[Study of peripheral resistance in pregnant women. Preliminary results]

Variations in blood pressure (BP), heart rate (HR) and peripheral arterial blood flow (BF) were measured during the "roll-over" test (ROV) by impedance plethysmography. With these parameters, the peripheral vascular resistance (PR) was estimated in 17 normotensive and 8 hypertensive women between 28 and 32 weeks of pregnancy. In the normotensive women, a mean drop of 10.97% in BF and mean increase of 49.85% in PR were observed. Chronic hypertensive women with good evolution during pregnancy had a 96.30% (p less than 0.01) drop in their BF and a 399.38% (p less than 0.01) increase in their mean PR. Changes in BF and PR in chronic hypertensive women with obstetrical complications were similar to the normotensive women: BF increased by 4.50% and PR decreased by 0.04%. The increase in PR in the normotensive group could be due to a release of circulating vasopressive agents. In the chronic hypertensive group without complication this release could be more important or there might be an increase in the peripheral vascular sensitivity. In contrast, the lack of variation in PR in the chronic hypertensive group with obstetrical complications could be due to already established arterial vasospasm.