[22-OR]: Maternal systemic circulation in normotensive pregnancies and those complicated by preeclampsia.

OBJECTIVES: Maternal cardiac adaptation to pregnancy is important in maintaining normal uteroplacental perfusion. These changes could potentially explain the different clinical phenotypes associated with impaired placentation and could potentially be used to guide therapy. The aim of this study was to investigate the changes in the maternal systemic circulation in normotensive pregnancies and those complicated by pre-eclampsia (PE).

METHODS: This was a prospective case-control study in singleton pregnancies recruited after 20 weeks' gestation, some of whom developed PE and some of whom remained normotensive. The diagnosis of PE was made according to the guidelines of the International Society for the Study of Hypertension in Pregnancy. Maternal cardiac index (CI), systemic vascular resistance index (SVRI) and inotropy, which is a measure of myocardial contractility, were assessed using a continuous-wave Doppler ultrasound technique (USCOM®). Mann-Whitney test and regression analysis were used for statistical analysis.

RESULTS: We recruited 153 women with pregnancies complicated by PE and 458 normotensive controls. In the normotensive pregnancies, CI and inotropy were negatively correlated with gestational age (GA) (r=0.21; p<0.001 and r=-0.15; p=0.003, respectively), while SVRI was positively correlated with GA (r=0.20; p<0.001). Compared to controls, pregnancies complicated by PE had significantly lower CI (median 3.30L/min, IQR 2.73-3.81 vs. 3.50L/min, IQR 3.0-4.07, p<0.001), higher inotropy (median 1.87W/m2, IQR 1.61-2.25 vs. 1.65W/m(2), IQR 1.42-1.93, p<0.001) and higher SVRI (median 2678 dynes-s/cm(5), IQR 2238-3269 vs. 2027 dynes-s/cm(5), IQR 1667-2413, p<0.001).

CONCLUSIONS: These findings suggest that in normal pregnancy the maternal myocardial contractility and function correlates with gestational age in the second half of pregnancy. Using this non-invasive technique of assessing maternal systemic cardiovascular function, we demonstrated the changes in pregnancies complicated by PE, including an increase in systemic vascular resistance and decline in cardiac function. These findings suggest that beta-blockade as antihypertensive therapy should be avoided in these cases.

DISCLOSURES: A. Khalil: d. Research Support Recipient; Commercial Interest(s):; USCOM, Roche, Alere, Q-fFN, NICOM. f. Speaker; Commercial Interest: Roche.