Figure 3.

Schematic presentation of the gradual deterioration of circulatory dysfunction from the first to third trimester in early-onset preeclampsia, late-onset preeclampsia, and gestational hypertension (adapted from [114]). The circulation is presented as a closed circuit, with interdependently functioning components. The depicted icons in the circuit represent the sites/organs where abnormal hemodynamic characteristics are measured using noninvasive impedance cardiography, bioimpedence spectrum analysis, and combined ECG/Doppler ultrasonography [114]. Early gestational dysfunctions in the first trimester gradually increase throughout the course of the pregnancy, and this co-exists with the expansion of body water volumes [111]. The final end stage, defined as early-onset preeclampsia, late-onset preeclampsia, or gestational hypertension, depends on the type of hemodynamic dysfunction already present in the first trimester. Note that abnormal Doppler characteristics of the hepatic and renal interlobar veins are observed in preeclampsia but not in gestational hypertension.