The accuracy of antenatal ultrasonography in identifying renal abnormalities
C. E. Johnson, J. S. Elder, N. E. Judge, F. N. Adeeb, E. R. Grisoni and D. C. Fattlar
Department of Pediatrics, Case Western Reserve School of Medicine, Cleveland, Ohio.
OBJECTIVE--To determine the accuracy of measuring antenatal renal pelvic
diameter for prediction of renal abnormalities. RESEARCH
DESIGN--Prospective evaluation of all pregnant women undergoing
ultrasonography. SETTING--A teaching hospital providing primary and
referral maternity care. PARTICIPANTS--Fifty-six pregnant women with
suspected fetal hydronephrosis or cystic lesions identified from 7500
ultrasonograms over 3 years. METHODS--Antenatal renal pelvic diameter was
measured in the anteroposterior dimension. Neonates underwent postnatal
ultrasonography after day 3 of life; if the results were abnormal, a
cystogram and renal diuretic scan were obtained. RESULTS--None of 50
kidneys 15 mm or smaller in anteroposterior pelvic diameter had
obstruction; 11 (79%) of 14 kidneys larger than 15 mm were obstructed or
demonstrated vesicoureteral reflux. Of 12 kidneys believed to be
multicystic before birth, five (42%) proved to have hydronephrosis.
CONCLUSIONS--Since the majority of fetuses with suspected hydronephrosis
proved to be normal, parents should not be unduly alarmed by the physician.
Renal pelvic diameter of more than 15 mm is strongly predictive of
hydronephrosis. Since severe hydronephrosis is treatable and can be
mistaken for a multicystic kidney antenatally, full radiologic evaluation
is needed soon after birth.
