Effect of angiotensin II infusion during normal pregnancy on flow velocity waveforms in the uteroplacental and umbilical circulations.

Women destined to develop preeclampsia show an increased systemic pressor response to infused angiotensin II, and the angiotensin sensitivity test has been accepted as an appropriate means of identifying these women. However, the effect of angiotensin II infusion on uteroplacental blood flow is unknown and may be deleterious. Patients undergoing angiotensin sensitivity tests as part of a protocol examining the effect of aspirin on the incidence of preeclampsia were studied with Doppler velocimetry performed before and during the angiotensin II infusion. Fetal well-being was documented with biophysical profiles performed before and after the infusions. Neither the systolic-diastolic ratios in the uterine and umbilical arteries nor the biophysical profile scores were altered significantly (P = .43, P = .23, Wilcoxon signed-rank median test, and P = .35, Fisher exact test, respectively). These findings suggest that the angiotensin sensitivity test does not increase resistance to flow in the uterine or umbilical circulation, and therefore may be used safely in screening for preeclampsia.