SUBLINGUAL MICROCIRCULATION OF PREGNANT AND NON-PREGNANT WOMEN
Abstract Number: S-27
Abstract Type: Original Research
Introduction: Microcirculation, the small vessels in the vasculature, embedded within organs, is responsible for the distribution of blood within tissues, regulation of blood pressure, delivery of oxygen and other nutrients. Sidestream Dark-Field (SDF) imaging is a stroboscopic imaging modality, allowing assessment of microcirculation. Blood flow is quantified using Microvascular Flow Index (MFI), perfused vessel density (PVD), and the proportion of perfused vessels (PPV). The objectives were to compare the sublingual microcirculation of pregnant subjects to that of comparable non-pregnant volunteers. Methodology: The primary outcome is the difference between the MFI of pregnant versus non-pregnant subjects. Inclusion criteria include ASA I-II participants in two groups; Pregnant – non-labouring women with singleton pregnancies, at term gestation, Non-Pregnant – healthy female volunteers, matched to pregnant participants for age ± 1 year. Participants were excluded with hypertensive and other cardiovascular disease, obesity, diabetes, or caffeine intake within 2 hours. The SDF device was be applied to the sublingual mucosal surface obtaining steady images of at least 20 seconds duration. Each participant was be asked to provide 20 second measurements in five visual fields. Data Analysis: Video clips were analysed blindly and at random to prevent coupling between images. The mean MFI values for each individual was analyzed using paired t-test. Apriori power calculation was performed for the difference between two independent means; effect size 1.125, alpha 0.05, power 0.8. Fourteen subjects per group results in 82% power. To address our assumptions and potential drop-outs we will increase the group size by 20%. Results: Thirty-seven participants were recruited (19 pregnant, 18 non-pregnant), a single pregnant participant was withdrawn because of technical issues. Morphometric characteristics are listed in table 1. The PVD and PPV were not significantly different, while the MFI was significantly higher in the pregnant group. Conclusion: The microvascular flow index of pregnant women is higher than a comparable non-pregnant group, which appears to correlate the physiological changes of pregnant women. Future projects of this novel imaging technique should focus on determining the time course of these changes and the impact of disease process, i.e. preeclampsia and gestational diabetes on the microvascular and ultimately on the maternal-fetal unit.