Reducing the Risk: TE during Pregnancy & Puerperium, Flashcards
1
Q
Prepregnancy and antenatal risk assessment
What are the risk factors for venous thromboembolism (VTE) in pregnancy and the puerperium and
what is the magnitude of risk for these factors?
A
- All women documented assessment of risk factors for VTE in 1 - early pregnancy or 2 - prepregnancy. 3 - repeated A - if admitted for any reason or B - develops other intercurrent problems. C - intrapartum or D - immediately postpartum.
- with four or more current risk factors shown in (other than previous VTE or thrombophilia) for prophylactic LMWH throughout antenatal & 6 wks postnatally but postnatal risk reassessment should be made.
- with three current risk factors (other than previous VTE or thrombophilia) for prophylactic LMWH from 28 wks & usually require prophylactic LMWH for 6 weeks postnatally but postnatal risk reassessment be made.
- with two current risk factors shown in (other than previous VTE or thrombophilia) consider prophylactic LMWH for at least 10 days postpartum.
- admitted to hospital pregnant (including to gynaecology ward with hyperemesis gravidarum or ovarian hyperstimulation syndrome) usually offer thromboprophylaxis
- unless specific contraindication such as risk of labour or active bleeding.
- risk of VTE discuss with women & reasons for individual recommendations explained.
2
Q
How should women with single previous VTE be managed in pregnancy?
A
- offer prepregnancy counselling & prospective MX plan for thromboprophylaxis in pregnancy.
- become pregnant before receiving such counselling refer at earliest opportunity in pregnancy to clinician with expertise in thrombosis in pregnancy.
- previous VTE (except single previous VTE related to major surgery and no other risk factors) offer thromboprophylaxis with LMWH throughout antenatal period.
- previous VTE careful history documented. Where objective documentation is not available, the previous diagnosis of VTE can be assumed in cases where the woman gives a good history and received prolonged (greater than 6 weeks) therapeutic anticoagulation.
3
Q
Heritable thrombophilia
A
- previous VTE associated with antithrombin deficiency (often be on long-term oral anticoagulation) offer thromboprophylaxis, higher dose LMWH (either 50%, 75% or full treatment dose) antenatally and for 6 weeks postpartum or until returned to oral anticoagulant therapy after delivery.
- MX undertaken in collaboration with a haematologist with expertise in thrombosis in pregnancy & consideration given to antenatal anti-Xa monitoring & potential for antithrombin replacement at initiation of labour or prior to caesarean section.
- If anti-Xa levels are measured, test not use exogenous antithrombin should be used and 4-hour peak levels of 0.5–1.0 iu/ml aimed for.
- Other heritable thrombophilic defect lower risk & can be managed with standard doses of thromboprophylaxis.
4
Q
Acquired thrombophilia – see also section 4.4
A
- VTE associated with APS (who will often be on longterm oral anticoagulation) should be offered thromboprophylaxis with higher dose LMWH (either 50%, 75% or full treatment dose) antenatally and for 6 weeks postpartum or until returned to oral anticoagulant therapy after delivery.
- APS and prior VTE or arterial thromboses should be managed in collaboration with haematologist and/or rheumatologist with expertise in this area.
5
Q
What extra advice is needed for women with previous recurrent VTE?
A
- doses advice of LMWH in pregnancy from clinician with expertise in haemostasis and pregnancy.
- Some with previous recurrent VTE require higher doses of LMWH.
- on long-term warfarin or other oral anticoagulants counsell risks of these to fetus & advised to stop their oral anticoagulant therapy & change to LMWH as soon as pregnancy is confirmed, ideally within 2 weeks of missed period and before 6th wk.
- Women not on warfarin or other oral anticoagulants advise start LMWH as soon as positive pregnancy test.
6
Q
How should women with previous VTE be stratified to determine management in pregnancy?
A
- VTE associated with either antithrombin deficiency or APS or with recurrent VTE (who will often be on long-term oral anticoagulation) offer thromboprophylaxis with higher dose LMWH (either 50%, 75% or full treatment dose) antenatally and for 6 weeks postpartum or until returned to oral anticoagulant therapy after delivery.
- specialist management by experts in haemostasis and pregnancy.
- original VTE was unprovoked/idiopathic or related to estrogen (estrogen-containing contraception/pregnancy) or related to a transient risk factor other than major surgery or who have other risk factors should be offered thromboprophylaxis with LMWH throughout the antenatal period.
- original VTE was provoked by major surgery from which they have recovered and who have no other risk factors, thromboprophylaxis with LMWH can be withheld antenatally until 28 weeks provided no additional risk factors (in which case offer LMWH).
- They require close surveillance for the development of other risk factors.
7
Q
Which women with prior VTE require thrombophilia testing?
A
- Prior to testing for thrombophilia, women should be counselled regarding the implications for themselves and family members of a positive or negative result.
- results should be interpreted by clinicians with specific expertise in area.
- family history of VTE and either antithrombin deficiency or if specific thrombophilia has not been detected test for antithrombin deficiency.
- an unprovoked VTE test for presence of APL antibodies.
8
Q
How should women with asymptomatic thrombophilia be treated?
A
- stratified according to level of risk associated with their thrombophilia & presence or absence of a family history or other risk factors.
- with asymptomatic antithrombin, protein C or S deficiency or with > one thrombophilic defect (including homozygous factor V Leiden, homozygous prothrombin gene mutation and compound heterozygotes) refer to local expert & antenatal prophylaxis considered. recommend for six weeks’ postnatal prophylaxis even
in absence of additional risk factors. - Heterozygosity for factor V Leiden or prothrombin gene mutation or antiphospholipid antibodies considered as risk factors for thrombosis in asymptomatic women.
- In presence of three other risk factors such women consider for antenatal thromboprophylaxis,
- if two other risk factors thromboprophylaxis consider from 28 weeks & if one other risk factor postnatal thromboprophylaxis for 10 days consider.
- no personal history or risk factors for VTE but who have a family history of an unprovoked or estrogen-provoked VTE in a first-degree relative when aged < 50 years consider for thrombophilia testing. more informative if relative has a known thrombophilia.
9
Q
How should women with antiphospholipid antibodies be treated?
A
- Persistent antiphospholipid antibodies (lupus anticoagulant and/or anticardiolipin and/or β2-glycoprotein 1 antibodies) without previous VTE consider as risk factor for thrombosis such that if she has other risk factors, maybe considered for antenatal or postnatal thromboprophylaxis as above.
10
Q
When should thromboprophylaxis be started?
A
- Antenatal thromboprophylaxis for previous VTE begin as early in pregnancy as practical.
- without previous VTE & without particular first trimester risk factors or admission to hospital, but with four other risk factors, consider for antenatal prophylaxis throughout pregnancy.
- without previous VTE & without particular Ist trimester risk factors or admission to hospital, but 3 other risk factors, can start antenatal prophylaxis at 28 wks.
11
Q
What are the first trimester risk factors for VTE and how should they be managed?
A
- admitted with hyperemesis consider for thromboprophylaxis with LMWH & discontinue thromboprophylaxis when hyperemesis resolves.
- with OHSS, consider thromboprophylaxis with LMWH in first trimester.
- IVF pregnancy and three other risk factors consider for thromboprophylaxis with LMWH starting in first trimester.
12
Q
When should thromboprophylaxis be interrupted for delivery?
A
- receiving antenatal LMWH: advise if any vaginal bleeding or once labour begins, not inject any further LMWH. reassessed on admission to hospital and further doses should be prescribed by medical staff.
- Regional techniques avoided if possible until at least 12 hours after previous prophylactic dose of LMWH.
- LMWH not given for 4 hours after spinal anaesthesia or after epidural catheter removed and catheter should not be removed within 12 hours of most recent injection.
- woman presents while on a therapeutic regimen of LMWH, regional techniques avoided if possible for at least 24 hours after last dose of LMWH.
- receiving antenatal LMWH having elective CS receive
thromboprophylactic dose of LMWH on day prior to delivery and, on day of delivery, any morning dose omitted & operation performed that morning. - first thromboprophylactic dose of LMWH given ASAP after delivery provided no PPH & regional analgesia not been used.
- high risk of haemorrhage with risk factors including major APH, coagulopathy, progressive wound haematoma, suspected intra-abdominal bleeding and
PPH may be managed with anti-embolism stockings (AES), foot impulse devices or intermittent pneumatic compression devices. - Unfractionated heparin (UFT) may also be considered.
If develops haemorrhagic problem while on LMWH treatment should be stopped & expert haematological advice sought. - Thromboprophylaxis should be started or reinstituted as soon as immediate risk of haemorrhage reduced
13
Q
What are the risk factors for VTE after delivery?
A
- class 3 obesity (BMI > or = 40 kg/m2 ) consider for prophylactic LMWH in doses appropriate for their weight for 10 days after delivery.
- with two or more persisting risk factors should be considered for LMWH in prophylactic doses appropriate for their weight for 10 days after delivery.
14
Q
Which women with previous VTE need postpartum thromboprophylaxis?
A
- previous history of confirmed VTE offer thromboprophylaxis with LMWH or warfarin for at least 6 wks postpartum regardless of mode of delivery.
15
Q
Asymptomatic thrombophilia
Which women with thrombophilia without previous VTE need postpartum thromboprophylaxis?
A
- thrombophilia without previous VTE stratified according to both level of risk associated with their thrombophilia & presence or absence of family history or other risk factors.
- family history of VTE and an identified thrombophilia consider for 6 wks’ postnatal thromboprophylaxis
