Venous Distensibility During Pregnancy

Preeclampsia is associated with increased peripheral resistance. This study was performed to determine whether an increase of venous distensibility occurs as well in preeclampsia. We obtained venous distensibility by measuring the venous pressure-volume relation in the forearm with a water-filled plethysmograph. Twenty-one women with normal pregnancy, 12 women with severe preeclampsia, and 8 women with mild preeclampsia were studied during the third trimester and/or 6 weeks after the delivery. Ten nonpregnant normotensive women were also studied. Venous distensibility was greater (P<.01) in normal pregnant women and smaller (P<.01) in women with preeclampsia during pregnancy than postpartum. The magnitude of the decrease of venous distenNormal pregnancy is characterized by arterial ' and venous' vasodilation and by increased intravascular volume.' In contrast, preeclampsia is associated with increased peripheral resistanceand decreased intravascular volume.' Changes in venous distensibility in women with preeclampsia are less well documented. The venous system may be important in control of intravascular volume and blood pressure. It has been documented that essential and borderline hypertension are associated with decreased venous distensibility. Decreases in venous distensibility shift the intravascular volume from the peripheral to the central circulation. Thus, it is possible that impaired venous distensibility may contribute to altered hemodynamic status in preeclampsia. Several previous investigators examined venous distensibility in women with preeclampsia. Weinstein et al and Hunyor reported no difference between normal pregnancy and preeclampsia. Stainer et al reported decreased venous distensibility during preeclampsia. However, this study was cross-sectional, and they did not examine whether it was reversible postpartum. Pickles et al reported increased venous distensibility during preeclampsia. Thus, the reported results are variable. The aim of this study was to further evaluate peripheral venous distensibility in preeclampsia during Received August 3,1993; accepted in revised form May 4, 1994. From the Department of Gynecology and Obstetrics (K.S., H.M., H. Nagata, K.T., H. Nakano) and Research Institute of Angiocardiology and Cardiovascular Clinic (T.I., A.T.), Faculty of Medicine, Kyushu University, Fukuoka, Japan. Correspondence to Tsutomu Imaizumi, MD, Research Institute of Angiocardiology and Cardiovascular Clinic, Faculty of Medicine, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812, Japan. © 1994 American Heart Association, Inc. sibility correlated with the severity of preeclampsia. Venous distensibility was similar between normotensive nonpregnant women, women with nonnal pregnancy during the postpartum period, and women with preeclampsia during the postpartum period. Thus, venous distensibility increased during nonnal pregnancy. In preeclampsia, the decrease of venous distensibility occurred during pregnancy but was reversed postpartum. These results may suggest that a decrease of venous distensibility occurs during preeclampsia. These venous abnormalities may contribute to impaired control of hemodynamics in preeclampsia during pregnancy. (Hypertension. 1994;24:461-466.)