[Effect of maternal postural change on maternal hemodynamics in late pregnancy--supine hypertension]

The purpose of this investigation was to ascertain the effect of postural change in late pregnant women from the left lateral recumbent position to the supine position on their blood circulation. Patients in whom the blood pressure at the right upper limb in the supine position increased by at least 20mmHg or more (diastolic and/or systolic pressure) were classified as the supine hypertensive group. Patients in whom the blood pressure of the right upper limb decreased by at least 20mmHg or more were classified as the supine hypotensive group. And other patients were classified as the no blood pressure change group. The results were as follows. 1. The incidence of supine hypertension was 48% in primigravidas and 38% in multigravidas. Supine hypertension was especially common in PIH (pregnancy induced hypertension) complicated women (75%). 2. Maternal cardiac function: With postural change from the left lateral recumbent position to the supine position, CO (cardiac output) decreased and SVR (systemic vascular resistance) was increased in both the supine hypertensive and the no blood pressure change groups by the thermodilution method (n = 14). CVP (central venous pressure) and PCWP (pulmonary capillary wedge pressure) shows different pattern of change in the supine hypertensive group and the no blood pressure change group. In the former group, CVP was decreased by 45 +/- 16% and PCWP was increased by 21 +/- 9% in the supine position compared with in the left lateral recumbent position. However, in the latter group, CVP decreased by 87 +/- 69% and PCWP decreased by 53 +/- 46% as the result of the same postural change.(ABSTRACT TRUNCATED AT 250 WORDS)