Failure of platelet angiotensin II binding to predict pregnancy-induced hypertension

Objective: To determine whether measurement of platelet angiotensin II bind ing at 20 weeks' gestation identifies women destined to develop pregnancy-i nduced hypertension. Methods: Over a 2-year period, we recruited 325 unselected, normotensive pr imigravidas from the hospital antenatal department after their routine 20-w eek scan appointments. Each woman had a singleton pregnancy, was normotensi ve at the time of entry into the study, and had an unremarkable medical his tory. Ninety-three nonpregnant women were recruited from the hospital staff for comparison. Platelet angiotensin II binding was measured in all partic ipants. After delivery, the case notes were screened to determine pregnancy outcome. Results: Two hundred sixty-seven women remained normotensive to delivery, 3 0 developed nonproteinuric pregnancy-induced hypertension, 23 developed pro teinuric pregnancy-induced hypertension, four had transient hypertension, a nd one was diagnosed subsequently as having essential hypertension. The med ian platelet angiotensin II binding for the nonpregnant subjects was 15.7 f mol/10(9) platelets, which differed significantly from the value for normot ensive pregnant subjects (4.8 fmol/10(9) platelets, P < .001) and from the value for those who developed either nonproteinuric pregnancy-induced hyper tension (4.95 fmol/10(9) platelets) or proteinuric pregnancy-induced hypert ension (7.2 fmol/10(9) platelets, P < .001). There was no significant diffe rence between pregnant women who remained normotensive and those who develo ped nonproteinuric or proteinuric pregnancy-induced hypertension. Conclusion: Measurement of angiotensin II binding in the second trimester h as no value as a screening test for nonproteinuric or proteinuric pregnancy -induced hypertension. (Obstet Gynecol 1999;93:203-6. (C) 1999 by The Ameri can College of Obstetricians and Gynecologists.).