Delemarre F M, van Leest L A, Jongsma H W, Steegers E A
Department of Obstetrics and Gynecology, University Hospital, St. Radboud Nijmegen, The Netherlands.
J Matern Fetal Med. 2000 Jul-Aug;9(4):197-200. doi: 10.1002/1520-6661(200007/08)9:4<197::AID-MFM1>3.0.CO;2-0.
To study the influence of chronic dietary sodium restriction on uteroplacental circulation.
In a randomized trial, Doppler flow velocity waveforms of the uterine and umbilical artery were studied at monthly intervals during pregnancy in 59 women on a low-sodium diet and in 68 controls.
Pulsatility index (PI), resistance index (RI), and A/B ratio of the uterine artery were significantly lower during sodium restriction, whereas PI, RI, and A/B ratio of the umbilical artery were significantly higher.
The lower resistance indices of the uterine artery during sodium restriction might reflect an increase in pulse pressure/impedance ratio as a result of activation of the renin-angiotensin system. The increase in umbilical artery resistance indices supports the hypothesis that fetal circulation might be altered by chronic dietary sodium restriction.