[Natural history of fetal pyelocaliectasia]

It is estimated that genitourinary anomalies comprise 20% of all antenatally detected fetal anomalies, and pyelocaliectasia is the most common one. Detection of antenatal dilatation of the urinary tract does not always indicate postnatal urinary tract obstruction or even a significant genitourinary anomaly. Most cases will improve spontaneously, representing a temporary physiologic impedence and do not require surgery.

In a two-year period we studied 197 newborns, with prenatal pyelocaliectasia, without concomitant anomaly, delivered at Maternidade Dr. Daniel de Matos. In the postnatal follow-up period, the infants were followed at Pediatrics Department, at our Center.

A male predilection was found. Ultrasonic follow-up of the 197 infants showed that pyelocaliectasia resolved in 97%, while 3% still presented it in the postnatal ultrasound. Complementary renal evaluation, with voiding cystourethrography and radionuclide imaging, was realised in 29 (15%) infants to further characterize the abnormality detected in postnatal ultrasound. Surgery was performed in four (2%) children.

Prenatally diagnosed pyelocaliectasia may be safely observed, and surgical correction should be performed only if renal compromise occurs.