The effect of positioning on maternal anatomy and hemodynamics during late pregnancy

Abstract

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.

Renal Tumors in Pregnancy: A Case Report Focusing on the Timing of the Surgery and Patient Positioning

“…A recent study on ten pregnant women showed a 35% lower venous return in RRLP than RLLP; however, this difference in cardiac output and blood flow of the abdominal aorta (and thus the placental perfusion) is insignificant between left and right lateral decubitus positions [ 14 ]. Fujita et al analyzed thirteen pregnant women and concluded that IVC volume is most at a 30-degree tilt to the left and right in 70% and 23% of patients, respectively [ 10 ].…”

Aggressive giant cell tumour (GCT) of the distal humerus in a young pregnant woman

“…Positioning of the patient was another concern since the prone position could not be used due to pregnancy, and the right lateral position was chosen. The latter is associated with its drawbacks due to compression of the inferior vena cava, leading to reduced venous return and the risk of thromboembolism 14. The use of general anaesthesia reduces the risk of preterm labour and hence was preferred in this case.…”

Effects of Stress and Anxiety on Pregnant Women's Cardiovascular Health: A Narrative Review

“…In these cases, the patient presents transient tachycardia and late bradycardia, pallor, diaphoresis, sweating, nausea, hypotension, and dizziness in the supine position, which improves if the patient turns to the side position. This phenomenon can lead to the loss of consciousness or even sudden death of the pregnant woman in its severe form [26].…”