Thirteen pregnant women with pregnancy induced hypertension (PIH) in the third trimester, and eleven normotensive women in the third trimester were given 0.3 mg of the novel dihydropyridine calcium antagonist isradipine intravenously (iv). After drug administration, maternal systolic and diastolic blood pressure (SBP and DBP) decreased in both PIH patients and controls. In the hypertensive patients SBP was reduced from a mean of 150 to 124 mmHg (p 0.5). Corresponding figures for DBP were 99 to 83 mmHg (p