Longitudinal changes in uterine artery Doppler and blood pressure and risk of pre-eclampsia.

Abstract

To investigate longitudinal changes in the uterine artery mean pulsatility index (UtA-PI) and mean arterial pressure (MAP) in women who develop pre-eclampsia (PE) and gestational hypertension (GH). This was a prospective longitudinal study of singleton pregnancies identified by screening at 11 + 0 to 13 + 6 weeks' gestation as being at high risk for PE. Measurements of UtA-PI and MAP were taken every 4 weeks until delivery and were compared in women who developed preterm PE, requiring delivery before 37 weeks, term PE and GH with those in women who remained normotensive. In the normal outcome group, UtA-PI decreased with gestational age and MAP decreased between 12 and 24 weeks and then increased. In the preterm PE group, as compared to the normal group, UtA-PI and MAP were higher from early pregnancy onward and the difference for both increased with gestational age. In the term PE group, UtA-PI was significantly increased only from 33 weeks onward and MAP was increased from 12 weeks onward but the difference from normal did not increase with gestation. In GH, UtA-PI did not differ significantly from normal but MAP was higher from 12 weeks onward. The study describes temporal changes in UtA-PI and MAP in normal pregnancies and in women who develop PE and GH.