Overview of fetal hydronephrosis
- Laurence S Baskin, MD, FAAP
Laurence S Baskin, MD, FAAP
- Section Editor — Pediatric Urology
- Frank Hinman, Jr, MD, Distinguished Professorship in Pediatric Urology
- Chief Pediatric Urology
- Professor of Urology and Pediatrics
- UCSF Benioff Children's Hospital
- Section Editors
- Tej K Mattoo, MD, DCH, FRCP
Tej K Mattoo, MD, DCH, FRCP
- Section Editor — Pediatric Nephrology
- Professor of Pediatrics
- Wayne State University School of Medicine
- Louise Wilkins-Haug, MD, PhD
Louise Wilkins-Haug, MD, PhD
- Section Editor — Prenatal Diagnosis and Genetics
- Professor of Obstetrics, Gynecology, and Reproductive Biology
- Harvard Medical School
- Duncan Wilcox, MD
Duncan Wilcox, MD
- Section Editor — Pediatric Urology
- Professor of Urology, The Ponzio Family Chair in Pediatric Urology
- University of Colorado
Fetal hydronephrosis (dilation of the renal pelvis with or without dilation of the renal calyces) is a common finding on antenatal ultrasound [1,2]. In most cases, renal pelvic dilation is a transient physiologic state, however, congenital anomalies of the kidney and urinary tract (CAKUT) can present with fetal hydronephrosis due to urinary tract obstruction and vesicoureteral reflux (VUR). These conditions may be associated with impaired renal development and/or cause renal injury.
Nevertheless, the majority of cases of fetal hydronephrosis are not clinically significant, and therefore excessive concern may lead to unnecessary testing of the newborn infant and anxiety for parents and health care providers. The goal of prenatal management is to detect those cases of fetal hydronephrosis that may adversely affect the health of the infant and require antenatal and postnatal evaluation, timely referral to a pediatric urologist if required, and possible intervention to minimize adverse outcomes, while limiting testing in those cases that are due to a benign, transient condition.
The definition, etiology, and management of fetal hydronephrosis are reviewed here. Postnatal evaluation of fetal hydronephrosis and specific urologic conditions that may present as fetal hydronephrosis are discussed separately. (See "Postnatal management of fetal hydronephrosis" and "Congenital ureteropelvic junction obstruction" and "Primary megaureter in infants and children" and "Ectopic ureter" and "Clinical presentation and diagnosis of posterior urethral valves", section on 'Prenatal' and "Clinical presentation, diagnosis, and course of primary vesicoureteral reflux".)
DEFINITION AND GRADING
Several systems have been developed to diagnose and grade the severity of fetal hydronephrosis . There is no consensus on the most appropriate grading criteria for the diagnosis of fetal hydronephrosis . In general, the likelihood of having a significant renal anomaly correlates with the severity of hydronephrosis.
Scoring systems differ based upon the fetal ultrasound criteria used and include:To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:
- Blyth B, Snyder HM, Duckett JW. Antenatal diagnosis and subsequent management of hydronephrosis. J Urol 1993; 149:693.
- Robyr R, Benachi A, Daikha-Dahmane F, et al. Correlation between ultrasound and anatomical findings in fetuses with lower urinary tract obstruction in the first half of pregnancy. Ultrasound Obstet Gynecol 2005; 25:478.
- Sidhu G, Beyene J, Rosenblum ND. Outcome of isolated antenatal hydronephrosis: a systematic review and meta-analysis. Pediatr Nephrol 2006; 21:218.
- Zanetta VC, Rosman BM, Bromley B, et al. Variations in management of mild prenatal hydronephrosis among maternal-fetal medicine obstetricians, and pediatric urologists and radiologists. J Urol 2012; 188:1935.
- Woodward M, Frank D. Postnatal management of antenatal hydronephrosis. BJU Int 2002; 89:149.
- Nguyen HT, Herndon CD, Cooper C, et al. The Society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis. J Pediatr Urol 2010; 6:212.
- Chitty LS, Altman DG. Charts of fetal size: kidney and renal pelvis measurements. Prenat Diagn 2003; 23:891.
- Scott JE, Wright B, Wilson G, et al. Measuring the fetal kidney with ultrasonography. Br J Urol 1995; 76:769.
- Odibo AO, Marchiano D, Quinones JN, et al. Mild pyelectasis: evaluating the relationship between gestational age and renal pelvic anterior-posterior diameter. Prenat Diagn 2003; 23:824.
- Robinson JN, Tice K, Kolm P, Abuhamad AZ. Effect of maternal hydration on fetal renal pyelectasis. Obstet Gynecol 1998; 92:137.
- Graif M, Kessler A, Hart S, et al. Renal pyelectasis in pregnancy: correlative evaluation of fetal and maternal collecting systems. Am J Obstet Gynecol 1992; 167:1304.
- Leung VY, Chu WC, Metreweli C. Hydronephrosis index: a better physiological reference in antenatal ultrasound for assessment of fetal hydronephrosis. J Pediatr 2009; 154:116.
- Blachar A, Blachar Y, Livne PM, et al. Clinical outcome and follow-up of prenatal hydronephrosis. Pediatr Nephrol 1994; 8:30.
- Pates JA, Dashe JS. Prenatal diagnosis and management of hydronephrosis. Early Hum Dev 2006; 82:3.
- Ismaili K, Hall M, Donner C, et al. Results of systematic screening for minor degrees of fetal renal pelvis dilatation in an unselected population. Am J Obstet Gynecol 2003; 188:242.
- Lee RS, Cendron M, Kinnamon DD, Nguyen HT. Antenatal hydronephrosis as a predictor of postnatal outcome: a meta-analysis. Pediatrics 2006; 118:586.
- Grignon A, Filion R, Filiatrault D, et al. Urinary tract dilatation in utero: classification and clinical applications. Radiology 1986; 160:645.
- Corteville JE, Gray DL, Crane JP. Congenital hydronephrosis: correlation of fetal ultrasonographic findings with infant outcome. Am J Obstet Gynecol 1991; 165:384.
- Scalabre A, Demède D, Gaillard S, et al. Prognostic Value of Ultrasound Grading Systems in Prenatally Diagnosed Unilateral Urinary Tract Dilatation. J Urol 2016.
- Fernbach SK, Maizels M, Conway JJ. Ultrasound grading of hydronephrosis: introduction to the system used by the Society for Fetal Urology. Pediatr Radiol 1993; 23:478.
- Nguyen HT, Benson CB, Bromley B, et al. Multidisciplinary consensus on the classification of prenatal and postnatal urinary tract dilation (UTD classification system). J Pediatr Urol 2014; 10:982.
- González R, Schimke CM. Ureteropelvic junction obstruction in infants and children. Pediatr Clin North Am 2001; 48:1505.
- Dudley JA, Haworth JM, McGraw ME, et al. Clinical relevance and implications of antenatal hydronephrosis. Arch Dis Child Fetal Neonatal Ed 1997; 76:F31.
- Livera LN, Brookfield DS, Egginton JA, Hawnaur JM. Antenatal ultrasonography to detect fetal renal abnormalities: a prospective screening programme. BMJ 1989; 298:1421.
- Persutte WH, Koyle M, Lenke RR, et al. Mild pyelectasis ascertained with prenatal ultrasonography is pediatrically significant. Ultrasound Obstet Gynecol 1997; 10:12.
- Havutcu AE, Nikolopoulos G, Adinkra P, Lamont RF. The association between fetal pyelectasis on second trimester ultrasound scan and aneuploidy among 25,586 low risk unselected women. Prenat Diagn 2002; 22:1201.
- van Eerde AM, Meutgeert MH, de Jong TP, Giltay JC. Vesico-ureteral reflux in children with prenatally detected hydronephrosis: a systematic review. Ultrasound Obstet Gynecol 2007; 29:463.
- Dias CS, Bouzada MC, Pereira AK, et al. Predictive factors for vesicoureteral reflux and prenatally diagnosed renal pelvic dilatation. J Urol 2009; 182:2440.
- Andrés-Jensen L, Jørgensen FS, Thorup J, et al. The outcome of antenatal ultrasound diagnosed anomalies of the kidney and urinary tract in a large Danish birth cohort. Arch Dis Child 2016; 101:819.
- Duncan KA. Antenatal renal pelvic dilatation; the long-term outlook. Clin Radiol 2007; 62:134.
- Barbosa JA, Chow JS, Benson CB, et al. Postnatal longitudinal evaluation of children diagnosed with prenatal hydronephrosis: insights in natural history and referral pattern. Prenat Diagn 2012; 32:1242.
- Anderson N, Clautice-Engle T, Allan R, et al. Detection of obstructive uropathy in the fetus: predictive value of sonographic measurements of renal pelvic diameter at various gestational ages. AJR Am J Roentgenol 1995; 164:719.
- Fugelseth D, Lindemann R, Sande HA, et al. Prenatal diagnosis of urinary tract anomalies. The value of two ultrasound examinations. Acta Obstet Gynecol Scand 1994; 73:290.
- Aviram R, Pomeranz A, Sharony R, et al. The increase of renal pelvis dilatation in the fetus and its significance. Ultrasound Obstet Gynecol 2000; 16:60.
- Siemens DR, Prouse KA, MacNeily AE, Sauerbrei EE. Antenatal hydronephrosis: thresholds of renal pelvic diameter to predict insignificant postnatal pelviectasis. Tech Urol 1998; 4:198.
- Cohen-Overbeek TE, Wijngaard-Boom P, Ursem NT, et al. Mild renal pyelectasis in the second trimester: determination of cut-off levels for postnatal referral. Ultrasound Obstet Gynecol 2005; 25:378.
- Bassanese G, Travan L, D'Ottavio G, et al. Prenatal anteroposterior pelvic diameter cutoffs for postnatal referral for isolated pyelectasis and hydronephrosis: more is not always better. J Urol 2013; 190:1858.
- Signorelli M, Cerri V, Taddei F, et al. Prenatal diagnosis and management of mild fetal pyelectasis: implications for neonatal outcome and follow-up. Eur J Obstet Gynecol Reprod Biol 2005; 118:154.
- Coco C, Jeanty P. Isolated fetal pyelectasis and chromosomal abnormalities. Am J Obstet Gynecol 2005; 193:732.
- Corteville JE, Dicke JM, Crane JP. Fetal pyelectasis and Down syndrome: is genetic amniocentesis warranted? Obstet Gynecol 1992; 79:770.
- Persutte WH, Hussey M, Chyu J, Hobbins JC. Striking findings concerning the variability in the measurement of the fetal renal collecting system. Ultrasound Obstet Gynecol 2000; 15:186.
- The fetal genitourinary tract. In: Ultrasonography in Obstetrics and Gynecology, 5th ed, Callen PW (Ed), Saunders, Philadelphia 2007. p.647.
- Maizels M, Alpert SA, Houston JT, et al. Fetal bladder sagittal length: a simple monitor to assess normal and enlarged fetal bladder size, and forecast clinical outcome. J Urol 2004; 172:1995.
- Gorincour G, Rypens F, Toiviainen-Salo S, et al. Fetal urinoma: two new cases and a review of the literature. Ultrasound Obstet Gynecol 2006; 28:848.
- Limwongse C, Cassidy SB. Syndromes and malformations of the urinary tract. In: Pediatric Neprhology, 5th, Avner ED, Harmon WE, Niaudet P (Eds), Lippincott Williams and Wilkins, Philadelphia 2004. p.93.
- Damen-Elias HA, De Jong TP, Stigter RH, et al. Congenital renal tract anomalies: outcome and follow-up of 402 cases detected antenatally between 1986 and 2001. Ultrasound Obstet Gynecol 2005; 25:134.
- Harrison MR, Golbus MS, Filly RA, et al. Fetal hydronephrosis: selection and surgical repair. J Pediatr Surg 1987; 22:556.
- Nassr AA, Shazly SA, Abdelmagied AM, et al. Effectiveness of vesico-amniotic shunt in fetuses with congenital lower urinary tract obstruction: An updated systematic review and meta-analysis. Ultrasound Obstet Gynecol 2016.
- Coplen DE. Prenatal intervention for hydronephrosis. J Urol 1997; 157:2270.
- Crombleholme TM, Harrison MR, Golbus MS, et al. Fetal intervention in obstructive uropathy: prognostic indicators and efficacy of intervention. Am J Obstet Gynecol 1990; 162:1239.
- Holmes N, Harrison MR, Baskin LS. Fetal surgery for posterior urethral valves: long-term postnatal outcomes. Pediatrics 2001; 108:E7.
- Morris RK, Malin GL, Khan KS, Kilby MD. Systematic review of the effectiveness of antenatal intervention for the treatment of congenital lower urinary tract obstruction. BJOG 2010; 117:382.
- Morris RK, Ruano R, Kilby MD. Effectiveness of fetal cystoscopy as a diagnostic and therapeutic intervention for lower urinary tract obstruction: a systematic review. Ultrasound Obstet Gynecol 2011; 37:629.
- Ruano R, Sananes N, Sangi-Haghpeykar H, et al. Fetal intervention for severe lower urinary tract obstruction: a multicenter case-control study comparing fetal cystoscopy with vesicoamniotic shunting. Ultrasound Obstet Gynecol 2015; 45:452.
- Aulbert W, Kemper MJ. Severe antenatally diagnosed renal disorders: background, prognosis and practical approach. Pediatr Nephrol 2016; 31:563.
- Morris RK, Malin GL, Quinlan-Jones E, et al. Percutaneous vesicoamniotic shunting versus conservative management for fetal lower urinary tract obstruction (PLUTO): a randomised trial. Lancet 2013; 382:1496.
- DEFINITION AND GRADING
- Renal pelvic diameter (RPD)
- Society of Fetal Urology (SFU)
- Urinary tract dilation (UTD) classification system
- Transient hydronephrosis
- Congenital anomalies of the kidney and urinary tract (CAKUT)
- - Severity of hydronephrosis
- - Timing and repeat ultrasound testing
- Down syndrome
- ULTRASOUND EXAMINATION
- Renal and urologic examination
- Other anomalies
- - Further evaluation
- Fetal surgery
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS