The influence of different positions and Korotkoff sounds on the blood pressure measurements in pregnancy.

The influence of the patient's posture on the measurement of arterial blood pressure has been studied during pregnancy. The blood pressure (BP) measured on the right arm in the left lateral recumbent position is significantly lower than in the supine, sitting, or erect positions. This difference is assumed to be due to hydrostatic factors. The diastolic BP should be read off at Korotkoff IV because the hyperkinetic circulation during pregnancy causes a pronounced variation in BP values when measurements are performed at Korotkoff sound V. The roll-over test seems inappropriate as a screening test to predict pre-eclampsia, because of the numerous false-positive tests. The importance of measuring the BP under standardized conditions during pregnancy in order to detect minimal changes in BP as indicative of pathophysiology in pre-eclampsia is emphasized.