It is clear that preeclampsia is not—as previously thought—a uniformly high-resistance, volume-contracted state. Instead, hemodynamic features range from a hyperdynamic state with elevated cardiac output (CO) and increased left ventricular (LV) function to a vasoconstrictive state with decreased CO and reduced LV function. Variable profiles of systemic resistance also have been described.
This prospective observational study used two-dimensional and M-mode echocardiography as well as uterine artery Doppler studies, performed at 11 to 14 weeks’ gestation, to evaluate cardiac function in 534 nulliparous women with singleton pregnancies who presented consecutively to the maternity unit of a teaching hospital for routine antenatal care. In addition to 457 women having a normal outcome there were 8 with preeclampsia but not a small-for-gestational-age (SGA) infant, 19 with preeclampsia and SGA infant, and 50 with SGA infant but not with preeclampsia.
The groups did not differ with respect to maternal age, height, or gestation at the time of enrollment. Women with preeclampsia and SGA infant included a disproportionately high number of black women and women having earlier gestations at delivery. Birth weight centile was significantly reduced in women having an SGA infant. Compared with women having a normal outcome, those with preeclampsia but not with SGA infant had increased CO and mean arterial pressure (MAP). MAP, total peripheral resistance, and the uterine artery pulsatility index (UAPI) were increased in the group with preeclampsia and SGA infant. Total peripheral resistance and UAPI were increased in women with SGA infant but not preeclampsia. Multiple logistic regression analysis identified MAP, stroke volume, and UAPI as independent predictors of preeclampsia. SV and UAPI also were independent predictors of SGA.