Antenatal renal pelvis dilatation emphasizing vesicoureteric reflux: two-year follow-up of minor postnatal dilatation.

AIM: To describe the occurrence of foetal renal pelvis dilatation in an unselected population of pregnancies and to describe the clinical course in a subgroup of infants with minor renal pelvis dilatation (RPD).

METHODS

During 1996-1999 the foetuses of 17850 consecutive pregnant women were scanned with ultrasonography (USG) in the 16th-19th gestational week and later in the pregnancy when indicated. RPD was defined as anterior-posterior pelvic diameter > or = 5 mm. After birth all infants were examined with USG twice. If any postnatal USG showed RPD > or = 10 mm, extended radiological investigation was performed. Infants with pelvis dilatation < 10 mm and no calyceal or ureteric dilatation were not investigated further and antibiotic prophylaxis was discontinued. The children were followed up at 2 y of age.

RESULTS

109 foetuses (0.6%) with RPD were identified. Postnatally, 94/109 were available for follow-up: 43 had postnatal dilatation > or = 10 mm and were investigated and treated according to clinical routine, while 51 had dilatation < 10 mm and were followed up after they had reached at least 2 y of age. No case of pyelonephritis was recorded. USG in 48/51 children was normal.

CONCLUSION

The data indicate that infants with minor RPD do not constitute a risk group for renal morbidity and thus do not need antibiotic prophylaxis and extensive radiological examination.