PP078. The influence of maternal position on gestational hemodynamics

Cardiovascular profiling is useful for gestational hemodynamic studies. Conflicting results of cardiac output evolution from third trimester pregnancy to term are frequently reported.

To stress the effect of maternal position in the assessment of maternal cardiac and arterial parameters during normal pregnancy.

Impedance cardiography measurements were executed during 16 normal pregnancies using a standard protocol with known reproducibility. Gestational evolution of stroke volume, cardiac output, cardiac cycle time intervals, aortic flow parameters and total peripheral vascular resistance was measured in supine, standing and sitting positions. SAS procedure MIXED for linear mixed models was used for each parameter separately.

Evolution of stroke volume and cardiac output in supine position differed from standing (p<0.01) and sitting positions (p<0.05). Next to this, pre-ejection period, left ventricular ejection time index, systolic time ratio and total peripheral vascular resistance also showed a different evolution between supine and standing positions (p<0.05); no differences were observed between standing and sitting positions (p⩾0.19).

Next to the frequently reported cardiac output, gestational evolutions of other pre-load dependent parameters are influenced by maternal position. This study shows the importance of a standardized protocol for the measurement of cardiovascular parameters in pregnancy.