Hemodynamic Comparison of Inferior Vena Cava Collapsibility Index in Patients with Preeclampsia vs. Controls: A Pilot Study

Background/Objectives: There is a paucity of research studying point-of-care ultrasound in the pregnant population, despite the rising incidence of maternal medical complications and, in particular, preeclampsia. This study sought to compare the inferior vena cava collapsibility index (IVC-CI) between patients with preeclampsia with severe features (PECS) and gestational age-matched controls and to assess whether pulse pressure (PP) correlates with IVC-CI in PECS. Methods: This was a prospective pilot study of patients recruited at an inpatient hospital and an outpatient office. The case group included admitted patients with a diagnosis of PECS considered to be stable for prolonged antepartum expectant management. One patient per gestational age week from 23 to 34 weeks with PECS was compared to a gestational age-matched patient without any form of preeclampsia and/or gestational hypertension. Patients on magnesium sulfate, those with multiple gestation, large-for-gestational age fetus, fetal growth restriction, polyhydramnios, oligohydramnios, and/or an anomalous fetus were excluded. Results: IVC-CI was significantly lower in the PECS group compared with controls (mean 20.1% vs. 48.3%, 95% CI = −0.40–−0.16, <i>p</i> < 0.001). There was an inverse relationship between IVC-CI and pulse pressure in patients with PECS. For each additional 1 mmHg in pulse pressure, the odds of having IVC-CI greater than 50% decreased by 13%. Conclusions: Patients with preeclampsia exhibit detectable changes in inferior vena cava diameter that can be assessed with bedside ultrasound and correlated with maternal PP. Future research should focus on validating these findings and exploring the clinical significance of these measurements.