Use of the USCOM® noninvasive cardiac output measurement system to predict the development of pre-eclampsia in hypertensive pregnancies.

OBJECTIVES: To assess the ability of the USCOM® (USCOM), using measurements of cardiac output (CO) and systemic vascular resistance (SVR), to predict the development of pre-eclampsia (PE) and severe PE in hypertensive pregnancies.

STUDY DESIGN: Prospective cohort study of women in the second or third trimester recruited at a tertiary center in Sydney, Australia. Demographic data and hemodynamic measurements using the USCOM were taken for all study participants at recruitment. Pregnancy outcome, including development of PE and severe PE, was tracked. Data were analyzed using ANOVA testing, pair-wise comparison testing, and Student's t-testing.

RESULTS: Recruitment included 65 normotensive controls, 34 women with chronic hypertension (CH), 51 with gestational hypertension (GH), and 21 with PE. Significantly higher weight, body surface area, and blood pressure measurements were found in the hypertensive, compared with the normotensive control and pregnancies. There were no observed differences in USCOM-measured CO, cardiac index, SVR, or systemic vascular resistance index between hypertensive women who did versus did not develop PE or severe PE in later pregnancy. Analysis of the CH and GH subgroups, as well as only unmedicated hypertensive women ( n  = 24), also showed no significant difference in hemodynamic parameters between those who did or did not develop PE or severe PE.

CONCLUSIONS: Our group was unable to successfully predict the onset of PE or severe PE based on hemodynamic parameters measured with the USCOM. It is possible this relates to the high proportion of women on antihypertensive medication at recruitment.