Fetal blood flow in the renal artery during the third pregnancy trimester

: Blood flow velocity waveforms of the renal artery were examined in 112 cases between the 28th and 40th weeks of pregnancy. The measurements were performed with Hitachi EUB 450 pulsed Doppler ultrasound system. For evaluation of the blood flow velocity waveforms of the renal artery resistence index was calculated. If the other examined vessels (umbilical artery, medial cerebral artery), and the following CT examination pathological sign were not found, the renal artery blood flow was considered as a normal value. The results showed that in normal cases the renal artery resistence index decreased moderately during the third trimester of pregnancy. This decreasing tendency might caused by the increased blood flow of the renal circulation.