The effect of pregnancy on the compliance of large arteries and veins in healthy parous control subjects and women with a history of preeclampsia

OBJECTIVE: Early pregnancy is characterized by a fail in total peripheral v ascular resistance. In this study we tested the hypothesis that this phenom enon is accompanied by rising compliances of the large arteries and veins. STUDY DESIGN: In 42 women with a history of preeclampsia and 10 healthy par ous control subjects we measured the following variables in the midfollicul ar phase and the midluteal phase during the menstrual cycle and again at 5 and at 7 weeks of amenorrhea: cardiac output, mean arterial pressure, carot id and femoral artery compliances, and venous compliance. The total periphe ral vascular resistance was determined as the ratio of mean arterial pressu re and cardiac output. After screening for thrombophilia and hypertension, women with a history of preeclampsia were divided into subgroups with hyper tension, thrombophilic disorders, and no underlying abnormalities. RESULTS: In parallel with the fail in total peripheral vascular resistance during early pregnancy, femoral artery compliance and venous compliance inc reased in the control group. Except for venous compliance, these changes we re also observed in the women with thrombophilia and a history of preeclamp sia. In the subgroups of the women with a history of preeclampsia with hype rtension and with no underlying disorder both arterial and venous complianc e failed to increase despite a drop in total peripheral vascular resistance . CONCLUSION: These data support the concept that during normal pregnancy the fall in total peripheral vascular resistance is paralleled by improved mac rovascular compliance. The latter adaptive change did not occur in women wi th a history of preeclampsia with hypertension or without an underlying dis order.