VTE During Pregnancy and the Puerperium
Description Medicine Treatment Referral/Consultation During Pregnancy O22.2-3/O87.0-1/O87.9/O88.3 DESCRIPTION The risk of VTE is substantially increased in pregnancy and is an important cause of maternal morbidity and mortality. MEDICINE TREATMENT Prophylaxis Risk Assessement A risk assessment should be done in pre/early pregnancy and repeated if the woman is admitted to hospital for any reason,
Referral/Consultation During Pregnancy
O22.2-3/O87.0-1/O87.9/O88.3
DESCRIPTION
The risk of VTE is substantially increased in pregnancy and is an important cause of maternal morbidity and mortality.
MEDICINE TREATMENT
Prophylaxis
Risk Assessement
A risk assessment should be done in pre/early pregnancy and repeated if the woman is admitted to hospital for any reason, during delivery, and immediately post delivery.
The decision to provide VTE prophylaxis will depend on an assessment of the patient’s risk for thromboembolism:
Table 2.6: Indications for VTE prophylaxis and duration of therapy
| Indications | Duration of therapy |
| Previous VTE episode (DVT or pulmonary embolism) |
VTE prophylaxis during pregnancy and for up to 6 weeks post-delivery. LoE:IIIbxl |
| Patient with any ONE of the following high risk factors: - Emergency Caesarean section - BMI > 40 kg/m2 - Prolonged hospital stay - Intravenous drug user |
VTE prophylaxis for a minimum of 5 days post delivery (or longer duration if still admitted in hospital) |
| Patient with any of the following intermediate risk factors: - Age > 35 years of age - BMI 35-40 kg/m2 - Parity ≥ 3 - Smoker - Elective caesarean section - Any surgical procedure in the puerperium - Gross varicose veins - Current systemic infection - Immobility e.g paraplegia, long distance travel - Current pre-eclampsia - Prolonged labour > 24 hours - PPH† > 1 litre or requiring blood transfusion |
One risk factor: Two or more risk factors: |
†Post-partum haemorrhage
Prophylactic treatment
- Low molecular weight heparin, e.g.
LoE:IIbxlii
- Enoxaparin, SC:
- Body weight <100 kg: 40 mg daily.
- Body weight ≥100 kg: 60 mg daily.
- For post-partum prophylaxis, start 6–12 hours after delivery.
LoE:IIIbxliii
Note:
- Although LMWH related skin reactions are generally rare, they are more common in pregnant women. Monitor injection site for potential skin reactions.
- Women receiving antenatal LMWH should be advised that if they have any vaginal bleeding or once labour begins they should not inject any further LMWH.
- Spinal or epidural anaesthesia should be avoided if possible until at least 12 hours after the previous prophylactic dose of LMWH.
- The use of warfarin for VTE prophylaxis and treatment during pregnancy is not recommended, except in the setting of valvular disease and atrial fibrillation (see: Heart disease in pregnancy).
- Women that were either 1) on long-term anticoagulation with warfarin before pregnancy, or 2) require anticoagulation for 6 weeks post delivery can be converted from LMWH to warfarin postpartum when the risk of haemorrhage is reduced, usually 5–7 days after delivery.
LoE:IIIbxliv
- Initiation of warfarin will require continued anticoagulation with LMWH at prophylactic doses (see above) until the INR is within the therapeutic range:
- Warfarin, oral, 5 mg daily.
- INR should be done after 48 hours, then every 1 to 2 days until the INR is within the therapeutic range of 2-3 (refer to initiation dosing tables in the Appendix II: Prescribing Information for Specific Medicines).
- Adjust dose to keep INR within therapeutic range (refer to maintenance dosing tables in the Appendix II: Prescribing Information for Specific Medicines).
- Monitor INR at week 1, 2, and 4 (more frequent monitoring may be required if INR is out of therapeutic range).
- All women of reproductive age should be on appropriate contraception (see chapter PHC STGs and EML: Family Planning). If a pregnancy is planned, do frequent pregnancy tests and change to LMWH once pregnancy is confirmed.
- For all major elective surgery and other elective procedures with a significant bleeding risk, such as neuraxial anaesthesia and lumbar punctures, the INR should be <1.5.
- Educate patient on signs and symptoms of warfarin toxicity, and on risks associated with drastic dietary changes such as increased consumption of cruciferous vegetables.
- Warfarin is safe in breastfeeding
Acute treatment of VTE or pulmonary embolism:
LoE:IIIbxlv
- Low molecular weight heparin, e.g.
LoE:IIIbxlvi
- Enoxaparin SC, 1 mg/kg every 12 hours.
- Discontinue treatment at least 24 hours prior to delivery, if the delivery time is predictable.
- Continue treatment for 6 weeks post partum, and for at least three months in total.
REFERRAL/CONSULTATION DURING PREGNANCY
- Heparin-induced thrombocytopenia.
- Heritable or acquired thrombophilia.
- Medical comorbidities for consultation with specialist: heart or lung disease, SLE, cancer, inflammatory conditions, nephrotic syndrome, sickle cell disease, anti-phospholipid syndrome.
Standard Treatment Guidelines And Essential Medicines List For South Africa, Adult Hospital level_Version 1_30 March 2026
Chapter 2: Blood and Blood Forming Organs; References