[The renal arterial pedicle in the human fetus]

To analyze the incidence of renal arteries variations during the fetal period and compare these findings with previous findings in adults, we studied the renal arterial pedicle in 70 human fetuses ranging in age from 13 to 36 weeks postconception. The fetuses were injected through the right common carotid artery with a red polyester resin to fill in the arterial tree enabling the identification and dissection of the small fetal arteries. The renal arteries were analyzed considering their number, origin, direction and site of penetration. Among the 70 fetuses studied, 30 (42.8%) presented at least one kidney with renal artery variations. In 6 fetuses the variation was bilateral. Among the total of 140 renal pedicles studied, 36 presented arterial variations (25.7%). We did not find statistically significant difference between right and left kidneys and between male and female fetuses. In the present study we did find kidneys with more than 2 arteries, probably because we did not study kidneys with any kind of development anomaly. Even kidneys with malrotations of the vertical axis were removed from the study.