Archive for April, 2013

Pregnancy and Venous Disease

April 24th, 2013

Maternity Compression Stockings

While pregnancy unquestionably is one of the most joyous, profound and miraculous times in a woman’s life, it unfortunately may be one of the most dangerous as well. Pregnancy creates the PERFECT PHYSIOLOGIC STORM for creating damaging and even dangerous venous problems in the legs.

The blood volume in a woman doubles during her pregnancy and the pelvic circulation increases by 6000%. This produces extraordinary stress on the leg veins attempting to return the extra blood volume uphill, against gravity back to the heart. In addition, the expanding uterus places external compression on the larger pelvic veins which in turn produce increased resistance for blood trying to “drain up and out “ of the leg. Venous blood in the legs normally requires a functioning system of one-way valves and muscular pumps to return the blood uphill back to the chest.

During pregnancy, there are active hormones, progesterone, estrogen and relaxin that are secreted in large quantities and each has a direct deleterious effect on both the vein valves and the vein walls themselves. Progesterone and estrogen weaken the venous valves and stretch the walls making the leg veins less competent which encourages blood to pool in the legs causing swelling. Relaxin, another hormone secreted during pregnancy, has a similar effect–compounding the problem of blood in the legs returning back to the heart. This effect on collagen may also be seen on the skin during pregnancy where there is a gradual loosening of skin on the breast and abdomen during the third trimester.

In as much as the extra stress placed on the leg veins by the increased circulating blood volume and loss of competency of the vein valves and stretching of the vein walls are damaging enough, these changes are pale compared to the potential dangerous hypercoagulable state that is created during pregnancy. Multiple clotting factors increase during pregnancy as well as do the platelets which produce a pro-thrombotic state (pro-clotting).

This places a pregnant woman at risk of developing blood clots in the legs which tragically may result in the clot moving into the lungs and causing death. Pulmonary embolism is a major cause of death during and for several months after pregnancy. This hypercoagulable state, compounded by the enlarging uterus and extra blood volume pooling in the leg veins is a set-up for the venous blood to clot. This hypercoagulable state extends well into the postpartum period for several months extending the risk of pulmonary embolism and death.

There are several important measures that can be taken to mitigate the damage to the leg veins during pregnancy and reduce the risk of leg clots. The importance and use of compression hose during the nine months cannot be overstated. Compression promotes the drainage of blood out of the leg, reducing leg edema, and decreasing the chance of developing blood clots. Compression hose very likely supports the strength of the vein walls and reduce the risk of developing varicose veins. Most stocking companies offer a variety of compression garments designed to apply a specific amount of pressure on the legs depending upon the clinical circumstance. This includes specifically designed “maternity” compression panty hose, for example the SIGVARIS Maternity Line of Compression Stockings. Exercise during pregnancy is very important as well, since the calf muscle is an active pump which helps eliminate pooling and promotes venous drainage “uphill“ and out of the legs. Lastly, elevating the feet and legs whenever possible helps to decrease venous pressure and reduces leg and ankle swelling.