Arteriolar distensibility in hypertensive pregnancy

In order to investigate further the mechanism of the increased resistance in hypertensive pregnancy, a study was made of the ability of forearm vessels to dilate in hypertensive and normotensive pregnancy. Arteriolar response to arterial occlusion and local exercise was studied, by a plethysmographic technique, in 31 normotensive pregnant women and in 39 with either essential hypertension or toxemia of pregnancy. In normotensitive women, the response was unchanged throughout pregnancy and the puerperium. In both toxemia and essential hypertension in pregnancy, there was an increase in peripheral vascular resistance at both resting and peak levels of blood flow. In essential hypertension there was also a slight increase in peak flow. It is concluded that the vessel wall itself may be abnormal in hypertensive pregnancy.