Figure 5.

Longitudinal changes in cardiac output and peripheral resistance, expressed as a product of 12-week measurements, reported in normal pregnancies [125], early-onset preeclampsia [114], late-onset preeclampsia type I (cross over) [38], and late-onset preeclampsia type II (high output) [37]. In normal pregnancies, the cardiac output increases to a plateau from the second trimester until term, whereas the total peripheral resistance reaches a nadir in the early third trimester to increase again until term [125]. Early-onset preeclampsia presents with high total peripheral resistance from the first trimester onward, combined with a poor increase in cardiac output [114]. Late-onset preeclampsia type I presents with a normal change in peripheral resistance, but a more pronounced increase in cardiac output until the third trimester, when a fast crossover occurs from a high output/low resistance circulation to a low output/high resistance circulation [38]. Late-onset preeclampsia type II shows high cardiac output and low peripheral resistance throughout all stages of pregnancy in a population of mainly obese women [37].