The risk of developing blood clots (thrombophlebitis) is increased for about 6 to 8 weeks after delivery (see Thromboembolic Disorders During Pregnancy). Typically, blood clots occur in the deep veins of the legs or pelvis (a disorder called deep vein thrombosis).
Sometimes one of these clots breaks loose and travels through the bloodstream into the lungs, where it lodges in a blood vessel in the lung, blocking blood flow. This blockage is called pulmonary embolism.
Blood clots may also develop in the veins just under the skin in the legs. This disorder is called superficial venous thrombosis (superficial thrombophlebitis).
A fever that develops after delivery may be caused by a blood clot.
When a blood clot forms in a leg vein, the affected part of the leg, often the calf, may be painful, tender to the touch, warm, and swollen. A blood clot in the pelvis may not cause symptoms.
The first sign of pulmonary embolism may be shortness of breath.
Doctors can usually diagnose superficial blood clots based on a physical examination.
Diagnosis of deep vein thrombosis is usually based on results of ultrasonography. Occasionally, a blood test to measure D-dimer (a substance released from blood clots) is helpful.
If pulmonary embolism is suspected, computed tomography (CT) of the chest is done after a radiopaque contrast agent is injected into a vein. The contrast agent makes the blockage easier to see.
Treatment of a superficial blood clot in the leg consists of warm compresses (to reduce discomfort), compression bandages applied by a doctor or nurse, and, when resting, elevation of the affected leg (for example, by raising the foot of the bed 6 inches). Rarely, when the superficial blood clots are extensive, women are given drugs that make blood less likely to clot (anticoagulants, which are sometimes called blood thinners).
Women with deep vein thrombosis or pulmonary embolism need to take anticoagulants, which make blood less likely to clot. Sometimes doctors place a filter in the inferior vena cava (the vein that carries blood from the lower part of the body to the heart). The filter prevents a blood clot from the leg moving to the lungs. Rarely, surgery to remove the clot is necessary.