24

Hereford Hospitals NHS Trust Policy Reference 25MaternityThromboprophylaxis in pregnancy, following vaginal delivery

and caesarean section

Thromboprophylaxis in pregnancy, following vaginal delivery and caesarean sectionPolicy Details: Author job title: Mr D Mowbray, Consultant Obstetrician

Dr S Willoughby, Consultant Haematologist

Dept/Working Group(s):

Maternity

Current review changes:OptionsSubstantially reviewed and re-written/revised

Ratifying Body: Labour Ward Forum

Date ratified: 16/05/07

Date operational: 11/07/07

Date to be reviewed: April 2010

PFI involvement: project liaison completed accordingly (Yes/No) No

Refers to the following Trust policies:

Review History: First Operational: October 2003

Previously Reviewed: January 2007April2007

Updated yes/no: YesYes

Pulmonary thromboembolism (PTE) remains a major cause of maternal death in the UK.

The incidence of DVT is shown in the table below:

Maternal AgeAntenatalPostnatal

< 350.615 per 10000.304 per 1000

> 351.216 per 10000.720 per 1000

Thrombophilic abnormalities affect 15% of the population. Risk factors may act synergistically. 1 Low molecular weight heparin (LMWH) is the anticoagulant of choice in pregnancy as it does not cross the placenta.

Monitoring is required for therapeutic doses and a twice daily dosing regime should be considered in view of the altered pharmacokinetics in pregnancy.

Skin rashes are occasionally seen with LMWHs and are seen more commonly in pregnancy.

The LMWH used in Hereford County Hospital is tinzaparin: Therapeutic dose = Tinzaparin 175u/Kg/day(or 90u/kg 12hourly) Prophylactic dose = Tinzaparin 3500u/day if90kg Note all weights are booking/early pregnancy weightsMonitoring of LMWH It is only necessary to monitor levels for women on therapeutic doses of LMWH It can only be done by using an anti-X assay as the APTT is not affected by LMWH It is arranged by liaison with the Haematology laboratory - ext 5710

Anti-Xa levels should be checked every 4 weeks during the 1st and 2nd trimesters and every 2 weeks in the 3rd trimester and LMWH doses altered accordingly.

Levels should be taken exactly 4 hours post sc injection to get an accurate peak level.It is important to monitor platelet counts of ALL patients on heparin therapya) before startingb) after seven days on heparin.

Target range for Anti-Xa level:Therapeutic heparin

0.3 - 0.7 iu/ml

Prophylaxis for patients with thrombophilia or previous history of venous thromboembolism (VTE)1. Single VTE associated with a clear precipitating cause which is now resolved OR

Asymptomatic thrombophilia (without an episode of VTE) of types

a) heterozygous factor V Leiden (FVL)

b) heterozygous protein C/S deficiency

c) heterozygous prothrombin (PT) mutationTreatment

6 weeks postnatal prophylactic dose LMWH or warfarin (INR target 2.5) Consider antenatal LMWH if strong +ve family history of VTE2. Single VTE with no precipitating cause, at unusual site, associated with a)a positive family history (1st degree relative) of VTE

b) homozygous FVL/ PT mutation c)recurrent VTE (not on long term warfarin)Treatment Prophylactic dose antenatal LMWH (as soon as practical) + 6 weeks postnatal prophylactic LMWH or Warfarin (INR target 2.5)3. If Antithrombin III (AT III) deficientTreatment

Therapeutic dose LMWH throughout pregnancy, AT III concentrate at delivery and therapeutic dose LMWH or warfarin 6/52 postpartum (INR target 2.5) 4. If on long term warfarin:Treatment

Convert to LMWH prior to conception if possible to avoid teratogenic effects of warfarin.

Therapeutic does of LMWH throughout pregnancy and convert back to warfarin postpartum.

For combined thrombophilic defects, antiphospholipid syndrome or for any women who do not fit within these guidelines, please discuss on an individual basis with a consultant haematologistRecommendation for delivery

For patients on prophylactic doses of LMWH, delivery can proceed as per normal.

For patients on therapeutic doses of LMWH, it is advisable to reduce to a prophylactic dose on the day of delivery, if this can be planned.For patients on therapeautic LMWH who present unplanned in labour

If last dosage > 6hrs ago site venflon, x-match 4 units blood and manage normally (low risk of haemorrhage)

If last therapeutic dose 35

Obesity, BMI > 30 (or weight >80Kg)

Parity >4

Labour >12hrs

Gross varicose veins

Current Infection

Pre-eclampsia

Immobility prior to surgery >4 days

Major current illness

Emergency caesarean in labour

High Risk

Patient with 3 or more moderate risk factors

Extended pelvic or abdominal surgery, e.g. Caesareanhysterectomy

Patient with a personal or family history of:

DVT

PE

ThrombophiliaAntiphospholipid antibody*Lupus anticoagulant*Paralysis of lower limbs

*these patients should have an individualised prophylaxis programme agreed with a

consultant haematologist in the antenatal periodLength of treatment: Low risk - continued until discharge Moderate and high risk - continue until day 5 or fully mobile whichever is later (i.e. the minimum length of treatment is 5 days) Women in the high risk group only should be discharged with TED stockings, unless otherwise instructed by medical staff Heparin dosage after caesarean section (booking or early pregnancy weight) Low risk

early mobilisation/hydration only

Moderate risk

Tinzaparin 3500iu o.d. 90kgTinzaparin 4500iu 12 hourly The first dose should be prescribed for four hours after surgery

Subsequent doses should be prescribed at 22.00hrs

If the first dose is given before 10am give a second dose of 3500iu at 22.00hrs

If the first dose is to be given after 10am miss out that day's evening dose and continue with subsequent doses the following day at 22.00hrs

Thromboprophylaxis after Vaginal Delivery

Risk factors for venous thromboembolism in pregnancy and the puerperium

Those women who are at low risk (non or one of the above risk factors) require early mobilisation and avoidance of dehydration only

Women with three or more pre-existing risk factors should be considered for and offered antenatal heparin prophylaxis and for five days post partum

Women with two current risk factors (to include pre-existing and new onset/transient factors) should be considered for and offered heparin prophylaxis for five days post-partum

Heparin dosage after vaginal delivery (booking or early pregnancy weight) Tinzaparin 3500iu o.d body weight 90kg

Discharge

Self administration

1. The women should ideally be taught to self administer the heparin and should continue to give the heparin at 22.00hrs

2. It must be ensured that the woman is sent home with sufficient heparin to complete the treatment course

Non-self administration

1. If it is not possible for the woman to self-administer the heparin then a community midwife will need to administer the heparin

2. On the day of discharge administer the heparin after 10.00hrs and BEFORE the woman leaves the ward

3. Subsequent doses should be given between 10.00 and 14.00hrs or at another convenient time (ideally it should be the same time each day)

4. It must be ensured that the woman is sent home with sufficient heparin to complete the treatment course

References

1. Greer I. Treatment of Venous thromboembolism in pregnancy, Reprod Vasc Med 2001; 1(4):114-19

2. Royal College of Obstetricians and Gynaecologists. Report of a Working Party on Prophylaxis against Thromboembolism in Gynaecology and Obstetrics. London: RCOG; 1995

3. Thromboprophylaxis during pregnancy, labour and after vaginal delivery RCOG Guideline No. 37 January 20044. BCSH guideline: Investigation and management of Heritable thrombophilia, I Walker et al, ,BJ Haem 2001,114,512-5285. BCSH guideline: Guidelines on the use and monitoring of heparin, T Baglin et al, 2006 BSH, 133, 19-34

6. Confidential Enquiry into Maternal and Child Health. Why Mothers Die. 2000-2002. CEMACH

New onset or transient

Surgical procedure in pregnancy or puerperium

Hyperemesis

Dehydration

OHSS

Severe infection

Immobility (>4 days bed rest)

Pre-eclampsia

Excessive blood loss

Long-haul travel

Prolonged labour

Mid-cavity instrumental delivery

Immobility after delivery

Pre existing

Thrombophilia*

Age >35yrs

BMI>30 pre-pregnancy/early pregnancy

Parity>4

Gross varicose veins

Paraplegia

Sickle cell disease

Inflammatory disorders

Nephrotic syndrome

Myeloproliferative disorders

*these patients should have an individualised prophylaxis programme agreed with a

consultant haematologist in the antenatal period

Appendix 1

PAGE

Operational Date: 11/07/07Date Approved by LWF: 16/05/07

Review Date: April 2010

Page 9 of 9

_1043150215.bin