Effects of maternal prone position on the umbilical arterial flow.
OBJECTIVE
The objective of our study was to clarify the effect of the maternal prone position on the feto-placental flow. In this position, the uterine compression of the large maternal vessels was expected to be completely eliminated.


METHODS
Twenty-three normal pregnant women were cross-sectionally examined in the supine, the left lateral, the right lateral and the prone position. The systolic/diastolic ratios for the umbilical artery were calculated for each position.


RESULTS
The umbilical arterial systolic/diastolic ratio in the prone position significantly decreased compared with that in the supine position. The left and right lateral position showed no significant change in the systolic/diastolic ratio.


CONCLUSIONS
The maternal prone position can provide complete relief of uterine compression of the large maternal vessels.
Nakai
Y
Y
Department of Obstetrics and Gynaecology, School of Medicine, Osaka City University, Osaka, Japan.
Mine
M
M
Nishio
J
J
Maeda
T
T
Imanaka
M
M
Ogita
S
S
D003430:Cross-Sectional Studies; D003971:Diastole; D005260:Female; D006801:Humans; D011247:Pregnancy; D016684:Prone Position; D012039:Regional Blood Flow; D013599:Systole; D014469:Umbilical Arteries / Q000502:physiology*