Women in late pregnancy experience an increase in collateral venous blood flow when lying supine, likely as a response to marked compression of the IVC in this position. However, cardiac output and aortic blood flow were found to decrease while in the supine position.

Introduction: Supine positioning during late pregnancy causes the gravid uterus to compress the inferior vena cava, resulting in dramatic hemodynamic changes. The maintenance of placental perfusion requires maternal circulatory and autonomic adaptations. Women with supine hypotensive syndrome (defined as a drop in systolic blood pressure of anything between 15 and 30 mmHg or an increase in heart rate of 20 bpm, with or without symptoms) may have reduced ability to compensate for the effects of supine positioning. Anna-Maria Lydon and all the staff and technicians employed at The Center for Advanced MRI for their expertise in developing the MRI protocol, carrying out the MRI scans and assisting with data analysis.

Recent literature has reported an association between maternal supine sleep position and stillbirth during late pregnancy. In this position the gravid uterus almost completely obstructs the inferior vena cava. A small number of women experience supine hypotension, thought to be due in part to inadequate collateral venous circulation. The aim of this paper is to review the literature describing the anatomy of the collateral venous system and in particular the azygos system, the abdominal portion of which has not been well studied. A systematic review was conducted using the electronic databases: Medline, Embase, Scopus, and Google Scholar. Relevant anatomical and radiological literature concerning the azygos system in particular was reviewed. The search was limited to adult human studies only. The collateral venous system can be divided into superficial, intermediate and deep systems. The azygos system in particular provides immediate collateral venous circulation in the event of acute inferior vena caval obstruction. The abdominal portion of this pathway, including the ascending lumbar vein, has not been well studied and there are certain variations that can render it ineffective. In conclusion, the collateral venous system provides an alternative route for blood to flow back to the systemic circulation when acute occlusion of the inferior vena cava occurs in the supine position during late pregnancy. However, certain anatomical variations can render this pathway ineffective, and this could have implications for the development of supine hypotension and stillbirth in late pregnancy. Clin. Anat. 30:1087-1095, 2017. © 2017 Wiley Periodicals, Inc.

IntroductionSupine positioning during late pregnancy causes dramatic compression of maternal abdominal vasculature and is a risk factor for stillbirth. The azygos vein has been shown to provide collateral circulation in this scenario. There are many well‐known anatomical differences in abdominal vasculature between the left and right sides of the body. However, the effect of left and right positioning in pregnancy has not been well studied.Materials and MethodsAfter obtaining ethics approval, 10 women with uncomplicated pregnancies between 34 and 38 weeks gestation underwent magnetic resonance imaging in the left and right lateral positions. Phase contrast images were evaluated to measure blood flow through the abdominal aorta, inferior vena cava, and azygos vein.ResultsNo significant differences between left and right lateral positions were found in blood flow through the IVC at its formation (mean difference −0.15 L/min [CI −0.47, 0.18], p = .34) or through the azygos vein (mean difference 0.02 L/min [CI −0.22, 0.26], p = .87). Blood flow through the IVC just above the level of the renal veins was found to be reduced by 35% in the right lateral position when compared to the left (mean difference 1.01 L/min [CI 0.25, 1.43], p = .03). There were no significant differences in cardiac output or blood flow through the abdominal aorta.ConclusionsWhile it was noted that blood flow through the IVC immediately above the level of the renal veins was reduced in the right lateral position, this did not appear to impact significantly on maternal cardiac output or blood flow through the azygos vein.

Background Patients attending general medicine outpatient clinics (GM OPC) at hospital face multiple healthcare demands in an environment that has evolved with the clinician at its centre. The ideas, knowledge and understanding that patients bring to their clinic appointments are not well studied in the New Zealand setting. Aims To assess how hospitals prepare patients for their outpatient appointments and encourage people to participate actively in their own care. Methods A prospective survey of 50 patients attending follow‐up GM OPC was performed. Participants’ understanding of the purpose of their appointment and knowledge of their prescription medications was explored using a nine‐item questionnaire. Patient‐directed hospital communication was then analysed to assess the information supplied to patients. Results Two‐thirds (66%) of participants attending follow‐up GM OPC recalled being informed of an appointment at the time of leaving hospital; only half (54%) felt they had been informed of the purpose of these appointments. Patient‐directed communication was not completed in half (50%) of the analysed discharge letters. One‐third (36%) of participants did not have specific questions for their clinic visits. Conclusions Limited information and support is provided to patients attending follow‐up GM OPC and is not tailored to individuals’ health literacy. This practice assumes patients have comparable health literacy to clinicians, which may have downstream impacts on the usefulness of the clinic experience. The information that health users bring to clinic may be improved by increasing pre‐clinic user engagement and deploying patient‐centred tools within the healthcare environment.