Pregnancy is a risk factor for development of varicosis. The reason remains unclear. Because of the secondary diseases like thrombosis, pulmonary embolism and chronic cardial and respiratory diseases treatment of risk factors is important. Therefore we examined 54 patients with sonography and venous occlusion plethysmography before and immediately after delivery. Some of the patients could be reexamined one month and one year following delivery. All veins had a significant exaggerated distensibility post partum. Other functional parameters were not changed. In another study 50 primiparae and 50 multiparae before and after childbirth and 100 women between age 40 and 50 had been examined with light reflection rheography. Pregnancy per se had a negative influence on venous function. Phlebological status had to be included into prenatal care.