal patient who requires long term therapy Breast feeding is not contraindicated

See RCOG Greentop Guidelines For more detailed guidelines and the treatment of venous thromboembolism in prgnancy See RCOG Greentop Guidelines www.rcog.org.uk/en/guidelines-research-services/guidelines/gtg37a/

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