The location of chronic pregnancy hypertension on the vasoconstriction-volume spectrum: Working hypothesis,

Objective: The purpose of this study was to examine whether volume loading is a factor in chronic pregnancy hypertension. Study Design: Five patients with chronic hypertension performed home self-monitoring daily with a noninvasive pressure transducer from a fingertip. Determinants of mean arterial pressure were computed from the pressure data and a concurrent electrocardiogram. For this study blood pressure and rapid ejection time, which is an empiric indicator of arterial compliance, were evaluated during antihypertensive therapy. Data were transmitted by facsimile to the hospital. Results: One patient with hypertension who was admitted to the study at 10 weeks’ gestation became normotensive with a diuretic (furosemide) alone. Medication was discontinued at 23 weeks’ gestation. This patient remained normotensive until delivery at 41 weeks’ gestation. Blood pressure was controlled with furosemide combined with nifedipine and labetolol in the other 4 cases. Three patients were studied with concurrent blood pressure and rapid ejection time measurements made before and after antihypertensive medication. All 3 showed decreases in these measurements with medication. Conclusion: Both volume excess and vasoconstriction should be considered in the pathogenesis of chronic pregnancy hypertension. (Am J Obstet Gynecol 1999;181:137-42.)