Thrombosis in Women: Unique risk in pregnancy and hormone therapy

Our Blood has a unique self-healing property of being able to clot whenever we are injured. This property saves us from bleeding to death after a trivial injury. However, if this property is not kept under control, the blood can clot inside the blood vessels. And this condition of Thrombosis can be life-threatening.

This condition can be seen in pregnancy . In pregnancy not only do we have a hormonal change, but the blood also tends to be a little sluggish as it flows through the placenta and there is a potential for tissue damage which can cause thrombosis inside the patient’s blood vessels.

Deep vein thrombosis during pregnancy, also known as DVT, arises from abnormal blood clotting within the deep veins of the lower legs. A pregnant woman may experience severe leg pain and swelling due to this condition, even after giving birth. An ultrasound Doppler examination can verify a DVT diagnosis through visualization of clots inside the calf or thigh veins. Treatment aims to dissolve existing clots and prevent further coagulation from occurring. However, researchers have found that DVT commonly reemerges during later pregnancies for women who suffered from it previously. The risks must be closely monitored and properly managed throughout any future gestations.



If left untreated, the blood clot in the vein can break away and reach her heart. This can cause sudden death due to obstruction of the blood flow to her lungs.
Similarly, blood can clot in the veins of her brain. This is known as Central Venous Thrombosis (CVT). It causes severe headaches and she may have convulsions. Diagnosis is by a type of MRI and the treatment is usually successful if done without delay and under expert guidance.

It’s possible to prevent these two conditions to a large extent if we ensure that our pregnant women are well-hydrated especially after delivery. We should avoid unnecessary bed rest after delivery unless specified by her doctor. Occasionally, amniotic fluid which normally surrounds the baby, leaks into the mother’s blood supply causing a condition called amniotic fluid embolism. This results in a cascade of nonstop blood coagulation inside the mother’s blood vessels, leading to a complete depletion of all of her coagulation proteins. This will then cause nonstop bleeding from every part of the patient’s body and often she will succumb to this condition. This is known as Disseminated Intravascular Coagulation or DIC. This same DIC may also occur in a case of PPH, where the patient doesn’t stop bleeding after the delivery of her baby. This dreaded complication is unexpected and therefore cannot be predicted. To survive this, she will require tertiary intensive care as well as blood product availability.

Some women have a natural ability to clot a little more than an average normal person. This is called thrombophilia and may be inherited or acquired. The most commonly known type of this condition is known as antiphospholipid antibody syndrome or APLA. Women who suffer from APLA have a higher risk of losing their pregnancies at all periods of gestation. This can be managed by giving the patient daily anticoagulation medications and often we may be able to take the patient to term to a safe and happy delivery.

We need to be aware that hormonal therapy like oral contraceptive pills and hormone replacement therapy may increase the risk of thrombosis. Also, women with hypertension, diabetes, and excessive weight can be considered to be at high-risk for thrombosis, and therefore they too may avoid these medications. If she is on these medications, she should be aware of the inherent risks. She also needs to ensure she is well hydrated and uses compression stockings, especially when on long-duration flights.

So, as we can see the unique life-saving ability of blood to self-heal, in the presence of hormones and pregnancy can also be life-threatening. However, with present-day knowledge and investigatory abilities, these conditions can often be diagnosed and treated successfully.

(Article courtesy: Dr. Deepak Shedde, Senior Consultant – OBG, KMC Hospital Dr.B.R.Ambedkar Circle Mangalore)