Original Articles
Long-term clinical outcome of infants with mild and moderate fetal pyelectasis: validation of neonatal ultrasound as a screening tool to detect significant nephrouropathies

https://doi.org/10.1016/j.jpeds.2004.02.035Get rights and content

Abstract

Objective

To assess the long-term outcome of infants with mild and moderate fetal pyelectasis and to determine the predictive value of neonatal ultrasound imaging in identifying significant nephrouropathies.

Study design

This prospective study included 213 infants with antenatal mild to moderate pyelectasis who were followed for up to 2 years. Postnatal renal ultrasound examinations were performed at day 5 and months 1, 3, 6, 12 and 24 after birth. Voiding cystourethrography was performed in all infants.

Results

Normal or nonsignificant findings were diagnosed in 130 of 213 (61%) infants. Significant nephrouropathies were diagnosed in 83 of 213 (39%) infants. The sensitivity, specificity, positive predictive value, and negative predictive value of two successive neonatal renal ultrasound examinations performed at day 5 and 1 month to predict significant nephrouropathies were 96%, 76%, 72%, and 97%, respectively. In 102 of 213 (48%) infants with normal neonatal renal ultrasound scans, we later found only three of 102 (3%) cases with significant nephrouropathies.

Conclusions

We found in a population of infants with mild to moderate fetal pyelectasis a 39% incidence of significant nephrouropathies. Ultrasound is an excellent screening tool with high sensitivity and negative predictive value that allows avoidance of unjustified medical follow-up in patients with two normal neonatal ultrasound scans.

Section snippets

Methods

As part of a prospective study evaluating the results of systematic VCUG in infants with antenatally diagnosed renal pelvis dilatation,10 we documented the clinical and imaging evolution of these children during 2 years of follow-up. This prospective cohort study was conducted in two hospitals in Brussels (without bias in referral pattern). Prenatal ultrasound was performed once every trimester as part of a routine evaluation of pregnancy in an unselected population. All routine antenatal

Results

From October 1998 through October 2000, a prenatal diagnosis of mild to moderate renal pelvis dilatation was made in 258 of 5643 fetuses. Forty-five cases (17%) were excluded from the study because of incomplete postnatal data. The remaining 213 newborns (139 boys and 74 girls; male to female ratio, 1.88:1) were scheduled for investigation following the above protocol, and were followed prospectively for up to 2 years in our department of perinatal nephrology.

Discussion

For 20 years, obstetric ultrasound has been performed routinely during pregnancies in Europe. In Belgium, three sonographic examinations are performed, one in each trimester. This has led to the discovery of many fetal anomalies, and among them, upper renal tract dilatation represents one of the largest groups amenable to neonatal management.12

The current study highlights the importance of following up all cases of antenatal mild to moderate renal pelvis dilatation. Our results show that mild

References (14)

There are more references available in the full text version of this article.

Cited by (111)

  • Pediatric Nephro-Urology: Overview and Updates in Diuretic Renal Scans and Renal Cortical Scintigraphy

    2022, Seminars in Nuclear Medicine
    Citation Excerpt :

    Dilatation of the pelvicalyceal system with or without dilatation of the ureter can suggest underlying obstruction but frequently occurs without any physical obstruction to urine flow. Ureteropelvic junction stenosis occurs in 13% of antenatally diagnosed hydronephrosis4 Vesicoureteral reflux resolved intrauterine obstructions and flaccidity of the pelvis and ureter are common reasons for non-obstructive dilatation of the urinary tract5 Ultrasonography (US) is an excellent tool for pre and post-natal detection of hydronephrosis and hydroureteronephrosis, for monitoring spontaneous changes in the degree of dilatations overtime and for evaluation of surgical interventions.

  • Renal development in the fetus and premature infant

    2017, Seminars in Fetal and Neonatal Medicine
  • Frequency of postnatal hydronephrosis in infants with a renal anterior-posterior pelvic diameter > 4 mm on midtrimester ultrasound

    2015, Taiwanese Journal of Obstetrics and Gynecology
    Citation Excerpt :

    There is no clear consensus on the follow up and management of mild or moderate hydronephrosis observed on antenatal ultrasound, although it is generally recommended that a postnatal evaluation be performed if the AP diameter of the renal pelvis exceeds 10 mm at any point in gestation [13]. Although a number of predictive algorithms have been developed, some studies have indicated that mild hydronephrosis that resolves during the course of a pregnancy may reoccur and progress, ultimately requiring treatment [14–16]. Thus, determining the occurrence of postnatal hydronephrosis based on the presence of antenatal renal pelvic dilatation may aid in identifying neonates in which an evaluation for causes of hydronephrosis is warranted.

View all citing articles on Scopus

Presented in part at the 12th Congress of the International Pediatric Nephrology Association, September 1-5, 2001, Seattle, Washington.

The members of the Brussels Free University Perinatal Nephrology Study Group are listed in the Appendix.

View full text