Venous thromboembolism (VTE) occurs when a blood clot forms in the vein, blocking blood flow in the area.
Anyone can be inflicted with VTE, but some people, like pregnant women, are at a higher risk.
According to the Statistics Department, obstetric embolism, including VTE, remains the leading cause of maternal mortality in Malaysia.
Between one in 500 and one in 2,000 pregnancies are affected by VTE, more commonly during the six weeks after labour (postpartum period).
The two types of VTE are deep vein thrombosis (DVT) and pulmonary embolism (PE).
DVT is a blood clot that forms in a deep vein, usually in the leg or pelvis, but can also develop in the arm.
Symptoms include swelling, pain, warmth and redness of the skin, but half of cases show no symptoms.
DVT is three times more common than PE during pregnancy.
PE occurs when a DVT breaks off and travels to the lungs.
It is potentially fatal and causes breathing difficulties, chest pains, rapid or irregular heartbeat, bloody coughing, dizziness and fainting.
Pregnancy increases the risk of VTE by four or five times due to blood hypercoagulability in pregnant women – a condition where blood clots more easily to minimise blood loss during childbirth.
Other reasons include venous stasis (where the growing uterus compresses veins around the pelvis) and blood vessel injury during delivery.
All pregnant women must be assessed for VTE risk factors in early pregnancy and after delivery.
They will be categorised into high risk, intermediate risk or low risk groups, and advised to take appropriate preventive measures.
These include taking preventive prescription drugs, moving around constantly and avoiding dehydration by drinking water regularly.
Multiple factors increase VTE risk during pregnancy and postpartum, including:
- Previous VTE
- Family history of VTE
- Age (risk increases with age)
- Inherited clotting disorders
- Certain chronic diseases, e.g. heart or lung disease, cancer, inflammatory conditions and systemic lupus erythematosus (SLE).
- Vein injury, e.g. due to major surgery, fractures or muscle injury.
- Immobility, e.g. due to paralysis, prolonged confinement to bed and long-haul travel.
- Increased oestrogen, e.g. due to birth control pills or hormone replacement therapy.
- Caesarean section
Low molecular weight heparin (LMWH) is the recommended medication for both treatment and prevention of VTE in pregnancy.
Other anticoagulants are less effective, e.g. unfiltered heparin is linked with a higher risk of complications and fondaparinux is not recommended as it can cross the placenta.
However, the porcine origin of LMWH could be a concern among some Muslims in Malaysia.
This may have affected the uptake of LMWH and is possibly one of the factors in the rising death rate of VTE here.
Despite its origins, tests have shown that after extensive processes during production, no more porcine elements are traceable in LMWH.
The drug is used in many Muslim countries aside from Malaysia, due to its benefit and superiority to alternative options, especially for pregnant women.
Muslim scholars agree that LMWH is allowed in a high-risk VTE case as it is regarded as a medical emergency and is required for life preservation.
LMWH treatment should be continued throughout the pregnancy.
However, it must stop either once labour starts or 24 hours before planned delivery.
Treatment should resume after delivery for six weeks, either with LMWH or warfarin (another type of medication).
Both medications are safe for breastfeeding.
For severe cases of VTE, thrombolytic drugs can be used to dissolve the clot and surgery, as a last resort, may be necessary for clot removal.
Compression stockings (special tight socks) may be recommended to help with blood flow and to relieve pain and swelling.
As a preventive measure, the sock should be worn on the affected leg for at least two years after having VTE.
It also reduces the risk of post-thrombotic syndrome – a possible complication that causes pain, discoloration, scaling or ulcers on the affected area, which can lead to disability.
This condition is one of the major risks that pregnant women have to face, and emphasises the need for optimal thromboprophylaxis (use of medication to prevent VTE) and treatment whenever indicated.
Dr H. Krishna Kumar is a consultant obstetrician and gynaecologist, and past president of the Obstetrical and Gynaecological Society of Malaysia. This article is courtesy of the Malaysian Paediatric Association’s Positive Parenting programme in collaboration with expert partners. For further information, please email firstname.lastname@example.org. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.