Thromboembolic disease In obstetrics and Gynaecology

Aboubakr Elnashar

UK: Pulmonary embolism (PE) is the most common

cause of maternal mortality (16.5%)

(TED, PIH, Haemorrhage).

Egypt: PE represents 6% of maternal mortality

(Haemorrhage, PIH, TED).

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Pregnancy and childbirth are associated

with 10 fold increased risk of TED

{ Stasis.

Increased coagulation factors.

Trauma during delivery}.

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All women should undergo an assessment of risk factors for VTE in

early pregnancy or before pregnancy &

should be repeated if the woman is admitted to hospital or develops other intercurrent problems.

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At booking

Age over 35 years.

Obesity :BMI>30.

Past history of

DVT/PE.

Family history of TED.

Anti-phospholipid

syndrome. During pregnancy

•Dehydration: HG,GE,

diarrhoea.

•Prolonged bed rest.

•Immobilisation.

•Pre-eclampsia

•Gross varicose veins.

At & after delivery

•Prolonged active labour >12

hours.

•Emergency C/S.

•Caesarean hysterectomy.

•Prolonged bed rest

•Immobilisation.

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Women with a previous VTE should have:

1. Careful history documented and

2. Undergo screening for both inherited and acquired thrombophilia,

ideally before pregnancy.

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A) During pregnancy.

B) Following C/S.

C) Following vaginal deliveries.

D) During travelling by air.

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A) Thrombo-prophylaxis during

pregnancy

Women with past history of TED during a previous pregnancy or puerperium should receive heparin/LMWH.

With no added risk factors --- heparin/LMWH before the time of the previous TED till 6 weeks postpartum.

With multiple episodes of TED heparin/LMWH throughout pregnancy till 6 weeks postpartum (shift to oral after delivery).

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B) Thrombo-prophylaxis following C/S (RCOG guidelines).

1) Low risk group:

Elective C/S

Uncomplicated pregnancy.

No added risk factors.

Early mobilisation and hydration.

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2) Moderate risk group

Patients with any one of:

Age >35 years

Obesity >80Kg.

Parity 4 or more.

Active labour >12 hs

Gross varicose veins.

Current infection(>4days).

Pre-eclampsia.

Immobility

Major current illness: heart or lung disease, cancer, IBD, NS.

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3) High risk group

3 or more moderate risk factors.

Major surgery: caesarean hysterectomy.

Past or family history of DVT/PE.

Thrombophilia, immobile patients .

Antiphospholipid syndrome.

Heparin/LMWH + leg stockings for 5 days.

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C) Thrombo-prophylaxis following vaginal delivery

1) Low risk: uncomplicated delivery

Early mobilisation & avoid dehydration.

2) Moderate risk: 2 risk factors.

Heparin/LMWH sc daily till discharge.

3) High risk: 4 or more risk factors.

Heparin/LMWH sc+ Elastic stokings till discharge

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Timing

Antenatal thromboprophylaxis:

as early in pregnancy as practical.

Postpartum prophylaxis:

as soon as possible after delivery provided that there

is no postpartum haemorrhage.

Postpartum haemorrhage

should be fitted with thromboembolic deterrent

stockings.

B

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Regional analgesia:

LMWH should be withheld until four hours after

insertion or removal of the epidural catheter (or six

hours if either insertion or removal were traumatic).

The first postpartum dose can be given after insertion but before removal of the epidural catheter.

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Duration of postpartum thromboprophylaxis

High risk: 6 w

Lower risk: 3-5 days

{The prothrombotic changes of pregnancy do not

revert completely to normal until several weeks

after delivery}

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D) Thrombo-prophylaxis during travelling by air

Risk factor Short haul flight

<4 hours

Long haul flight

>4hours

No added

risk

Move around cabin

Avoid dehydration

Minimise coffee

The same+

Well fitted below knee

elastic stockings.

Added risk

factors

The same +

Well fitted below knee

elastic stockings.

LMWH pre-flight and

the day after

Or 75 mg Aspirin 3 days

before & on day of travel.

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Dose

• Unfractionated heparin: 5000-10000 u /12 h.

• LMWH:

Dalteparin (Fragmin): 2500-5000 u /24 h.

Enoxoparin (Clexane): 20-40 u /24 h.

Tinzaparin (Innohip) : 3500-4500 u /24 h.

• Oral anticoagulants are indicated in patients with

cardiac valve replacement only.

Heparin

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Monitoring

Heparin: APTT.

LMWH by Xa (not available in Egypt).

(Monitoring is not required for short term treatment).

Platelet count every 2 weeks.

Oral anticoagulants by INR (International

normalization Ratio), usually weekly.

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Contraindications to heparins

Haemorrhagic disorders: haemophilia.

Thrombocytopenia.

Peptic ulcer.

Recent cerebral hge.

Severe hypertension.

Severe liver disease.

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Side effects of prolonged heparin therapy

Haemorrhage.

Skin necrosis at injection sites.

Thrombocytopenia.

Osteoporosis.

Hypersensitivity reactions.

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Systematic reviews and retrospective studies have concluded that LMWH is a safe alternative to unfractionated heparin as an anticoagulant during pregnancy and from a safety perspective LMWH is preferred.

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Low-dose aspirin

75 mg daily

Safe in pregnancy, although its use for thromboprophylaxis in this setting has never been assessed by RCT.

Meta-analysis of trials in surgical and medical patients shows a significant reduction in DVT and PE with antiplatelet prophylaxis.

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May be appropriate in situations where the risk of

VTE is increased but is not deemed high enough to

warrant the use of antenatal LMWH

e.g.women with previous provoked VTE without

thrombophilia.

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Warfarin

During pregnancy, especially between

6 and 12 weeks: should be avoided if

possible, because

1. 5% risk of teratogenesis

2. increases the risk of miscarriage,

3. fetal and maternal haemorrhage,

4. neurological problems in the baby and

stillbirth.

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After delivery and for breastfeeding; safe, although it requires :

1. Close monitoring,

2. Frequent visits to an anticoagulant clinic

Warfarin carries an increased risk of:

1. Postpartum haemorrhage and

2. Perineal haematoma compared with LMWH.

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It is not appropriate for women requiring only three to five days of postpartum prophylaxis.

If the woman chooses to commence warfarin postpartum, this can usually be initiated on the second or third postnatal day.

The dosage regimens are the same as for women converting to warfarin postpartum following an acute VTE in pregnancy.

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Graduated elastic compression stockings

There are no trials to support such practice but

the British Society for Hematology guidelines

give a grade C recommendation (evidence

level IV) that:

All women with previous VTE or a thrombophilia

should be encouraged to wear class-II

graduated elastic compression below knee

stockings throughout their pregnancy and for

6–12 weeks after delivery.

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Class-I thromboelastic stockings are appropriate for hospital inpatients at increased risk of VTE and may be combined with LMWH.

Their use is also recommended for pregnant women traveling by air.

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The pregnancy-associated prothrombotic changes in

the coagulation system are maximal immediately

following delivery.

Therefore, it is desirable to continue LMWH during

labour or delivery in women receiving antenatal

thromboprophylaxis with LMWH.

Care during labour and delivery for

women on thromboprophylaxis

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For women receiving high prophylactic or

therapeutic doses of LMWH:

the dose of heparin should be

withheld if the woman goes into labour or

reduced to its thromboprophylactic dose on the

day before induction of labour or elective CS and

continued in this dose during labour.

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Regional anaesthesia can be sited only after discussion with a senior anaesthetist, & with the woman before labour or CS.

To minimize the risk of epidural hematoma, regional techniques should not be used until at least 12 hours after the previous prophylactic dose of LMWH.

When a woman presents while on a therapeutic regimen of LMWH, regional techniques should not be employed for at least 24 hours after the last dose of LMWH.

LMWH should not be given for at least 4 hrs after the epidural catheter has been inserted or removed and the cannula should not be removed within 10–12 hrs of the most recent injection.

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DVT is suspected by:

Acute leg pain,

Swelling, redness &

tenderness.

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PE is suspected by

Acute chest pain,

shortness of breath.

Haemoptysis,

Hypotension and

Cyanosis occur in massive PE.

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ECG, Oxygen saturation& CXR are

not specific.

The clinical diagnosis is very

difficult, but

If suspected, start treatment till

objective tests are available.

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Objective testing for TED

DVT: Duplex ultrasound scan.

PE: ventilation/perfusion scan.

Chest X-ray and X-ray venography carry a very

small risk of radiation exposure to the fetus and should be used when indicated.

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Aboubakr Elnashar

Pulmonary angiography & VP scan

Multiple intravascular filling

defects in the right pulmonary

artery on angiogram.

There are several bilateral segmental

perfusion defects without matched

ventilation defects in the same

territories (mismatch). Aboubakr Elnashar

Management of acute episodes of VTE

1. Therapeutic doses of Heparins for at least 5 days.

(Consult other specialities).

IV loading dose followed by continuous IV infusion or intermittent SC injection.

5000-10000 u loading dose followed by

15-25 u/kg/h iv infusion or

15000 u sc/12 h.

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Monitoring (consult other specialities)

Daily monitoring by APTT, adjust dose

accordingly.

Continue tt throughout pregnancy at a

maintenance dose.

Continue till 6 w postpartum (shift to oral

after delivery).

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2. LMWH (therapeutic doses).

Enoxaparin (clexane) 20, 40, 60, 80,100 120, 150 mg/syringe.

Dose: 1-1.5 mg/kg(150 u/kg) sc every 24 h.

Tinzaparin (Innohep) 2500, 3500, 4500, 20000 u/syringe.

Dose: 175 u/kg sc every 24 h.

Dalteparin (Fragmin) 2500, 5000, 10000, 12500, 15000, 18000 u/syringe.

Dose: 200 u/kg sc (maximally 18000 u/day).

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Response to treatment

Immediate improvement in DVT/PE.

Patients with persistent hypotension,

cyanosis carry a bad prognosis.

Thrombolytic therapy by streptokinase.

Surgical treatment.

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Risk assessment based upon:

A) Type of surgery.

B) Risk factor in the patient.

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A) Type of Surgery

Low risk surgery:

Minor operations (<30 minutes).

Moderate risk surgery:

>30 minutes.

High risk surgery

All cancer/extended pelvic surgery.

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B) Risk factor in the patient

The same risk factors mentioned under obstetrics.

Age>40 years.

BMI>30.

Immobility.

Thrombophilia.

Previous DVT/PE.

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Thrombo-prophylaxis

1. Minor surgery & no risk factors

Early mobilization &

avoid dehydration.

2. Moderate surgery and no risk factors

Low dose prophylaxis (20 mg clexane) prior to surgery and daily till discharge.

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3. Prolonged surgery and/or high risk factors High dose prophylaxis (40-80 mg clexane) prior

to surgery & daily till discharge. Compression stockings during

surgery/comfortable positions. Elastic stockings following surgery. Early mobilization and hydration.

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Management of patients on Anticoagulants undergoing surgery

Patients on oral anticoagulants

Admit to hospital 3-4 days prior to surgery.

Stop oral anti-coagulant and start

heparin/LMWH on admission.

Surgery when INR between 1-2.

Start oral anticoagulant after oral feeding +

heparin/LMWH for few days.

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Patients on heparin/LMWH

Stop LMWH on the night prior to surgery

or morning dose of heparin.

Start few hours after surgery.

Start oral +heparin for few days.

Continue on oral when INR>2.

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Antidotes

Protamin zinc for heparin.

Vit K for oral anticoagulants.

No effective antidote for LMWH.

(may be fresh blood transfusion).

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Thromboprophylaxis in OHSS

Women with multiple risk factors for VTE and at risk of OHSS undergoing ovulation induction may also be considered for thromboprophylaxis.

Women with OHSS require thromboprophylaxis for at least the period of inpatient stay.

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