The objective of the study was to compare maternal hemodynamics in nulliparous women and in parous women with and without previous preeclampsia and/or small for gestational age.
This was a prospective, longitudinal study of maternal hemodynamics, assessed by a bioreactance method, measured at 11+0 to 13+6, 19+0 to 24+0, 30+0 to 34+0, and 35+0 to 37+0 weeks\' gestation in 3 groups of women. Group 1 was composed of parous women without a history of preeclampsia and/or small for gestational age (n = 632), group 2 was composed of nulliparous women (n = 829), and group 3 was composed of parous women with a history of preeclampsia and/or small for gestational age (n = 113). A multilevel linear mixed-effects model was performed to compare the repeated measures of hemodynamic variables controlling for maternal characteristics, medical history, and development of preeclampsia or small for gestational age in the current pregnancy.
In groups 1 and 2, cardiac output increased with gestational age to a peak at 32 weeks and peripheral vascular resistance showed a reversed pattern with its nadir at 32 weeks; in group 1, compared with group 2, there was better cardiac adaptation, reflected in higher cardiac output and lower peripheral vascular resistance. In group 3 there was a hyperdynamic profile of higher cardiac output and lower peripheral vascular resistance at the first trimester followed by an earlier sharp decline of cardiac output and increase of peripheral vascular resistance from midgestation. The incidence of preeclampsia and small for gestational age was highest in group 3 and lowest in group 1.
There are parity-specific differences in maternal cardiac adaptation in pregnancy.