Pulmonary Embolism in Pregnancy


Pulmonary embolism is one of the most common causes of death during pregnancy. A pulmonary embolism is the occlusion of one or more vessels in the lungs with a blood clot (thrombus). The circulatory disorder hinders the exchange of oxygen in the lung tissue and the patients suffer from severe shortness of breath. The risk of pulmonary embolism increases as pregnancy progresses as the risk of thrombosis increases.


The blood clot that leads to pulmonary embolism almost always results from deep vein thrombosis (DVT). The clot separates from the leg vein and is washed into the lungs via the bloodstream, where it clogs the pulmonary vessels.

Pregnancy is a risk factor for the development of a pulmonary embolism. Blood coagulation is changed in pregnant women in order to be able to stop possible bleeding more quickly during the upcoming birth process. Due to the increased tendency to clot, however, the risk of a thrombosis also increases as the pregnancy progresses. Women in the puerperium also have an increased risk of thrombosis.

Lack of exercise further increases the risk of pulmonary embolism, especially in the second half of pregnancy. Other factors that further increase the risk of coagulation are congenital bleeding disorders, smoking, obesity, tumor diseases or long bed rest and immobilization. A history of thrombosis also increases the risk of pulmonary embolism.

More on this:

  • Causes of Pulmonary Embolism

Clotting disorders

Women who suffer from a hereditary coagulation disorder (also referred to medically as coagulopathy) have a significantly higher risk of deep vein thrombosis and, as a result, a pulmonary embolism during pregnancy.

In addition, the risk of a miscarriage is also increased in this case, since thromboses can form on the placenta. Factor V disease (APC resistance) is one of the most common blood clotting disorders. Regular blood tests, in which the blood clotting is examined, should be carried out in the case of mutation carriers during pregnancy. It may be necessary for those affected to also take anticoagulant medication.

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How often does a pulmonary embolism occur during pregnancy?

During pregnancy and shortly after birth, the risk of thrombus formation is significantly higher: one person out of 1,000 will suffer a pulmonary embolism, so the risk is 0.1%.

The general risk of thrombosis due to pregnancy is eight times higher than that of non-pregnant women. Pregnant women who give birth by caesarean section are even more at risk of thrombosis due to the surgical procedure than women who give birth naturally. Pulmonary embolism is one of the leading causes of death during pregnancy in Germany.

Important information on this topic:

  • Prevention of pulmonary embolism

Pulmonary embolism can be recognized by these symptoms

Typical symptoms caused by a pulmonary embolism include acute shortness of breath (dyspnoea) and possibly chest pain. The heart rate is significantly increased and the affected women feel dizzy, although brief fainting spells can occur. The majority of pulmonary embolisms are flare-ups, with symptoms onset, resolving, and starting again.

In some cases, symptoms of deep vein thrombosis (DVT) appear before the pulmonary embolism develops. The leg feels heavy and thick on the affected side, and women feel painful burning and pulling in the calf area. However, DVT often does not cause any symptoms and therefore goes undetected.

In any case, if the symptoms mentioned above occur, an immediate medical evaluation should be carried out.

Further information on this:

  • Recognize signs of a pulmonary embolism

What are the risks for the baby?

Because of the high mortality rate from pulmonary embolism, there is a high risk for the unborn child.

Women who are prone to increased thrombus formation also run the risk of a blood clot clogging the placenta and thereby restricting or completely interrupting the child's oxygen exchange. This can lead to a miscarriage.


A thrombosis can easily be treated with anticoagulant drugs (anticoagulants such as low molecular weight heparin). The medication must be taken for the remainder of the pregnancy up to six weeks after the birth. In severe cases, the thrombus must be removed surgically.

If a thrombosis goes unnoticed, in the worst case a pulmonary embolism develops. This is a potentially life-threatening disease that requires immediate medical attention. The patients are treated immediately with high-dose, anticoagulant medication and have to keep strict bed rest. If the course is severe, it may be necessary to have the blood clot surgically removed from the lungs.

The risk of pulmonary embolism can be significantly reduced during pregnancy through appropriate prevention. The precautionary measures include wearing thrombosis stockings: the compression of the leg veins prevents thrombus formation. Pregnant women who have other risk factors for increased blood clotting, for example, being very overweight, smoking, being bedridden or a congenital coagulation disorder should have their doctor examined closely and possibly take blood-thinning medication for the duration of the pregnancy.


A pulmonary embolism is an absolute emergency that must be recognized and treated quickly, otherwise cardiovascular failure and death can occur quickly. The doctor asks the patient about risk factors and performs a physical exam.

Based on the results, the doctor uses the so-called Wells Score to estimate the likelihood of a pulmonary embolism and then decides how to proceed. An EKG or ultrasound of the heart can show signs of right heart strain due to the backlog of blood. In addition, blood is drawn and a certain parameter, the D-dimers, is determined, which can be found in fresh DVT and pulmonary embolism.


The prognosis of pulmonary embolism during pregnancy depends on several factors.

These include the severity of the disease, the age of the patient and how quickly treatment was initiated. Untreated pulmonary embolism has a high mortality rate and 8% of patients die even with adequate therapy. About 30% of patients who have survived a pulmonary embolism retain permanent lung dysfunction.

Also read:

  • Consequences of a pulmonary embolism
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The duration of a pulmonary embolism varies greatly from person to person and is therefore difficult to predict. With appropriate treatment, the blocked pulmonary vessels open up within a few days. Nevertheless, patients must take care of themselves and keep strict bed rest, otherwise there is a risk of relapse.