DVT (Deep Vein Thrombosis) in Pregnancy

Along with many physiological changes in the body during pregnancy, an increase in the susceptibility to Deep Vein Thrombosis(DVT) is also found in many women. Veins are tubes that transport blood in the body, and blockage in these veins is termed as venous thrombosis. During pregnancy, a woman has a six times higher chance of developing such a clot in the vein, compared to a non-pregnant woman. Learn about the various aspects of DVT, its causes, symptoms, treatment and prevention.

What is Deep Vein Thrombosis (DVT)?

In deep vein thrombosis, clotting of blood occurs in the veins found in the leg and pelvic region. Clotting of blood is a normal physiological process in the body and occurs when there are any cuts or openings in the blood vessel. In the case of DVT, this occurs inside the vein, constricting the flow of blood resulting in serious implications, if left unidentified. Thrombosis in pregnancy is caused by an increase in the blood clotting capacity of the body during pregnancy, as a means of preventing excessive blood loss during delivery. This can sometimes result in a blood clot in the leg during pregnancy.

How Common is DVT During Pregnancy?

DVT during pregnancy is not very common and occurs in only one in thousand pregnant women. The risk of developing DVT is six times more in a pregnant woman, with an increased chance of occurrence in the first trimester of pregnancy and six weeks post-partum.

Why is It More Common When Pregnant?

The body experiences numerous physiological changes during pregnancy. These changes are mostly driven by variations in the hormonal levels. One reason is one of the safety precautions that a woman’s body takes during pregnancy, which is an increase in the clotting proteins and a decrease in the anti-clotting proteins, to minimize blood loss during delivery. Another factor that can contribute to this condition is pressure exerted by the enlarged uterus on the veins which carry blood to the heart from the lower body.

Causes of DVT

DVT during pregnancy is primarily caused by the hormonal changes the body undergoes during this period.

1. Oestrogen

During pregnancy, the circulating levels of oestrogen hormone are high in the blood, which in turn increases the chances of a blood clot.

2. Uterine Growth

The expansion of uterus that occurs with the development of the foetus, puts a lot of strain on the veins carrying blood back from the lower body to the heart. This also results in clotting of blood inside the veins returning from the extremities.

3. Increase in Body Weight

Excessive weight gain puts a lot of pressure on the veins of the legs and pelvis, leading to increasing the chances of having a DVT.

4. Multiple Pregnancy

Mothers carrying more than one foetus in their womb have a higher risk of developing DVT.

5. Age and Genetics

Women who have a family history of DVT or are expecting a baby at 35 years of age or more are at risk of experiencing venous thrombosis during pregnancy.

DVT Sign and Symptoms

Women who develop DVT during their pregnancy have one or more of the following symptoms:

• Pain in one leg accompanied by swelling
• Visibly enlarged veins
• Pain while walking
• The feeling of tenderness in the thighs and calf muscle

Diagnosis

Based on the symptoms and previous family history of DVT, the medical practitioner usually performs a Doppler ultrasound examination to check for any venous blocks. The Doppler ultrasound estimates the speed of blood flow in the veins and flags the areas that have reduced flow. The diagnosis of DVT can be very tricky, and in some cases, the doctor may prescribe a D-dimer test. This test works by identifying the presence of any blood clots in the blood vessels.

To quantify and characterize the block, doctors also carry out a venogram, in which a dye is injected into the veins to help in clearly visualizing the blockages.

Who is Most At the Risk of Getting DVT?

Pregnant women who have one of the following risk factors have an increased susceptibility to developing DVT.

• A family history of DVT
• Previous history of DVT
• Age above 35 years
• Obesity or weight gain
• Women who travel long distances during pregnancy
• Smoking
• Inactive lifestyle
• Multiple pregnancies
• C-section delivery
• Clotting or inflammation due to infection in pregnancy

Treatment of DVT in Pregnancy

Once a diagnosis of DVT during pregnancy is made, the doctor usually prescribes medications to thin the blood. This medication is continued after delivery up to at least six weeks post-partum, as there are chances of block formation even after the birth of the baby.

Does Deep Vein Thrombosis Affect the Baby?

Typically, DVT causes discomfort to the mother but does not affect the baby’s growth and development. Rare situations where the block moves up till the lungs, affecting its function, it can hamper the oxygen supply to the foetus. Also, during delivery, when the mother loses excessive blood because of the blood thinners, it can affect the baby.

Management

Management of DVT during pregnancy is possible with heparin injections. Heparin is an anticoagulant that inhibits the clotting of blood. Apart from the medication, some lifestyle changes like adopting an active routine, reducing body weight and quitting smoking can also largely prevent the further clotting of blood.

A special kind of compression stockings can be worn to improve the blood circulation in the leg. Apart from that, drinking lot of water and exercising also helps in managing DVT.

How to Reduce the Risk of DVT While Travelling?

The chances of the symptoms of DVT flaring up is high during travel. To reduce the risk while travelling, take precautions like increasing your water intake, ensuring constant movement of the lower body either in the sitting position itself or by walking within the vehicle, and completely avoiding the intake of alcohol.

Can Deep Vein Thrombosis Affect Labour?

If you have been identified to have a tendency to develop DVT, then the doctor would advise you to take some precautions before the delivery. To reduce the risk of developing thrombosis during labour, you can wear the compression stockings while constantly moving around and drink lots of fluids before going to deliver the baby.

If you have already been diagnosed and are on heparin medications, the doctor may ask you to discontinue it as it can interfere with the clotting of blood after delivery.

Can Caesarean Delivery Increase Risk of Getting Blood Clots?

Yes, a C-Section delivery is shown to increase the risk of post-partum blood clots, as compared to a vaginal birth. This is because the body takes necessary precautions and mobilizes its healing mechanisms for an invasive procedure, one of which is an increase in the propensity of the blood to clot.

Prevention

Some of the ways by which you can prevent the occurrence of DVT during pregnancy are,

1. Drinking Lots of Water

Fluid intake is very important in the prevention of DVT as dilutes the blood and prevents it from becoming very thick. This has to be followed throughout pregnancy and even after the delivery to prevent the formation of blood clots.

2. Exercising

If you are at the risk of developing thrombosis during pregnancy, then practising light and safe exercises regularly can immensely help in improving the blood circulation to the body. Exercises that particularly benefit the circulation of the lower body can be helpful in preventing DVT.

3. Move on the Go

If you are having DVT and have to travel long distances on a regular basis, then try to move around inside the bus, flight or train every few minutes to break the resting period. This keeps the circulation alive. If getting up and moving around is not a possibility, then try to do simple twisting and moving exercises in sitting position itself.

4. Wear Stockings

Compression stockings that activate the blood circulation in the leg can be worn during pregnancy and even during labour to avoid clot formation.

DVT is a common condition in pregnancy that many women lack awareness about. It is easily treatable with medications and identifying it at the right time is the key to have a safe and healthy pregnancy.