Angiotensin II levels in hypertensive and normotensive pregnancies. We measured circulating angiotension II by radioimmunoassay in women with pregnancy-induced hypertension (n = 54), and compared these values with those obtained in women with normal pregnancy (n = 18) and in non pregnant women (n = 20). Pregnant women had statistically significantly higher plasma angiotensin II [mean (SD): 41.3 (12.6) pg/ml] than non-pregnant women [29.2 (11.3) pg/ml; P less than 0.004]. Angiotensin II concentrations in women with pregnancy-induced hypertension [mean (SD): 31.7 (16.2) pg/ml] were, on average, 25% lower than in normal pregnancy (P less than 0.003) and resembled those obtained in non-pregnant women. The lowest angiotensin II levels were found in women with more severe forms of pregnancy-induced hypertension, such as proteinuric or superimposed pregnancy-induced hypertension. Review of the published studies on angiotensin II and our data suggest that the conflict among studies on angiotensin II levels in pregnancy-induced hypertension is largely due to the heterogeneity of the study populations in the various reports. 