15. Thromboprophylaxis

div class=”ChapterContextInformation”>


© Springer Nature Singapore Pte Ltd. 2020
A. Sharma (ed.)Labour Room Emergencieshttps://doi.org/10.1007/978-981-10-4953-8_15



15. Thromboprophylaxis



Rashmi Bagga1   and Rimpi Singla1


(1)
Department of Obstetrics & Gynaecology, PGIMER, Chandigarh, India

 



 

Rashmi Bagga


15.1 Introduction


Pregnancy and the puerperium are known to increase the risk of deep vein thrombosis (DVT) and venous thromboembolism (VTE) [1–3]. The incidence DVT is highest during the puerperium; hence all postpartum women should be instructed about the signs and symptoms and should be examined carefully for any evidence of VTE. Thromboprophylaxis is offered to reduce the risk of VTE and may be in the form of mechanical methods (compression stockings or pneumatic compression devices) or pharmacologic agents (anti-coagulating agents). Screening for and identification of such women who require thromboprophylaxis early during pregnancy or in the preconceptional period reduce the risk of subsequent DVT and VTE [4]. These are women at high risk of VTE and women with prosthetic heart valves, atrial fibrillation, left ventricular dysfunction, cortical venous thrombosis and foetal loss due to anti-phospholipid syndrome. Some factors which add to the risk of VTE are history of VTE in the past, hospitalization and bed rest, caesarean section (CS) and inherited thrombophilia [3–5]. It is possible that some situations develop during the course of pregnancy and puerperium which require thromboprophylaxis. Caesarean section (CS), especially emergency CS, is associated with a higher risk of VTE [4, 6]. Early ambulation and mechanical thromboprophylaxis are usually sufficient to reduce the risk of VTE following CS, and pharmacologic prophylaxis is required only if there are additional risk factors for VTE. Women already on anticoagulant therapy (e.g. for a prosthetic valve) which is to be continued during pregnancy should be switched from oral anticoagulants to a heparin-based regimen as soon as pregnancy is diagnosed in order to avoid potential teratogenic effects of oral anticoagulants. Change from warfarin to LMWH can be done during attempted conception or can be done once pregnancy is confirmed, as long as this switchover is feasible before 6 weeks of pregnancy.


15.2 Indications for Thromboprophylaxis


Women who require pharmacologic anticoagulation during pregnancy and puerperium include those with prosthetic heart valves, atrial fibrillation, left ventricular dysfunction, foetal loss due to anti-phospholipid syndrome, and cortical venous thrombosis and women at high risk for VTE. Most of these indications are described in separate sections, and in the present chapter, the main focus is on thromboprophylaxis to prevent VTE.


Pregnant women who have had a prior VTE which was related to a high oestrogen state (e.g. prior pregnancy or oestrogen-related VTE) are candidates for pharmacologic thromboprophylaxis because these risk factors may result in recurrent VTE during pregnancy. In contrast, women who had a transient risk factor for prior VTE (like trauma, bed rest, surgery) have less likelihood of a recurrent VTE and require only surveillance, general measures to reduce the risk and mechanical thromboprophylaxis. Duration of thromboprophylaxis in postpartum period is usually 6 weeks and up to 3 months in those at a higher risk. However when thromboprophylaxis is administered during hospitalization due to an acute illness, it is usually continued until the patient is ambulatory. The American College of Chest Physicians [7] and the American College of Obstetricians and Gynecologists [8] guidelines for the indications for thromboprophylaxis during pregnancy and puerperium to reduce the risk of VTE are summarized below [4, 7, 8]:


  1. 1.

    Indications for pharmacologic thromboprophylaxis during the puerperium only are:


    1. (a)

      No thrombophilia with prior one episode of VTE associated with a transient risk factor that is no longer present (surveillance alone and no anticoagulation is acceptable).


       

    2. (b)

      Lower-risk thrombophilia with no previous VTE (heterozygous factor V Leiden (fVL) mutation; protein S or protein C deficiency; prothrombin (PT) G20210A heterozygous) with risks factors like obesity/prolonged immobilization or family history of VTE in first-degree relative before age of 50 years.


       

    3. (c)

      Low-risk thrombophilia with one prior episode of VTE.


       

    4. (d)

      High-risk thrombophilia (antithrombin deficiency, homozygous fVL or prothrombin G20210A homozygous, double heterozygous for prothrombin G20210A and fVL).


       

    5. (e)

      No thrombophilia and prior one episode of VTE related to pregnancy or use of oestrogens.


       

    6. (f)

      No thrombophilia and prior one episode of VTE that is not associated with any risk factor (i.e. idiopathic).


       

    In (c–f), during pregnancy, surveillance alone or prophylactic anticoagulation with low molecular weight heparin/unfractionated heparin (LMWH/UFH) are both acceptable.


     

  2. 2.

    Indications for pharmacologic thromboprophylaxis during pregnancy and puerperium are:


    1. (a)

      High-risk thrombophilia and previous one episode of VTE or family history of VTE in first-degree relative.


       

    2. (b)

      Previous two or more episodes of VTE with or without known thrombophilia and not receiving long-term anticoagulation.


       

    3. (c)

      Previous two or more episodes of VTE with or without known thrombophilia and receiving long-term anticoagulation.


       

    4. (d)

      Hospitalized women at risk for VTE (sepsis, pneumonia, trauma, fracture), prolonged bed rest (>3 days) and having other risk factors (obesity, i.e. BMI > 30 kg/m2; older age, i.e. >35 years; multiparity; critical illness; malignancy; ovarian hyperstimulation).


       

     

15.3 Types of Thromboprophylaxis


General measures to prevent VTE should be advised in all women. These are early ambulation, adequate hydration, active and passive leg movements and frequent left-lateral decubitus position during late pregnancy [9].


  1. 1.

    Mechanical methods are the use of graduated compression stockings and pneumatic compression devices. Graduated compression stockings or anti-embolism stockings (AES) provide graduated compression with a calf pressure of 14–15 mmHg. These are recommended in pregnancy and the puerperium in the following [4, 10]:


    1. (a)

      Women who need pharmacologic thromboprophylaxis but have a contraindication to agents due to high risk of haemorrhage, ongoing haemorrhage or coagulopathy.


       

    2. (b)

      In combination with pharmacologic agents in women who are hospitalized post CS and those who are at high risk of VTE.


      Fitting Precautions for AES


       

    3. (a)

      Measure girth of legs and use correct stocking size.


       

    4. (b)

      Demonstrate how to use AES, and encourage women to wear them throughout day and night during hospital stay until they do not have significantly reduced mobility.


       

    5. (c)

      If oedema or post-operative swelling develops, change size of AES.


       

    6. (d)

      Remove AES daily for hygiene and to check skin condition.


       

    7. (e)

      Discontinue use if there is skin marking or discolouration.


      Contraindications to AES [9]


       

    8. (a)

      Known allergy to AES material.


       

    9. (b)

      Suspected or proven peripheral arterial disease or peripheral arterial bypass grafting.


       

    10. (c)

      Peripheral neuropathy.


       

    11. (d)

      Local condition where AES may cause damage (e.g. dermatitis, gangrene, pressure ulcers).


       

    12. (e)

      Severe leg oedema.


       

    13. (f)

      Unusual leg size or shape or leg deformity preventing correct fit.


      Foot Impulse and Intermittent Pneumatic Compression Devices (IPC)


      All women undergoing CS may have pneumatic compression device placed if they are not receiving anticoagulants [1]. Patient with these devices should be encouraged to use them as much as practically possible. Contraindications to their use are acute DVT or PE and those listed for AES.


       

     

  2. 2.

    Pharmacological methods [11]:


    1. (a)

      Heparins: Low molecular weight heparin (LMWH) and unfractionated heparin (UFH).


       

    2. (b)

      Fondaparinux.


       

    3. (c)

      Direct thrombin inhibitor.


       

    4. (d)

      Vitamin K antagonists.


       

     

(a) Heparins: Heparin depends on antithrombin (AT) for its action and clotting factor inhibition. Heparin does not lyse the existing thrombi. Heparin binds and activates AT and induces conformational change. This accelerates AT binding to and inactivation of XIIa, IXa, XIa, Xa and thrombin [12, 13]. UFH can be used as intravenous infusion or subcutaneous injections [13]. Intravenous administration attains therapeutic concentrations in plasma rapidly that can be monitored and modified. Subcutaneous therapeutic dose is large due to low bioavailability. UFH is the best option for patients requiring high doses of anticoagulation and for patients who are at risk of bleeding (like impending delivery) due to its short half-life and reversal capability. It binds to endothelial cells and macrophages and is depolymerised for clearance initially. The second phase of clearance is renal-mediated and is slower and non-saturable. Hence, with the increased or prolonged use of UFH, there is an increase in intensity and duration of its effect [12, 13]. LMWHs are the anticoagulants of choice for thromboprophylaxis during antenatal and postnatal periods. As compared to UFH, LMWHs have higher bioavailability and longer half-life and cause fewer adverse events [14]. It has dose-independent renal clearance. Hence, UFH is preferred over LMWH in severe renal insufficiency (creatinine clearance <30 mL/min) or fluctuating renal function because LMWH metabolism is exclusively renal.

Contraindications/Cautions




  • Known bleeding disorder (acquired coagulopathy, haemophilia or von Willebrand’s disease).



  • Thrombocytopenia.



  • Severe liver disease (increased prothrombin time or known to have varices).



  • Severe renal disease.



  • Women at increased risk of major haemorrhage (e.g. placenta praevia).



  • Active antepartum or postpartum haemorrhage.



  • Acute haemorrhagic or ischaemic stroke in preceding 4 weeks.



  • Uncontrolled hypertension (blood pressure > 200 mmHg systolic or > 120 mmHg diastolic).

Only gold members can continue reading. Log In or Register to continue

Related posts:

  1. 16. Anaphylaxis
  2. in Pregnancy
  3. 10. Diabetes
  4. Surveillance in Labour

Stay updated, free articles. Join our Telegram channel
Tags:
Mar 28, 2021 | Posted by in OBSTETRICS | Comments Off on 15. Thromboprophylaxis

Full access? Get Clinical Tree
Get Clinical Tree app for offline access