An MRI assessment of inferior vena cava vessel morphology and venous flow in chronic hypertensive and normotensive pregnant women in the supine position.

The supine position in pregnancy may develop supine hypertensive syndrome (SHS) caused by the gravid uterus compressing the inferior vena cava (IVC) and compromising venous return. The effect of positioning on vessel morphology and venous return in chronic hypertensive pregnant women has not been assessed. We used phase contrast imaging to assess matched groups of chronic hypertensive and normotensive women in the supine position. There were no significant differences in IVC morphology or venous return between the two groups, supporting the conclusion that chronic hypertensive women are not at higher risk than normotensives when supine.