Journal of Ultrasound in Medicine, Vol 4, Issue 2 85-89, Copyright © 1985 by American Institute of Ultrasound in Medicine
Minimal fetal renal pyelectasis
W. K. Hoddick, R. A. Filly, B. S. Mahony and P. W. Callen
To assess the possible relationship between the degree of maternal
hydration and the sonographic identification of minimal fetal renal
pyelectasis, a prospective study was performed in which fetuses
demonstrating mild dilation of the renal pelvis (maximum diameter ranging
from 3 to 11 mm) were reexamined after the mothers refrained from oral
intake for 12 hours. Complete or almost complete resolution of the
pyelectasis occurred in only four of 17 kidneys (23.5 per cent) while the
remaining fetal kidneys demonstrated little or no change in the degree of
pyelectasis following maternal dehydration. This observation, as well as
previous experimental research, suggests that the state of maternal oral
hydration is not a major cause of minimal fetal pyelectasis. Additionally,
the observation of fetal pyelectasis measuring at least 3 mm in greatest
dimension is common, occurring in approximately 18 per cent of fetuses
older than 24 menstrual weeks.