The value of the angiotensin sensitivity test in the early diagnosis of hypertensive disorders in pregnancy.

Normal pregnant women are resistant to the pressor effect of intravenously administered angiotensin II (AII), but women who are destined to develop hypertensive complications in pregnancy show an increased sensitivity to AII several weeks before the onset of the first clinical symptoms. In 231 normotensive nulliparous women (age 25 +/- 5 years), an angiotensin sensitivity test (AST) was performed between weeks 28 and 32 of gestation. If an effective angiotensin pressor dose (APD) of less than 10 ng . kg-1 . min-1, is considered to be a positive test result, 58 subjects had a positive AST and 173 had a negative AST. Twenty-six of 34 women who ultimately developed pregnancy-induced hypertension (PIH) or preeclampsia had a positive test, and the diagnosis was made early. Each of the eight pregnant subjects with a false negative test developed only a mild form of the hypertensive disorder. In this series, 11 women had a premature onset of labor; eight of them also had an APD of less than 10 ng . kg-1 . min-1. The study confirms the high predictive value of negative test results. Therefore, the AST can be used as an appropriate method for identifying women who are destined to develop hypertensive complications in pregnancy. However, because of the low practicability of the test, it may not be recommended as a screening method in routine prenatal care.