The metabolic clearance rate of dehydroisoandrosterone sulfate (MCRDS) was determined prospectively in gravidas with and without chronic essential hypertension. In normotensive patients, the MCRDS increased in linear fashion throughout pregnancy. In patients with chronic essential hypertension the MCRDS also increased progressively, but at higher values than in normotensive subjects. In normotensive gravidas who ultimately developed pregnancy-induced hypertension, the MCRDS increased progressively at a higher level than in gravidas who remained normotensive until approximately 4 weeks prior to the onset of clinical symptoms, at which time the MCRDS slowly decreased. Similarly, in gravidas with chronic hypertension who developed superimposed pregnancy-induced hypertension, the MCRDS increased progressively at higher levels than all groups studied until approximately 4 weeks prior to onset of hypertension, when a progressive decline in the MCRDS began.