A 40 year old female patient complains of swelling on both legs. Patient is pregnant (3rd trimester). Which of the following statements about the type of thrombosis that is most likely to be present in this patient is true?
**Core Concept**
During pregnancy, the risk of venous thromboembolism (VTE) increases due to hypercoagulability, venous stasis, and vascular wall injury. The most common type of thrombosis in pregnant women is deep vein thrombosis (DVT), which is often associated with venous thromboembolism.
**Why the Correct Answer is Right**
In the third trimester of pregnancy, the increased pressure on the veins in the legs, combined with the hypercoagulable state, leads to a higher risk of DVT. The venous stasis is caused by the compression of the inferior vena cava by the expanding uterus, which reduces blood flow back to the heart. The hypercoagulable state is due to the increased levels of clotting factors and the decreased levels of anticoagulant proteins. The resulting thrombosis is most likely to be a venous thrombosis, specifically a DVT.
**Why Each Wrong Option is Incorrect**
**Option A:** Pulmonary embolism (PE) is a possible complication of DVT, but it is not the type of thrombosis itself. DVT is the formation of a blood clot in the deep veins of the legs, while PE is the blockage of an artery in the lungs by a blood clot that has traveled from the legs.
**Option B:** Arterial thrombosis is less common in pregnancy compared to venous thrombosis. The hypercoagulable state during pregnancy is more likely to lead to the formation of blood clots in the veins rather than the arteries.
**Option C:** Thrombophlebitis is inflammation of a vein caused by a blood clot. While it is possible in pregnancy, it is not the most likely type of thrombosis, which is DVT.
**Clinical Pearl / High-Yield Fact**
Pregnant women, especially those in the third trimester, are at increased risk of VTE due to the hypercoagulable state and venous stasis. It is essential to be aware of this risk and monitor patients closely for signs and symptoms of DVT, such as swelling, pain, and warmth in the legs.
**Correct Answer:** C.