Thromboprophylaxis in pregnant patient-specific risks

Background: Pregnancy and the puerperium are well-established risk factors for venous thromboembolism. Prothrombotic changes start after conception and normal coagulation returns eight weeks after the labour The risk of DVT is approximately twice as high after caesarean delively than vaginal birth. Specific risks: Inherited or acquired thrombophilias increase thromboembolic risk and influence the approach to thromboprophylaxis. Additional factors that increase thrombotic risk include immobilisation, such as bed rest for pregnancy complications, surgery including caesarean section, ovarian hyperstimulation during gonadotropin use for in vitro fertilisation, trauma and malignancy. The preferred agents for thromboprophylaxis in pregnancy are heparin compounds; these agents do not cross the placenta and therefore appears safe for the fetus. Because of the theoretical risk of epidural spinal haemorrhage in women receiving heparin that undergo epidural or spinal anaesthesia many anaesthesiologist will not perform neuraxial regional anaesthesia in women who have recently received heparin. Anaesthesia guidelines advise waiting to insert the needle at least 10 to 12 hours after the last prophylactic dose of LMWH, and at least 24 hours after the last therapeutic dose. Conclusion: Despite the increased risk of thrombosis in pregnancy, anticoagulants are not routinely indicated, because the risks usually outweigh the benefits. The exception is women on life-long anticoagulation or women with history of thrombosis or thrombophylia. Heparin therapy must be interrupted temporarily during the immediate peripartum interval to minimise the risk of haemorrhage and to allow for the option of regional anaesthesia.