[The influence of pregnancy on the venous return from the lower extremities (author's transl)].Med Klin. 1976 Jan 09; 71(2):56-9.MK
Determination of intravenous pressure in the lower extremities revealed in 77 pregnant women a marked insufficiency of the venous drainage. In the last third of pregnancy the capacity of the venous drainage is reduced by approximately 30 per cent. Determination two to five days post partum showed a significant improvement but not yet complete normalization. The causes of the insufficiency of the venous drainage are hormonal influences, dilating the vessels, which are still active post partum. The insufficient venous return is a major factor in the genesis of varicosity during pregnancy. The disturbance of venous return by the large uterus will result in an increase of static venous pressure on the average of 10 mm Hg. In the upright position this is a qualitatively as well as quantitatively individually variable phenomenon. There ist no relation between the increase in static venous pressure and the occurrence of varicosity.