Increased kidney length in mild urinary tract dilatation is a significant prognostic factor for non-resolution

Increased kidney length in mild urinary tract dilatation is a significant prognostic factor for non-resolution | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Increased kidney length in mild urinary tract dilatation is a significant prognostic factor for non-resolution Shingo Ishimori, Junya Fujimura, Atsushi Nishiyama, Takeshi Morisawa This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5319229/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Mar, 2025 Read the published version in Pediatric Nephrology → Version 1 posted 5 You are reading this latest preprint version Abstract Purpose Even asymptomatic and mild urinary tract dilatation (UTD) that does not resolve may harbor the potential for progression of the severity of UTD, which suggests the need for continued observation. However, no studies have investigated factors contributing to the persistence or non-resolution of mild UTD. Materials and Methods We conducted a prospective cohort study of children who were newly diagnosed with mild UTD during the neonatal period from 2013 to 2021. They were evaluated by periodic kidney ultrasound until 3 years old. Sonographic reference values of kidney length were evaluated according to estimation formulas, and sonographic kidney volume was calculated using kidney length, width, and depth. Results This study included 33 children with mild UTD, which involved 58 kidney units. These units were graded as UTD P1 in 23 and UTD P2 in 35 units. Sonographic kidney length and volume were significantly higher in kidneys with UTD P2 that did not resolve during 3 years than in those that resolved at 3, 6 months and 1 year. The time to resolution of UTD P2 in kidneys with a length > 0.7 standard deviations at 3 months and > 1.2 standard deviations at 6 months was significantly longer than that in kidneys with a length ≤ 0.7 standard deviations at 3 months ( p < 0.01) and ≤ 1.2 standard deviations at 6months ( p = 0.01). Conclusions Increased sonographic kidney length in UTD P2 is a prognostic factor for non-resolution of kidney pelvic dilatation. Trial Registration UMIN Clinical Trial Registry: UMIN 000013286 ( https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000015493 ), with the registration date of February 26, 2014. Children Increased kidney length Mild urinary tract dilatation Kidney sonography Resolution Figures Figure 1 Introduction Congenital hydronephrosis is the most common congenital anomalies of the kidney and urinary tract (CAKUT). 1 Advances in perinatal care have led to frequent detection of urinary tract dilatation (UTD) in postnatal ultrasound (US) examinations of neonates, and fetal kidney pelvic dilation can be identified through fetal US. 2 Postnatal UTD includes such as vesicoureteral reflux (VUR), ureteropelvic junction obstruction (UPJO), posterior urethral valve (PUV). A part of postnatal UTD resolve spontaneously, which depends on the cause and the severity of the UTD. 3 In children with severe UPJO failure to relieve the obstruction may lead to kidney parenchymal impairment, emphasizing the importance of appropriate intervention to avoid a decline in kidney function. 4 In contrast, children with mild UTD, if asymptomatic, do not have a risk of kidney parenchymal impairment, and spontaneous resolution of hydronephrosis frequently occurs. 3,5-9 There is no clear consensus on the appropriate observation period or the endpoint for follow-up regarding improvement, stabilization, or resolution as milestones for pediatric mild UTD because of limited evidence in long-term outcomes. 3,10 However, in cases of mild UTD, kidney pelvic dilatation may reoccur several years after its resolution. 11 In severe cases of UTD, various researchers have examined factors contributing to the requirement for surgical intervention or remote kidney dysfunction. 12-14 Urine biomarkers, including β2 microglobulin (β2MG) and neutrophil gelatinase-associated lipocalin (NGAL), may have the potential to identify surgically obstruction. Other study demonstrated that markers of renin-angiotensin-aldosterone system (RAAS) measured in early in life could predict the need for surgery in patients with obstructive CAKUT. 15 From a different perspective, sonographic enlargement of the kidney suggested by increased kidney length have indicated irreversible pathophysiological kidney changes which consists of kidney tumors and compensatory hypertrophy with an isolated kidney. 16-21 In children with mild UTD, the risks of surgical intervention or kidney parenchymal impairment are extremely low, and other risks, which include the deterioration of UTD or the occurrence of urinary tract infections, during long-term follow-up should be focused on. Even asymptomatic and mild UTD that does not resolve may harbor the potential for progression of the severity of UTD, which suggests the need for continued observation. 22 If contributing factors for non-resolution are identified in children with mild UTD, they could be useful for their long-term follow-up. However, no studies have investigated factors contributing to the persistence or non-resolution of UTD in mild cases. Therefore, we conducted a prospective cohort study of children who were diagnosed with mild UTD during the neonatal period, and evaluated factors related to the non-resolution of UTD. Materials and Methods Patients We conducted a prospective cohort study of patients who were diagnosed with mild UTD from January 2013 to December 2021 at Kakogawa Central City Hospital. Patients were eligible if they were newly diagnosed with mild UTD when younger than 1 month old. We excluded children with congenital anomalies of the kidney and urinary tract except for mild UTD, a genetic abnormality, abnormality of the central nervous system, bowel bladder dysfunction, low birth weight, born preterm, or an external genital abnormality. We prospectively collected background data on sex, the Apgar score, and the reason for identifying mild UTD. According to previous studies, 12-21 we also collected data at periodic arrival to the hospital, such as body height, body weight, blood pressure, blood examination results including RAAS markers, urine examination results including urine biomarkers, kidney US findings including kidney diameters and volumes, and episodes of urinary tract infection. Trial Registration UMIN Clinical Trial Registry: UMIN 000013286 (https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000015493), with the registration date of February 26, 2014. Definitions Mild UTD was defined as UTD P1 or P2, and severe UTD was defined as UTD P3 according to the new classification. 23 We evaluated reference values of kidney length for US according to estimation formulas using patients’ height in Japanese children. 24 Kidney length measurements were the longest length recorded at any location. Sonographic kidney volume was calculated from outer kidney diameters using the volume formula for an ellipsoid as follows: length × width × (depth in the longitudinal section + depth in the transverse section) × 0.5 × 0.523 (ml). 25 In accordance with the postnatal kidney US diagnostic protocol, 26 resolution is defined as the findings where no UTD can be detected in two consecutive kidney US. Various skilled US technicians examined kidney US in our institution. Regimens Patients with mild UTD visited our hospital for a periodic check of blood pressure, body height, and body weight, had a blood examination, a urine examination, and kidney US performed. These examinations were performed at the ages of 1, 3, and 6 months, and at 1, 2 and 3 years. In cases where the resolution of UTD was confirmed in two consecutive kidney US examinations, the follow-up was finished as “resolution”. If kidney US in children with mild UTD showed the finding of severe UTD at a hospital visit, they finished follow-up in this cohort study and underwent a thorough check-up as patients with severe UTD. Statistical analysis All data are expressed as the median value with interquartile range or number (percentage). The Wilcoxon rank-sum test was used to examine the association between categorical values and continuous values, and Fisher’s exact test was used for two categorical values. The time to resolution of UTD was estimated using the Kaplan–Meier method and the log-rank test. The sensitivity and 1-specificity were calculated using the receiver-operating characteristic (ROC) curve, and the optimal cutoff value for distinguishing between two groups was determined. The cutoff value for generating the Kaplan–Meier method was determined using the ROC curve analysis. A p value of < 0.05 was considered statistically significant. All analyses were performed using JMP version 11.0 (SAS institute Japan Ltd., Tokyo, Japan). Results Background and resolution rate of mild UTD We included 33 children (22 boys and 11 girls) with mild UTD, which involved 58 kidney units (right kidney: 25, left kidney: 33). These kidney units were graded as UTD P1 in 23 (right kidney: 13, left: 10) and UTD P2 in 35 (right: 12, left: 23) units. The primary factor leading to the identification of mild UTD was fetal US. Other factors included screening abdominal US upon admission to the neonatal unit for other problems such as neonatal respiratory distress. The rates of resolution in all 58 units of the affected kidney at 6 months, 1 year, 2 years, and 3 years were 34.5%, 41.4%, 48.3%, and 63.8%, respectively. The rates of resolution in 23 units of UTD P1 and 35 units of UTD P2 of the affected kidney at 6 months, 1 year, 2 years, and 3 years were 43.5% and 28.6%, 56.5% and 31.4%, 60.9% and 40.0%, and 91.3% and 45.7%, respectively. There were no cases of progression of mild UTD to severe UTD, and only three children were complicated by febrile urinary tract infection. Factors associated with non-resolution in children with mild UTD Table 1 shows the comparison of the patients’ background, blood pressure, serum markers, and urine findings at each age between the groups of resolution and non-resolution of UTD in children with UTD P1 or P2 in the right or left kidneys. In children with UTD in the right kidney, plasma aldosterone activity at 6 months in the resolution group was significantly higher than that in the non-resolution group. A comparison of blood pressure at 6 months in children with hydronephrosis in the left kidney showed a significant difference between the resolution and non-resolution groups. Factors associated with non-resolution in units of UTD P2 Table 2 shows the comparison of kidney US findings in 35 kidneys of UTD P2 between the resolution and non-resolution groups. Sonographic kidney length was significantly higher in kidneys with UTD P2 that did not resolve during 3 years than in those that resolved at 1,3,6 months and 1 year. Sonographic standard deviations (SDs) of kidney length and volume were significantly higher in kidneys with UTD P2 that did not resolve during 3 years than in those that resolved at 3,6 months and 1 year. The optimal SD cutoff values for distinguishing between resolution and non-resolution were 0.7 SDs at 3 months, 1.2 SDs at 6 months, and 0.6 SDs at 1 year, respectively. A comparison of kidney US findings in 23 kidneys of UTD P1 between the resolution and non-resolution groups could not be analyzed because almost all kidneys resolved > 90% during 3 years of follow-up. Time to resolution of UTD using the Kaplan–Meier method The time to resolution of UTD was estimated using the Kaplan–Meier method with the optimal cutoff value at the 3-month and the 6-month sonographic SDs of kidney length. In the comparison between kidneys with a length ≤ 0.7 or > 0.7 SDs at the 3-month evaluation, the rates of resolution in 35 units of UTD P2 at 6 months, 1 year, 2 years, and 3 years were 38.5% and 9.1%, 47.3% and 18.2%, 68.4% and 27.3%, and 84.2% and 27.3%, respectively. The time to resolution of UTD P2 in kidneys with a length > 0.7 SDs was significantly longer than that in kidneys with a length ≤ 0.7 SDs at the 3-month evaluation (Figure 1a, p 1.2 SDs at the 6-month evaluation, the rates of resolution in 35 units of UTD P2 at 6 months, 1 year, 2 years, and 3 years were 30.0% and 13.3%, 35.4% and 20.0%, 56.9% and 20.0%, and 62.3% and 20.0%, respectively. The time to resolution of UTD P2 in kidneys with a length > 1.2 SDs was significantly longer than that in kidneys with a length ≤ 1.2 SDs at the 6-month evaluation (Figure 1b, p = 0.01). Based on the fact that the follow-up of 2 cases were finished as “resolution” at 1 year, the evaluation was conducted with 33 units instead of 35. Therefore, though data for this time point are not shown, the time to resolution of UTD P2 in kidneys with a length > 0.6 SDs was significantly longer than that in kidneys with a length ≤ 0.6 SDs at the 1 year evaluation ( p < 0.01). Discussion In this study, we examined factors contributing to the non-resolution of UTD in cases of mild UTD. As long as UTD persists the risk for adverse outcome, also in cases with mild UTD. 22 It is therefore important to identify factors associated with non-resolution. We found that a kidney length that was increased, but within the normal range, was a risk factor for the non-resolution of UTD 3 years after birth. Increased kidney length greater than the normal range indicates nephromegaly in kidney tumors, renal artery stenosis, and compensatory hypertrophy with an isolated kidney, which is due to pathophysiology involving damage and degeneration of the kidney parenchyma and interstitium. 16-21 Moreover, studies have shown a significant correlation between increased maximum longitudinal diameters using US scans and renal scarring on 99 mTc-dimercaptosuccinic acid scintigraphy. 27,28 The authors argued that the pathological consequences of parenchymal scarring represent sonographically increased kidney length, reflecting enlargement of the kidney. In cases of mild UTD, even when there is no improvement in kidney pelvic dilation, they are not likely to have histological changes in the kidney parenchyma and interstitium. Maintaining normal kidney function while showing no differences in markers of urine β2MG reflecting interstitial damage may also support this possibility. Kidneys with mild UTD do not show abnormal US findings other than kidney pelvic dilation. Generally, the technique of measurement for kidney length has been the basis of radiological quantification of kidney development. 29 If the findings of kidney US are outside of the normal range along with the body’s growth, the identification of CAKUT, which was previously undetectable through conventional imaging studies, is possible. In our study, a kidney length > 1.2 SDs at 6 months was within the normal range, and abnormal findings were limited to dilation of the kidney pelvis. In mild UTD, patients showing irreversible changes associated with kidney pelvic dilation can show kidney length values close to the upper limit even within the normal range. In pediatric patients with severe UTD including UPJO, the primary goal is to prevent renal histological damage. Research on this condition has focused on factors contributing to surgical indications and a decline in kidney function. 4 The pathophysiology of severe UTD is presumed to reflect renal parenchymal or interstitial damage associated with elevated intrapelvic pressure and renal reflux. Additionally, heterogeneous biomarkers, such as urine β2MG and NGAL, have been identified as contributing factors to this condition. 12-14 In this study, urine β2MG was not found to be associated with the outcomes of mild UTD. Patients with mild UTD do not have renal histological damage or biomarker changes unless complicated by febrile urinary tract infections or exacerbation of UTD. In addition to urinary β2MG, we analyzed plasma renin and aldosterone activity as components of the RAAS, which plays a crucial role in renal genesis. 30 Comparison to the non-resolution group of children with mild UTD in the right kidney, plasma aldosterone activity at 6 months in the resolution group was significantly higher. While markers of RAAS measured in early in life could predict the need for surgery in patients with obstructive CAKUT, 15 our results of plasma aldosterone activity were associated with the resolution of mild UTD. We were unable to analyze above result in this study, and further functional studies will be necessary in the future. Matsui et al. conducted studies on recurrence after spontaneous resolution of mild UTD, and found that long-term follow-up was unnecessary. 31 There was a report of mild UTD worsening after temporary resolution, even 5–9 years later, but this was an extremely rare occurrence. 11 When exacerbation of UTD occurs, it often presents with symptoms, such as abdominal pain, vomiting, and gross hematuria. 31 Based on opinions emphasizing the importance of reevaluation at the time of symptom appearance or the importance of long-term periodic follow-up, there is no clear consensus on the appropriate management for follow-up of pediatric mild UTD. In our study, sonographically increased kidney length within the normal range was a factor related to non-resolution of kidney pelvic dilation, suggesting that it is important in the management of children with mild UTD. This study has several limitations. First, the number of included children was small. Second, most cases of UTD requiring surgery occur in children aged 3–4 years or younger, and the estimated period in this study was set at 3 years. 32 Worsening of UTD and the occurrence of urinary tract infections in pediatric patients with mild UTD are critical factors, and focusing on these factors as primary outcomes is desirable. There were no cases of worsening UTD and only three cases of urinary tract infections in our 3-year study. However, as long as mild UTD persists, the potential for the risk of these critical outcomes occurring in the future remains. Third, VCUG was not performed as part of the evaluation for mild UTD, so it is possible that mild VUR may have been present among the causes of UTD in the study population. In conclusion, this study suggests that an increased sonographic kidney length in UTD P2 with mild UTD is a prognostic factor for non-resolution of kidney pelvic dilatation. The identification of factors for non-resolution could be useful for long-term follow-up. Declarations Competing interests The authors report no conflicts of interest relevant to this article. Funding information Our study received no specific grant from any funding agency in the public, commercial, or not-for-profit sections. Ethics approval All procedures performed in this study involving human participants were in accordance with the ethical standards of the Kakogawa Central City Hospital Ethics Board. The study was conducted (approval number: 25-19) in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consent was obtained from all patients’ parents for this study according to institutional ethics. Consent to participate/consent to publish Before enrollment, written informed consent was obtained from all patients and their parents for this study in accordance with guidelines. Author contributions S.I. prepared the manuscript. S.I. and J.F. collected the clinical data. A.N., T.M. revised the article. All the authors have read and approved the final manuscript. Acknowledgments We thank Ellen Knapp, PhD, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript. Availability of data and material Data from this study can be obtained from the corresponding authors at reasonable request. References Blyth B, Snyder HM, Duckett JW (1993) Antenatal diagnosis and subsequent management of hydronephrosis. J Urol 149: 693-698. https://doi.org/10.1016/s0022-5347(17)36185-2 Mallik M, Watson AR (2008) Antenatally detected urinary tract abnormalities: more detection but less action. Pediatr Nephrol 23: 897-904. https://doi.org/10.1007/s00467-008-0746-9 Herthelius M (2023) Antenatally detected urinary tract dilatation: long-term outcome. Pediatr Nephrol 38: 3221-3227. https://doi: 10.1007/s00467-023-05907-z Onen A (2007) An alternative grading system to refine the criteria for severity of hydronephrosis and optimal treatment guideline in nepnates with primary UPJ-type hydronephrosis. J Pediatr Urol 3: 200-205. https://doi.org/10.1016/j.jpurol.2006.08.002 Barbosa JA, Chow JS, Benson CB, Yorioka MA, Bull AS, Retik AB, Nguyen HT (2012) Postnatal longitudinal evaluation of children diagnosed with prenatal hydronephrosis: insights in natural history and referral pattern. Prenat Diagn 32: 1242-1249. https://doi.org/10.1002/pd.3989 Yang Y, Hou Y, Niu ZB, Wang CL (2010) Long-term follow-up and management of prenatally detected, isolated hydronephrosis. J Pediatr Surg 45: 1701-1706. https://doi.org/ 10.1016/j.jpedsurg.2010.03.030. Passerotti CC, Kalish LA, Chow J, Passerotti AM, Recabal P, Cendron M, Lee RS, Lopez AB, Retik AB, Nguyen HT (2011) The predictive value of the first postnatal ultrasound in children with antenatal hydronephrosis. J Pediatr Urol 7: 128-136. https://doi.org/10.1016/j.jpurol.2010.09.007 Sidhu G, Beyene J, Rosenblum ND (2006) Outcome of isolated antenatal hydronephrosis: a systematic review and meta-analysis. Pediatr Nephrol 21: 218-224. https://doi.org/10.1007/s00467-005-2100-9 Herthelius M, Axelsson R, Lidefelt KJ (2020) Antenatally detected urinary tract dilatation: a 12-15-year follow-up. Pediatr Nephrol 35: 2129-2135. https://doi: 10.1007/s00467-020-04659-4 Nguyen HT, Herndon CDA, Cooper C, Gatti J, Kirsch A, Kokorowski P, Lee R, Perez-Brayfield M, Metcalfe P, Yerkes E, Cendron, Cambell JB (2010) The society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis. J Pediatr Urol 6; 212-231. https://doi.org/10.1016/j.jpurol.2010.02.205 Rigas A, Karamanolakis D, Bogdanos I, Stephanidis A, Androulakakis PA (2003) Pelviureteric junction obstruction by crossing renal vessels: clinical and imaging features. BJU Int 92: 101-103. https://doi.org/10.1046/j.1464-410x.2003.04265.x Papachristou F, Pavlaki A, Printza N (2014) Urinary and serum biomarkers in ureteropelvic junction obstruction: a systematic review. Biomarkers 19: 531-540. https://doi.org/10.3109/1354750X.2014.943292 Madsen MG, Nørregaard R, Palmfeldt J, Olsen LH, Frøkiær J, Jørgensen TM (2013) Epidermal growth factor and monocyte chemotactic peptide-1: potential biomarkers of urinary tract obstruction in children with hydronephrosis. J Pediatr Urol 9: 838-845. https://doi.org/10.1016/j.jpurol.2012.11.011 Cost NG, Noh PH, Devarajan P, Ivancic V, Reddy PP, Minevich E, Bennett M, Haffner C, Schulte M, DeFoor Jr WR (2013) Urinary NGAL levels correlate with differential renal function in patients with ureteropelvic junction obstruction undergoing pyeloplasty. J Urol 190: 1462-1467. https://doi.org/10.1016/j.juro.2013.05.003 Marzuillo P, Palma PL, Sessa AD, Roberti A, Torino G, De Lucia M, Del Giudice EM, Guarino S, Di Lorio G (2023) Early-in-Life Serum Aldosterone Levels Could Predict Surgery in Patients with Obstructive Congenital Anomalies of the Kidney and Urinary Tract: A Pilot Study. J Clin Med 12: 1921. https://doi: 10.3390/jcm12051921. Shaikh N, Ewing AL, Bhatnagar S, Hoberman A (2010) Risk of renal scarring in children with a first urinary tract infection: a systematic review. Pediatrics 126: 1084-1091. https://doi.org/10.1542/peds.2010-0685 Wennerstrom M, Hansson S, Jodal U, Stokland E (2000) Primary and acquired renal scarring in boys and girls with urinary tract infection. J Pediatr 136: 30-34. https://doi.org/10.1016/s0022-3476(00)90045-3 Saxena AB, Busque S, Arjane P, Myers BD, Tan JC (2004) Preoperative renal volumes as a predictor of graft function in living donor transplantation. Am J Kidney Dis 44: 877-885. Zumrutdal AO, Turan C, Cetin F, Adanali S (2002) Relationship between renal size and hypertension in patients with chronic renal failure. Nephron 90: 145-147. https://doi.org/10.1159/000049034 Gandy SJ, Armoogum K, Nicholas RS, McLeay TB, Houston JG (2007) A clinical MRI investigation of the relationship between kidney volume measurements and renal function in patients with renovascular disease. Br J Radiol 80: 12-20. https://doi.org/10.1259/bjr/11148990 Troell S, Berg U, Johansson B, Wikstad I (1984) Ultrasonographic renal parenchymal volume related to kidney function and renal parenchymal area in children with recurrent Gatti JM, Broecker BH, Scherz HC, Perez-Brayfield M, Kirsch AJ (2001) Antenatal hydronephrosis with postnatal resolution: how long are postnatal studies warranted? Urology 57: 1178. https://doi.org/10.1016/s0090-4295(00)00933-xhttps://doi.org/10.1177/028418518402500512 Gatti JM, Broecker BH, Scherz HC, Perez-Brayfield M, Kirsch AJ (2001) Antenatal hydronephrosis with postnatal resolution: how long are postnatal studies warranted? Urology 57: 1178. https://doi.org/10.1016/s0090-4295(00)00933-x Nguyen HT, Benson CB, Bromley B, Cambell JB, Chow J, Coleman B, Cooper C, Crino J, Darge K, Herndon CDA, Odibo AO, Somers MJG, Stein DR (2014) Multidisciplinary consensus on the classification of prenatal and postnatal urinary tract dilation (UTD classification system). J Pediatr Urol 10:982-998. https://doi: 10.1016/j.jpurol.2014.10.002. Fujita N, Uemura O, Harada R,Matsumura C, Sakai T, Hamasaki Y, Kamei K, Nishi K, Kaneko T, Ishikura K, Gotoh Y; the pediatric CKD Study Group in Japan in conjunction with the Committee of Measures for Pediatric CKD of the Japanese Society of Pediatric Nephrology (2022) Ultrasonographic reference values and a simple yet practical formula for estimating average kidney length in Japanese children. Clin Exp Nephrol 26: 808-818. https://doi.org/10.1007/s10157-022-02205-0 Dinkel E, Ertel M, Dittrich M, Peters H, Berres M, Schulte-Wissermann H (1985) Kidney size in childhood sonographical growth charts for kidney length and volume. Pediatr Radiol 15: 38-43. https://doi.org/10.1007/BF02387851 Aksu N, Yavascan O, Kangin M, Kara OD, Aydin Y, Erdogan H, Tuncel TC, Cetinkaya E, Ozbay E, Sandikcioglu (2005). Postnatal management of infants with antenatally detected hydronephrosis. Pediatr Nephrol 20: 1253-1259. https://doi: 10.1007/s00467-005-1989-3. Epub 2005 Jul 16. Peratoner L, Pennesi M, Bordugo A, Melega R, Sorce P, Travan L, Minisini S, Zennaro F, Ronch LD (2005) Kidney length and scarring in children with urinary tract infection: importance of ultrasound scans. Abdom Imaging 30: 780-785. https://doi.org/10.1007/s00261-005-0324-6 Bouissou F, Munzer C, Decramer S, Rousse B, Novo R, Morin D, Lavocat MP, Guyot C, Taque S, Fischbach M, Ouhayoun E; French Society of Nuclear Medicine and Moleculat Imaging: Loirat C; French Society of Pediatric Nephrology (2008) Prospective randomized trial comparing short and long intravenous antibiotic treatment of acute pyelonephritis in children: dimercaptosuccinic acid scintigraphic evaluation at 9 months. Pediatrics 121: e553-560. https://doi.org/10.1542/peds.2006-3632 Klare B, Geiselhardt B, Wesch H, Scharer K, Immich H, Willich E (1980) Radiological kidney size in childhood. Pediatr Radiol 9: 153-160. https://doi.org/10.1007/BF01464310 Yosypiv IV (1996) Activation of angiotensin0generating systems in the developing kidney. Hypertension 2: 281-286. https://doi.org/10.1161/01.hyp.27.2.281 Matsui F, Shimada K, Matsumoto F, Takano S (2008) Late recurrence of symptomatic hydronephrosis in patients with prenatally detected hydronephrosis and spontaneous improvement. J Urol 180: 322-325. https://doi.org/10.1016/j.juro.2008.03.065 Chertin B, Pollack A, Koulikov D, Rabinowitz R, Hain D, Hadas-Halpren I, Farkas A (2006) Conservative treatment of ureteropelvic junction obstruction in children with antenatal diagnosis of hydronephrosis: Lessons learned after 16 years of follow-up. Eur Urol. 49:734-738. https://doi: 10.1016/j.eururo.2006.01.046 Tables Table 1 Comparison of clinical characteristics in each kidney between resolution and non-resolution group Children with mild UTD in the right kidney n=25 Children with mild UTD in the left kidney n=33 Resolution n=16 Non-resolution n=9 Resolution n=21 Non-resolution n=12 Characteristics at birth and during neonatal periods Boy : Girl 11 : 5 6 : 3 13 : 8 9 : 3 Identification in fetal US, n (%) 8 (50.0%) 7 (77.8%) 11 (52.3%) 6 (50.0%) APGAR score, 1 † 8 (8-9) 8 (7-9) 9 (8-9) 8 (7-9) APGAR score, 5 ‡ 9 (9-10) 9 (8.5-10) 9 (9-10) 9 (8-9) Plasma renin activity (ng/mg/h) 15.5 (6.8-40.1) 10.5 (5.1-24.3) 20.8 (7.6-43.7) 12.1 (4.0-24.7) Plasma aldosterone activity (pg/ml) 652 (586-1315) 700 (458-1300) 992 (748-1583) 1130 (781-1190) Serum Cr level (mg/dl) 0.22 (0.15-0.25) 0.19 (0.16-0.24) 0.39 (0.27-0.48) 0.42 (0.23-0.65) Serum LDH level (mg/dl) 257 (228-267) 226 (187-266) 390 (283-447) 353 (316-469) Urine β2MG/Cr ratio (μg/g・Cr) 7.4 (4.8-12.3) 10.6 (6.7-16.7) 15.4 (8.2-38.1) 14.5 (2.8-29.0) Characteristics at 1 month Plasma renin activity (ng/mg/h) 15.5 (6.8-40.1) 10.5 (5.1-24.3) 15.5 (7.9-28.2) 14.3 (6.3-26.9) Plasma aldosterone activity (pg/ml) 652 (586-1315) 700 (458-1300) 1210 (603-1500) 652 (516-1140) Serum Cr level (mg/dl) 0.22 (0.15-0.25) 0.19 (0.16-0.24) 0.21 (0.17-0.25) 0.21 (0.15-0.23) Serum LDH level (mg/dl) 257 (228-267) 226 (187-266) 256 (226-271) 242 (225-262) Urine β2MG/Cr ratio (μg/g・Cr) 7.4 (4.8-12.3) 10.6 (6.7-16.7) 7.4 (4.8-16.5) 8.1 (3.5-15.9) Characteristics at 3 months Plasma renin activity (ng/mg/h) 14.9 (7.5-30.1) 9.7 (4.5-26.4) 25.7 (7.2-36.0) 13.7 (4.2-20.7) Plasma aldosterone activity (pg/ml) 841 (402-1125) 424 (314-639) 829 (409-1220) 488 (391-889) Serum Cr level (mg/dl) 0.19 (0.16-0.25) 0.16 (0.14-0.21) 0.19 (0.16-0.23) 0.17 (0.14-0.21) Serum LDH level (mg/dl) 254 (237-283) 227 (205-259) 254 (234-284) 246 (225-264) Urine β2MG/Cr ratio (μg/g・Cr) 0.91 (0.62-1.34) 0.87 (0.80-1.66) 0.91 (0.58-1.70) 0.85 (0.75-1.32) Characteristics at 6 months Systolic blood pressure (mmHg) 93 (82-104) 100 (74-104) 91 (80-100) * 100 (96-106) * Plasma renin activity (ng/mg/h) 16.0 (6.7-50.0) 16.4 (5.8-24.2) 16.4 (6.0-40.7) 16.0 (5.7-34.2) Plasma aldosterone activity (pg/ml) 934 (440-2130) * 435 (199-690) * 584 (296-1400) 672 (240-1170) Serum Cr level (mg/dl) 0.19 (0.17-0.22) 0.17 (0.14-0.22) 0.12 (0.17-0.22) 0.18 (0.14-0.22) Serum LDH level (mg/dl) 267 (243-338) 254 (243-337) 266 (244-322) 272 (249-316) Urine β2MG/Cr ratio (μg/g・Cr) 0.46 (0.36-1.69) 0.41 (0.37-0.81) 0.42 (0.34-0.74) 0.53 (0.41-0.89) Characteristics at 1 year ‖ Systolic blood pressure (mmHg) 94 (83-103) 106 (100-112) 99 (88-111) 99 (92-105) Plasma renin activity (ng/mg/h) 12.5 (4.5-33.3) 10.6 (8.5-13.4) 14.3 (5.7-24.4) 11.7 (10.5-16.4) Plasma aldosterone activity (pg/ml) 288 (213-700) 381 (200-529) 373 (150-547) 233 (144-439) Serum Cr level (mg/dl) 0.20 (0.18-0.21) 0.20 (0.17-0.22) 0.20 (0.19-0.23) 0.20 (0.17-0.22) Serum LDH level (mg/dl) 273 (236-320) 273 (231-309) 274 (237-316) 273 (256-308) Urine β2MG/Cr ratio (μg/g・Cr) 0.65 (0.32-0.93) 0.29 (0.21-0.54) 0.43 (0.27-0.65) 0.55 (0.27-0.96) Characteristics at 2 years ¶ Systolic blood pressure (mmHg) 97 (94-111) 110 (94-121) 97 (88-109) 101 (96-109) Plasma renin activity (ng/mg/h) 7.5 (6.3-22.2) 5.2 (3.4-21.4) 8.7 (4.2-21.4) 6.8 (5.5-10.9) Plasma aldosterone activity (pg/ml) 165 (108-319) 197 (165-280) 180 (112-180) 175 (120-254) Serum Cr level (mg/dl) 0.22 (0.17-0.27) 0.20 (0.19-0.26) 0.24 (0.20-0.26) 0.22 (0.18-0.27) Serum LDH level (mg/dl) 255 (213-280) 256 (226-281) 256 (224-266) 259 (234-279) Urine β2MG/Cr ratio (μg/g・Cr) 0.24 (0.19-0.70) 0.31 (0.29-0.41) 0.30 (0.23-0.43) 0.31 (0.24-0.40) Characteristics at 3 years ¶ Systolic blood pressure (mmHg) 99 (90-115) 99 (93-113) 99 (92-105) 95 (86-113) Plasma renin activity (ng/mg/h) 5.9 (3.1-8.9) 7.8 (4.3-13.0) 7.8 (4.4-11.7) 4.4 (3.4-10.7) Plasma aldosterone activity (pg/ml) 129 (44-234) 139 (61-153) 142 (61-259) 134 (108-185) Serum Cr level (mg/dl) 0.27 (0.21-0.30) 0.24 (0.23-0.29) 0.27 (0.24-0.29) 0.24 (0.23-0.30) Serum LDH level (mg/dl) 231 (194-263) 235 (210-270) 232 (195-276) 246 (213-265) Urine β2MG/Cr ratio (μg/g・Cr) 0.22 (0.14-0.32) 0.24 (0.19-0.35) 0.23 (0.16-0.32) 0.26 (0.22-0.35) UTD; urinary tract dilatation, US; ultrasound, Cr; creatinine, β2MG; β2 microglobulin,*; p<0.05, †; estimated in 29 neonates, ‡; estimated in 29 neonates, ‖;estimated in 28 children, ¶; estimated in 21 children, Table 2 Comparison of kidney ultrasound of urinary tract dilatation P2 between the resolution and non-resolution groups. UTD P2 Resolution n=16 Non-resolution n=19 Characteristics at birth Length of kidney (mm) 44.4 (41.5-46.2) 46.4 (44.0-53.4) Length of kidney (SD) -1.08 (-1.67-0.81) -0.73 (-1.16-0.45) Volume of kidney (ml) 11.0 (9.1-13.5) 12.4 (9.5-13.5) Characteristics at 1month Length of kidney (mm) 49.5 (46.3-51.1) * 52.7 (48.5-55.7) * Length of kidney (SD) -0.02 (-0.79-0.27) -0.66 (-0.33-1.06) Volume of kidney (ml) 14.9 (11.5-17.9) 17.4 (14.5-23.4) Characteristics at 3 months Length of kidney (mm) 52.9 (50.1-55.1) * 58.1 (56.5-59.8) * Length of kidney (SD) 0.53 (-0.24-1.13) * 1.13 (0.74-2.03) * Volume of kidney (ml) 19.1 (14.5-19.8) * 26.3 (21.3-29.3) * Characteristics at 6 months Length of kidney (mm) 56.5 (53.3-59.8) * 62.3 (59.3-65.0) * Length of kidney (SD) 0.45 (-0.13-1.06) * 1.69 (0.86-2.10) * Volume of kidney (ml) 22.0 (18.9-24.1) * 24.8 (20.0-31.5) * Characteristics at 1 year † Length of kidney (mm) 57.7 (56.0-60.3) * 62.5 (60.8-68.5) * Length of kidney (SD) 0.05 (-0.42-0.36) * 0.87 (0.57-1.67) * Volume of kidney (ml) 22.7 (17.9-29.2) * 29.3 (25.2-38.9) * UTD; urinary tract dilatation, SD; Standard deviation, *; p<0.05, †; estimated in 33 kidney including 15 of resolution and 18 of non-resolution Cite Share Download PDF Status: Published Journal Publication published 07 Mar, 2025 Read the published version in Pediatric Nephrology → Version 1 posted Editorial decision: Major Revisions Needed 18 Nov, 2024 Reviewers agreed at journal 24 Oct, 2024 Reviewers invited by journal 23 Oct, 2024 Editor assigned by journal 23 Oct, 2024 First submitted to journal 23 Oct, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5319229","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":369675003,"identity":"91ae51ce-18c3-4ea5-974d-84345315bb22","order_by":0,"name":"Shingo Ishimori","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAElEQVRIie3RP0sDMRjH8V8pxOXRWxN6eG/hKTcJom+lx0FdHBw7Bg7SRXCt+CYcHSMHnQ67CroUwTkFh4IHmh5uxbSjYL7LA4EP+QfEYn8x2dObQSKpLAOnqehW9yGJnI+ugDHtQX6m0pfsgJp2niu7q8zyY4KUrR3eu3ZBR7K0OHn4nfDr4zRPGxDXuhzemhcScjyCagJEFmagzBf5Xeb5ofaEGoYygYPNOuJ3scX0k9onTxYuSPBcGLXyROkSOQlL4uAaQcKeDNB0jwx/l9ITwzZ0l2x28a7WE5yL5Maxa8+Os6q/fFOBF9vU3/qLWukw6a23VlY7SCwWi/2rvgGdjk123UUcGgAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-3863-2743","institution":"Kobe University Graduate School of Medicine School of Medicine: Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu","correspondingAuthor":true,"prefix":"","firstName":"Shingo","middleName":"","lastName":"Ishimori","suffix":""},{"id":369675004,"identity":"e4a4cbc9-bac8-4e43-a176-490148d23dc7","order_by":1,"name":"Junya Fujimura","email":"","orcid":"","institution":"Department of Pediatrics, Kakogawa Central City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Junya","middleName":"","lastName":"Fujimura","suffix":""},{"id":369675005,"identity":"2ca0de3e-cb1a-49d3-b5ba-ba6c49a14f63","order_by":2,"name":"Atsushi Nishiyama","email":"","orcid":"","institution":"Department of Pediatrics, Kakogawa Central City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Atsushi","middleName":"","lastName":"Nishiyama","suffix":""},{"id":369675006,"identity":"4a99189c-315f-4681-a81b-9f47f51a9e7d","order_by":3,"name":"Takeshi Morisawa","email":"","orcid":"","institution":"Department of Pediatrics, Kakogawa Central City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Takeshi","middleName":"","lastName":"Morisawa","suffix":""}],"badges":[],"createdAt":"2024-10-23 13:18:59","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5319229/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5319229/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00467-025-06733-1","type":"published","date":"2025-03-07T15:58:44+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":67617968,"identity":"afeb32e2-0ecc-4e77-8e3f-980d9393d80a","added_by":"auto","created_at":"2024-10-28 06:41:09","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":36819,"visible":true,"origin":"","legend":"\u003cp\u003eTime to resolution of urinary tract dilatation using the Kaplan–Meier method. UTD; urinary tract dilatation.\u003c/p\u003e\n\u003cp\u003ea) Time to resolution of UTD P2 based on kidney length at the 3-month evaluation. The dashed line indicates UTD P2 in kidneys with a length ≤ 0.7 standard deviations. The solid line indicates UTD P2 in kidneys with a length \u0026gt; 0.7 standard deviations. A significant difference was observed between the two groups (\u003cem\u003ep \u003c/em\u003e\u0026lt; 0.01).\u003c/p\u003e\n\u003cp\u003eb) Time to resolution of UTD P2 based on kidney length at the 6-month evaluation. The dashed line indicates UTD P2 in kidneys with a length ≤ 1.2 standard deviations. The solid line indicates UTD P2 in kidneys with a length \u0026gt; 1.2 standard deviations. A significant difference was observed between the two groups (\u003cem\u003ep \u003c/em\u003e= 0.01).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5319229/v1/6851d023c8c5b320ce254a20.png"},{"id":78190832,"identity":"cfc65d57-ef00-4cfa-a0de-29b1fb776ae9","added_by":"auto","created_at":"2025-03-10 19:51:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":761831,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5319229/v1/b4324b7a-1e58-4d9e-9f51-b13eea0cad4d.pdf"}],"financialInterests":"","formattedTitle":"Increased kidney length in mild urinary tract dilatation is a significant prognostic factor for non-resolution","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCongenital\u0026nbsp;hydronephrosis is the most common congenital anomalies of the kidney and urinary tract (CAKUT).\u003csup\u003e1\u003c/sup\u003e Advances in perinatal care have led to frequent detection of urinary tract dilatation (UTD) in postnatal ultrasound (US) examinations of neonates, and fetal kidney pelvic dilation can be identified through fetal US.\u003csup\u003e2\u003c/sup\u003e Postnatal UTD includes such as vesicoureteral reflux (VUR), ureteropelvic junction obstruction (UPJO), posterior urethral valve (PUV). A part of postnatal UTD resolve spontaneously, which depends on the cause and the severity of the UTD.\u003csup\u003e3\u003c/sup\u003e In children with severe UPJO failure to relieve the obstruction may lead to kidney parenchymal impairment, emphasizing the importance of appropriate intervention to avoid a decline in kidney function.\u003csup\u003e4\u003c/sup\u003e In contrast, children with mild UTD, if asymptomatic, do not have a risk of kidney parenchymal impairment, and spontaneous resolution of hydronephrosis frequently occurs.\u003csup\u003e3,5-9\u003c/sup\u003e There is no clear consensus on the appropriate observation period or the endpoint for follow-up regarding improvement, stabilization, or resolution as milestones for pediatric mild UTD because of limited evidence in long-term outcomes.\u003csup\u003e3,10\u003c/sup\u003e However, in cases of mild UTD, kidney pelvic dilatation may reoccur several years after its resolution.\u003csup\u003e11\u003c/sup\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn severe cases of UTD, various researchers have examined factors contributing to the requirement for surgical intervention or remote kidney dysfunction.\u003csup\u003e12-14\u003c/sup\u003e Urine biomarkers, including \u0026beta;2 microglobulin (\u0026beta;2MG) and neutrophil gelatinase-associated lipocalin (NGAL), may have the potential to identify surgically obstruction. Other study demonstrated that markers of renin-angiotensin-aldosterone\u0026nbsp;system (RAAS) measured in early in life could predict the need for surgery in patients with obstructive CAKUT.\u003csup\u003e15\u003c/sup\u003e From a different perspective, sonographic\u0026nbsp;enlargement of the kidney suggested by increased kidney length have indicated irreversible pathophysiological kidney changes which consists of\u0026nbsp;kidney tumors and compensatory hypertrophy with an isolated kidney.\u003csup\u003e16-21\u003c/sup\u003e In children with mild UTD, the risks of surgical intervention or kidney parenchymal impairment are extremely low, and other risks, which include the deterioration of UTD or the occurrence of urinary tract infections, during long-term follow-up should be focused on. Even asymptomatic and mild UTD that does not resolve may harbor the potential for progression of the severity of UTD, which suggests the need for continued observation.\u003csup\u003e22\u003c/sup\u003e If contributing factors for non-resolution are identified in children with mild UTD, they could be useful for their long-term follow-up. However, no studies have investigated factors contributing to the persistence or non-resolution of UTD in mild cases. Therefore, we conducted a prospective cohort study of children who were diagnosed with mild UTD during the neonatal period, and evaluated factors related to the non-resolution of UTD.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePatients\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted a prospective cohort study of patients\u0026nbsp;who were\u0026nbsp;diagnosed\u0026nbsp;with\u0026nbsp;mild\u0026nbsp;UTD\u0026nbsp;from January 2013 to December 2021 at Kakogawa Central City Hospital.\u0026nbsp;Patients were eligible if they were newly diagnosed with mild\u0026nbsp;UTD\u0026nbsp;when younger than 1 month old.\u0026nbsp;We excluded children with\u0026nbsp;congenital anomalies of the kidney and urinary tract\u0026nbsp;except for mild\u0026nbsp;UTD,\u0026nbsp;a\u0026nbsp;genetic abnormality, abnormality of the central nervous system, bowel bladder dysfunction, low birth weight, born preterm, or an external genital abnormality. We prospectively collected background data on sex, the Apgar score,\u0026nbsp;and the reason for identifying\u0026nbsp;mild\u0026nbsp;UTD. According to previous studies,\u003csup\u003e12-21\u003c/sup\u003e we also collected data at periodic arrival to the hospital, such as\u0026nbsp;body height, body weight, blood pressure, blood examination results including RAAS\u0026nbsp;markers, urine examination results including urine biomarkers,\u0026nbsp;kidney\u0026nbsp;US findings including kidney diameters and volumes, and episodes of urinary tract infection.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTrial Registration\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUMIN Clinical Trial Registry: UMIN 000013286 (https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000015493), with the registration date of February 26, 2014.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDefinitions\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMild UTD was defined as UTD P1 or P2, and severe UTD was defined as UTD P3 according to the new classification.\u003csup\u003e23\u003c/sup\u003e We evaluated reference values of\u0026nbsp;kidney length for\u0026nbsp;US according to estimation formulas using patients\u0026rsquo; height in Japanese children.\u003csup\u003e24\u003c/sup\u003e Kidney length measurements were the longest length recorded at any location. Sonographic kidney volume was calculated from outer kidney diameters using the volume formula for an ellipsoid as follows: length \u0026times; width \u0026times; (depth in the longitudinal section + depth in the transverse section) \u0026times; 0.5 \u0026times; 0.523 (ml).\u003csup\u003e25\u003c/sup\u003e In accordance with the postnatal\u0026nbsp;kidney US\u0026nbsp;diagnostic protocol,\u003csup\u003e26\u003c/sup\u003e resolution is defined as the findings where no UTD can be detected in two consecutive kidney\u0026nbsp;US.\u0026nbsp;Various skilled US technicians examined\u0026nbsp;kidney\u0026nbsp;US in our institution.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eRegimens\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients with mild\u0026nbsp;UTD visited our hospital for a periodic check of\u0026nbsp;blood pressure, body height, and body weight, had\u0026nbsp;a blood examination, a urine examination, and\u0026nbsp;kidney\u0026nbsp;US performed. These examinations were performed at the ages of 1, 3, and 6 months, and at 1, 2 and 3 years. In cases where the resolution of\u0026nbsp;UTD\u0026nbsp;was confirmed in two consecutive\u0026nbsp;kidney\u0026nbsp;US examinations, the follow-up was finished as \u0026ldquo;resolution\u0026rdquo;. If\u0026nbsp;kidney\u0026nbsp;US in children with mild\u0026nbsp;UTD\u0026nbsp;showed the finding of severe UTD at a hospital visit, they finished follow-up in this\u0026nbsp;cohort study and underwent a thorough check-up as patients with severe UTD.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eStatistical analysis\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data are expressed as the median value with interquartile range or number (percentage). The Wilcoxon rank-sum test was used to examine the association between categorical values and continuous values, and Fisher\u0026rsquo;s exact test was used for two categorical values. The time to resolution of UTD was estimated using the Kaplan\u0026ndash;Meier method and the log-rank test.\u0026nbsp;The sensitivity and 1-specificity were calculated using the receiver-operating characteristic (ROC) curve, and the optimal cutoff value for distinguishing between two groups was determined. The cutoff value for generating the\u0026nbsp;Kaplan\u0026ndash;Meier method was determined using the\u0026nbsp;ROC curve analysis.\u0026nbsp;A \u003cem\u003ep\u003c/em\u003e value of \u0026lt; 0.05 was considered statistically significant. All analyses were performed using JMP version 11.0 (SAS institute Japan Ltd., Tokyo, Japan).\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eBackground and resolution rate of mild UTD\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe included 33 children (22 boys and 11 girls) with\u0026nbsp;mild\u0026nbsp;UTD, which involved 58 kidney units (right kidney: 25, left kidney: 33). These kidney units were graded as UTD P1 in 23 (right kidney: 13, left: 10) and UTD P2 in 35 (right: 12, left: 23) units. The primary factor leading to the identification of\u0026nbsp;mild\u0026nbsp;UTD was fetal US. Other factors included screening abdominal US upon admission to the neonatal unit for other problems such as\u0026nbsp;neonatal respiratory distress.\u003c/p\u003e\n\u003cp\u003eThe rates of resolution in all 58 units of the affected kidney at 6 months, 1 year, 2 years, and 3 years were 34.5%, 41.4%, 48.3%, and 63.8%, respectively. The rates of resolution in 23 units of UTD P1 and 35 units of UTD P2 of the affected kidney at 6 months, 1 year, 2 years, and 3 years were 43.5% and 28.6%, 56.5% and 31.4%, 60.9% and 40.0%, and 91.3% and 45.7%, respectively. There were no cases of progression of mild UTD\u0026nbsp;to severe UTD, and only three children were complicated by febrile\u0026nbsp;urinary tract infection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFactors associated with non-resolution in children with mild UTD\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable 1 shows the comparison of the patients’ background, blood pressure, serum markers, and urine findings at each age between the groups of resolution and non-resolution of UTD in children with UTD P1 or P2 in the right or left kidneys. In children with UTD in the right kidney, plasma aldosterone activity at 6 months in the resolution group was significantly higher than that in the non-resolution group. A comparison of blood pressure at 6 months in children with hydronephrosis in the left kidney showed a significant difference between the resolution and non-resolution groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFactors associated with non-resolution in units of UTD P2\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable 2 shows the comparison of kidney US findings in 35 kidneys of UTD P2 between the resolution and non-resolution groups. Sonographic kidney length was significantly higher in kidneys with UTD P2 that did not resolve during 3 years than in those that resolved at 1,3,6 months and 1 year. Sonographic standard deviations (SDs) of kidney length and volume were significantly higher in kidneys with UTD P2 that did not resolve during 3 years than in those that resolved at 3,6 months and 1 year. The optimal SD cutoff values for distinguishing between resolution and non-resolution were 0.7 SDs at 3 months, 1.2 SDs at 6 months, and 0.6 SDs at 1 year, respectively. A comparison of kidney US findings in 23 kidneys of UTD P1 between the resolution and non-resolution groups could not be analyzed because almost all kidneys resolved \u0026gt; 90% during 3 years of follow-up.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTime to resolution of UTD using the Kaplan–Meier method\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe time to resolution of UTD was estimated using the Kaplan–Meier method with\u0026nbsp;the optimal cutoff value\u0026nbsp;at the 3-month and the 6-month sonographic SDs of kidney length. In the comparison between kidneys with a length ≤ 0.7 or \u0026gt; 0.7 SDs at the 3-month evaluation, the rates of resolution in 35 units of UTD P2 at 6 months, 1 year, 2 years, and 3 years were 38.5% and 9.1%, 47.3% and 18.2%, 68.4% and 27.3%, and 84.2% and 27.3%, respectively. The time to resolution of UTD P2 in kidneys with a length \u0026gt; 0.7 SDs\u0026nbsp;was significantly longer than that in\u0026nbsp;kidneys with a length ≤ 0.7 SDs\u0026nbsp;at the 3-month evaluation\u0026nbsp;(Figure 1a,\u0026nbsp;\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.01).\u0026nbsp;In the comparison between kidneys with a length ≤ 1.2 or \u0026gt; 1.2 SDs at the 6-month evaluation, the rates of resolution in 35 units of UTD P2 at 6 months, 1 year, 2 years, and 3 years were 30.0% and 13.3%, 35.4% and 20.0%, 56.9% and 20.0%, and 62.3% and 20.0%, respectively. The time to resolution of UTD P2 in kidneys with a length \u0026gt; 1.2 SDs\u0026nbsp;was significantly longer than that in\u0026nbsp;kidneys with a length ≤ 1.2 SDs\u0026nbsp;at the 6-month evaluation\u0026nbsp;(Figure 1b, \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.01). Based on the fact that\u0026nbsp;the follow-up\u0026nbsp;of 2 cases were\u0026nbsp;finished as “resolution”\u0026nbsp;at 1 year, the evaluation was conducted with 33\u0026nbsp;units\u0026nbsp;instead of 35. Therefore, though data for this time point are not shown, the time to resolution of UTD P2 in kidneys with a length \u0026gt; 0.6 SDs\u0026nbsp;was significantly longer than that in\u0026nbsp;kidneys with a length ≤ 0.6 SDs\u0026nbsp;at the 1 year evaluation\u0026nbsp;(\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.01).\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, we examined factors contributing to the non-resolution of UTD in cases of mild UTD. As long as UTD persists the risk for adverse outcome, also in cases with mild UTD.\u003csup\u003e22\u003c/sup\u003e It is therefore important to identify factors associated with non-resolution.\u003c/p\u003e\n\u003cp\u003eWe found that a kidney length that was increased, but within the normal range, was a risk factor for the non-resolution of UTD 3 years after birth. Increased kidney length greater than the normal range indicates nephromegaly in kidney tumors, renal artery stenosis, and compensatory hypertrophy with an isolated kidney, which is due to pathophysiology involving damage and degeneration of the kidney parenchyma and interstitium.\u003csup\u003e16-21\u003c/sup\u003e Moreover, studies have shown a significant correlation between increased maximum longitudinal diameters using US scans and renal scarring on 99 mTc-dimercaptosuccinic acid scintigraphy.\u003csup\u003e27,28\u003c/sup\u003e The authors argued that the pathological consequences of parenchymal scarring represent sonographically increased kidney\u0026nbsp;length, reflecting\u0026nbsp;enlargement of the kidney.\u0026nbsp;In cases of mild UTD, even when there is no improvement in kidney pelvic dilation, they are not likely to have histological changes in the kidney parenchyma and interstitium. Maintaining normal kidney function while showing no differences in markers of urine β2MG reflecting interstitial damage may also support this possibility. Kidneys with mild UTD do not show abnormal US findings other than kidney pelvic dilation. Generally, the technique of measurement for kidney length has been the basis of radiological quantification of kidney development.\u003csup\u003e29\u003c/sup\u003e If the findings of\u0026nbsp;kidney\u0026nbsp;US are outside of the normal range along with the body’s growth, the identification of CAKUT, which was previously undetectable through conventional imaging studies, is possible. In our study, a\u0026nbsp;kidney\u0026nbsp;length \u0026gt;\u0026nbsp;1.2 SDs at 6 months\u0026nbsp;was within the normal range, and abnormal findings were limited to\u0026nbsp;dilation of the kidney pelvis. In mild UTD, patients showing irreversible changes associated with kidney pelvic dilation can show kidney length values close to the upper limit even within the normal range.\u003c/p\u003e\n\u003cp\u003eIn pediatric patients with severe UTD including UPJO, the primary goal is to prevent renal histological damage. Research on this condition has focused on factors contributing to surgical indications and a decline in kidney function.\u003csup\u003e4\u003c/sup\u003e The pathophysiology of severe UTD is presumed to reflect renal parenchymal or interstitial damage associated with elevated intrapelvic pressure and renal reflux. Additionally, heterogeneous biomarkers, such as urine β2MG and NGAL, have been identified as contributing factors to this condition.\u003csup\u003e12-14\u003c/sup\u003e In this study, urine β2MG was not found to be associated with the outcomes of mild UTD. Patients with mild UTD do not have renal histological damage or biomarker changes unless complicated by febrile urinary tract infections or exacerbation of UTD. In addition to urinary β2MG, we analyzed plasma renin and aldosterone activity as components of the RAAS, which plays a crucial role in renal genesis.\u003csup\u003e30\u003c/sup\u003e Comparison to the non-resolution group of children with mild\u0026nbsp;UTD\u0026nbsp;in the right kidney, plasma aldosterone activity at 6 months in the resolution group was significantly higher. While markers of RAAS measured in early in life could predict the need for surgery in patients with obstructive CAKUT,\u003csup\u003e15\u003c/sup\u003e our results of plasma aldosterone activity were associated with the resolution of mild\u0026nbsp;UTD. We were unable to analyze above result in this study, and further functional studies will be necessary in the future.\u0026nbsp;Matsui et al. conducted studies on recurrence after spontaneous resolution of mild UTD, and found that long-term follow-up was unnecessary.\u003csup\u003e31\u003c/sup\u003e There was a report of mild UTD worsening after temporary resolution, even 5–9 years later, but this was an extremely rare occurrence.\u003csup\u003e11\u003c/sup\u003e When exacerbation of UTD occurs, it often presents with symptoms, such as abdominal pain, vomiting, and gross hematuria.\u003csup\u003e31\u003c/sup\u003e Based on opinions emphasizing the importance of reevaluation at the time of symptom appearance or the importance of long-term periodic follow-up, there is no clear consensus on the appropriate management for follow-up of pediatric mild UTD. In our study, sonographically increased kidney length within the normal range was a factor related to non-resolution of kidney pelvic dilation, suggesting that it is important in the management of children with mild UTD.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis study has several limitations. First, the number of included children was small. Second,\u0026nbsp;most cases of UTD requiring surgery occur in children aged 3–4 years or younger, and the estimated period in this study was set at 3 years.\u003csup\u003e32\u003c/sup\u003e Worsening of UTD and the occurrence of urinary tract infections in pediatric patients with mild UTD are critical factors, and focusing on these factors as primary outcomes is desirable. There were no cases of worsening UTD and only three cases of urinary tract infections in our 3-year study. However, as long as mild UTD persists, the potential for the risk of these critical outcomes occurring in the future remains. Third, VCUG was not performed as part of the evaluation for mild UTD, so it is possible that mild VUR may have been present among the causes of UTD in the study population.\u003c/p\u003e\n\u003cp\u003eIn conclusion, this study suggests that an increased sonographic kidney length in UTD P2 with mild UTD is a prognostic factor for non-resolution of kidney pelvic dilatation. The identification of factors for non-resolution could be useful for long-term follow-up.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors report no conflicts of interest relevant to this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur study received no specific grant from any funding agency in the public, commercial, or not-for-profit sections.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll procedures performed in this study involving human participants were in accordance with the ethical standards of the Kakogawa Central City Hospital Ethics Board. The study was conducted (approval number: 25-19) in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consent was obtained from all patients\u0026rsquo; parents for this study according to institutional ethics.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate/consent to publish\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBefore enrollment, written informed consent was obtained from all patients and their parents for this study in accordance with guidelines.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eS.I. prepared the manuscript. S.I. and J.F. collected the clinical data. A.N., T.M. revised the article. All the authors have read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Ellen Knapp, PhD, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData from this study can be obtained from the corresponding authors at reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBlyth B, Snyder HM, Duckett JW (1993) Antenatal diagnosis and subsequent management of hydronephrosis. J Urol 149: 693-698. https://doi.org/10.1016/s0022-5347(17)36185-2\u003c/li\u003e\n\u003cli\u003eMallik M, Watson AR (2008) Antenatally detected urinary tract abnormalities: more detection but less action. Pediatr Nephrol 23: 897-904. https://doi.org/10.1007/s00467-008-0746-9\u003c/li\u003e\n\u003cli\u003eHerthelius M (2023) Antenatally detected urinary tract dilatation: long-term outcome. Pediatr Nephrol 38: 3221-3227. https://doi: 10.1007/s00467-023-05907-z\u003c/li\u003e\n\u003cli\u003eOnen A (2007) An alternative grading system to refine the criteria for severity of hydronephrosis and optimal treatment guideline in nepnates with primary UPJ-type hydronephrosis. J Pediatr Urol 3: 200-205. https://doi.org/10.1016/j.jpurol.2006.08.002\u003c/li\u003e\n\u003cli\u003eBarbosa JA, Chow JS, Benson CB, Yorioka MA, Bull AS, Retik AB, Nguyen HT (2012) Postnatal longitudinal evaluation of children diagnosed with prenatal hydronephrosis: insights in natural history and referral pattern. Prenat Diagn 32: 1242-1249. https://doi.org/10.1002/pd.3989\u003c/li\u003e\n\u003cli\u003eYang Y, Hou Y, Niu ZB, Wang CL (2010) Long-term follow-up and management of prenatally detected, isolated hydronephrosis. J Pediatr Surg 45: 1701-1706. https://doi.org/ 10.1016/j.jpedsurg.2010.03.030.\u003c/li\u003e\n\u003cli\u003ePasserotti CC, Kalish LA, Chow J, Passerotti AM, Recabal P, Cendron M, Lee RS, Lopez AB, Retik AB, Nguyen HT (2011) The predictive value of the first postnatal ultrasound in children with antenatal hydronephrosis. J Pediatr Urol 7: 128-136. https://doi.org/10.1016/j.jpurol.2010.09.007\u003c/li\u003e\n\u003cli\u003eSidhu G, Beyene J, Rosenblum ND (2006) Outcome of isolated antenatal hydronephrosis: a systematic review and meta-analysis. Pediatr Nephrol 21: 218-224. https://doi.org/10.1007/s00467-005-2100-9\u003c/li\u003e\n\u003cli\u003eHerthelius M, Axelsson R, Lidefelt KJ (2020) Antenatally detected urinary tract dilatation: a 12-15-year follow-up. Pediatr Nephrol 35: 2129-2135. https://doi: 10.1007/s00467-020-04659-4\u003c/li\u003e\n\u003cli\u003eNguyen HT, Herndon CDA, Cooper C, Gatti J, Kirsch A, Kokorowski P, Lee R, Perez-Brayfield M, Metcalfe P, Yerkes E, Cendron, Cambell JB (2010) The society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis. J Pediatr Urol 6; 212-231. https://doi.org/10.1016/j.jpurol.2010.02.205\u003c/li\u003e\n\u003cli\u003eRigas A, Karamanolakis D, Bogdanos I, Stephanidis A, Androulakakis PA (2003) Pelviureteric junction obstruction by crossing renal vessels: clinical and imaging features. BJU Int 92: 101-103. https://doi.org/10.1046/j.1464-410x.2003.04265.x\u003c/li\u003e\n\u003cli\u003ePapachristou F, Pavlaki A, Printza N (2014) Urinary and serum biomarkers in ureteropelvic junction obstruction: a systematic review. Biomarkers 19: 531-540. https://doi.org/10.3109/1354750X.2014.943292\u003c/li\u003e\n\u003cli\u003eMadsen MG, N\u0026oslash;rregaard R, Palmfeldt J, Olsen LH, Fr\u0026oslash;ki\u0026aelig;r J, J\u0026oslash;rgensen TM (2013) Epidermal growth factor and monocyte chemotactic peptide-1: potential biomarkers of urinary tract obstruction in children with hydronephrosis. J Pediatr Urol 9: 838-845. https://doi.org/10.1016/j.jpurol.2012.11.011\u003c/li\u003e\n\u003cli\u003eCost NG, Noh PH, Devarajan P, Ivancic V, Reddy PP, Minevich E, Bennett M, Haffner C, Schulte M, DeFoor Jr WR (2013) Urinary NGAL levels correlate with differential renal function in patients with ureteropelvic junction obstruction undergoing pyeloplasty. J Urol 190: 1462-1467. https://doi.org/10.1016/j.juro.2013.05.003\u003c/li\u003e\n\u003cli\u003eMarzuillo P, Palma PL, Sessa AD, Roberti A, Torino G, De Lucia M, Del Giudice EM, Guarino S, Di Lorio G (2023) Early-in-Life Serum Aldosterone Levels Could Predict Surgery in Patients with Obstructive Congenital Anomalies of the Kidney and Urinary Tract: A Pilot Study. J Clin Med 12: 1921. https://doi: 10.3390/jcm12051921.\u003c/li\u003e\n\u003cli\u003eShaikh N, Ewing AL, Bhatnagar S, Hoberman A (2010) Risk of renal scarring in children with a first urinary tract infection: a systematic review. Pediatrics 126: 1084-1091. https://doi.org/10.1542/peds.2010-0685\u003c/li\u003e\n\u003cli\u003eWennerstrom M, Hansson S, Jodal U, Stokland E (2000) Primary and acquired renal scarring in boys and girls with urinary tract infection. J Pediatr 136: 30-34. https://doi.org/10.1016/s0022-3476(00)90045-3\u003c/li\u003e\n\u003cli\u003eSaxena AB, Busque S, Arjane P, Myers BD, Tan JC (2004) Preoperative renal volumes as a predictor of graft function in living donor transplantation. Am J Kidney Dis 44: 877-885.\u003c/li\u003e\n\u003cli\u003eZumrutdal AO, Turan C, Cetin F, Adanali S (2002) Relationship between renal size and hypertension in patients with chronic renal failure. Nephron 90: 145-147. https://doi.org/10.1159/000049034\u003c/li\u003e\n\u003cli\u003eGandy SJ, Armoogum K, Nicholas RS, McLeay TB, Houston JG (2007) A clinical MRI investigation of the relationship between kidney volume measurements and renal function in patients with renovascular disease. Br J Radiol 80: 12-20. https://doi.org/10.1259/bjr/11148990\u003c/li\u003e\n\u003cli\u003eTroell S, Berg U, Johansson B, Wikstad I (1984) Ultrasonographic renal parenchymal volume related to kidney function and renal parenchymal area in children with recurrent Gatti JM, Broecker BH, Scherz HC, Perez-Brayfield M, Kirsch AJ (2001) Antenatal hydronephrosis with postnatal resolution: how long are postnatal studies warranted? Urology 57: 1178. https://doi.org/10.1016/s0090-4295(00)00933-xhttps://doi.org/10.1177/028418518402500512\u003c/li\u003e\n\u003cli\u003eGatti JM, Broecker BH, Scherz HC, Perez-Brayfield M, Kirsch AJ (2001) Antenatal hydronephrosis with postnatal resolution: how long are postnatal studies warranted? Urology 57: 1178. https://doi.org/10.1016/s0090-4295(00)00933-x\u003c/li\u003e\n\u003cli\u003eNguyen HT, Benson CB, Bromley B, Cambell JB, Chow J, Coleman B, Cooper C, Crino J, Darge K, Herndon CDA, Odibo AO, Somers MJG, Stein DR (2014) Multidisciplinary consensus on the classification of prenatal and postnatal urinary tract dilation (UTD classification system). J Pediatr Urol 10:982-998. https://doi: 10.1016/j.jpurol.2014.10.002.\u003c/li\u003e\n\u003cli\u003eFujita N, Uemura O, Harada R,Matsumura C, Sakai T, Hamasaki Y, Kamei K, Nishi K, Kaneko T, Ishikura K, Gotoh Y; the pediatric CKD Study Group in Japan in conjunction with the Committee of Measures for Pediatric CKD of the Japanese Society of Pediatric Nephrology (2022) Ultrasonographic reference values and a simple yet practical formula for estimating average kidney length in Japanese children. Clin Exp Nephrol 26: 808-818. https://doi.org/10.1007/s10157-022-02205-0\u003c/li\u003e\n\u003cli\u003eDinkel E, Ertel M, Dittrich M, Peters H, Berres M, Schulte-Wissermann H (1985) Kidney size in childhood sonographical growth charts for kidney length and volume. Pediatr Radiol 15: 38-43. https://doi.org/10.1007/BF02387851\u003c/li\u003e\n\u003cli\u003eAksu N, Yavascan O, Kangin M, Kara OD, Aydin Y, Erdogan H, Tuncel TC, Cetinkaya E, Ozbay E, Sandikcioglu (2005). Postnatal management of infants with antenatally detected hydronephrosis. Pediatr Nephrol 20: 1253-1259. https://doi: 10.1007/s00467-005-1989-3. Epub 2005 Jul 16.\u003c/li\u003e\n\u003cli\u003ePeratoner L, Pennesi M, Bordugo A, Melega R, Sorce P, Travan L, Minisini S, Zennaro F, Ronch LD (2005) Kidney length and scarring in children with urinary tract infection: importance of ultrasound scans. Abdom Imaging 30: 780-785. https://doi.org/10.1007/s00261-005-0324-6\u003c/li\u003e\n\u003cli\u003eBouissou F, Munzer C, Decramer S, Rousse B, Novo R, Morin D, Lavocat MP, Guyot C, Taque S, Fischbach M, Ouhayoun E; French Society of Nuclear Medicine and Moleculat Imaging: Loirat C; French Society of Pediatric Nephrology (2008) Prospective randomized trial comparing short and long intravenous antibiotic treatment of acute pyelonephritis in children: dimercaptosuccinic acid scintigraphic evaluation at 9 months. Pediatrics 121: e553-560. https://doi.org/10.1542/peds.2006-3632\u003c/li\u003e\n\u003cli\u003eKlare B, Geiselhardt B, Wesch H, Scharer K, Immich H, Willich E (1980) Radiological kidney size in childhood. Pediatr Radiol 9: 153-160. https://doi.org/10.1007/BF01464310\u003c/li\u003e\n\u003cli\u003eYosypiv IV (1996) Activation of angiotensin0generating systems in the developing kidney. Hypertension 2: 281-286. https://doi.org/10.1161/01.hyp.27.2.281\u003c/li\u003e\n\u003cli\u003eMatsui F, Shimada K, Matsumoto F, Takano S (2008) Late recurrence of symptomatic hydronephrosis in patients with prenatally detected hydronephrosis and spontaneous improvement. J Urol 180: 322-325. https://doi.org/10.1016/j.juro.2008.03.065\u003c/li\u003e\n\u003cli\u003eChertin B, Pollack A, Koulikov D, Rabinowitz R, Hain D, Hadas-Halpren I, Farkas A (2006) Conservative treatment of ureteropelvic junction obstruction in children with antenatal diagnosis of hydronephrosis: Lessons learned after 16 years of follow-up. Eur Urol. 49:734-738. https://doi: 10.1016/j.eururo.2006.01.046\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 Comparison of clinical characteristics in each kidney between resolution and non-resolution group\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"567\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 33.3334%;\"\u003e\n \u003cp\u003eChildren with mild UTD\u003cbr\u003e\u0026nbsp;in the right kidney n=25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eChildren with mild UTD\u003cbr\u003e\u0026nbsp;in the left kidney n=33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003eResolution\u003cbr\u003e\u0026nbsp;n=16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003eNon-resolution\u003cbr\u003e\u0026nbsp;n=9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003eResolution\u003cbr\u003e\u0026nbsp;n=21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003eNon-resolution\u003cbr\u003e\u0026nbsp;n=12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eCharacteristics at birth and during neonatal periods\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Boy : Girl\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e11 : 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e6 : 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e13 : 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e9 : 3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Identification in fetal US, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e8 (50.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e7 (77.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e11 (52.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e6 (50.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;APGAR score, 1\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e8 (8-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e8 (7-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e9 (8-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e8 (7-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;APGAR score, 5\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e9 (9-10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e9 (8.5-10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e9 (9-10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e9 (8-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma renin activity (ng/mg/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e15.5 (6.8-40.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e10.5 (5.1-24.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e20.8 (7.6-43.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e12.1 (4.0-24.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma aldosterone activity (pg/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e652 (586-1315)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e700 (458-1300)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e992 (748-1583)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e1130 (781-1190)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum Cr level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.22 (0.15-0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.19 (0.16-0.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.39 (0.27-0.48)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.42 (0.23-0.65)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum LDH level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e257 (228-267)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e226 (187-266)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e390 (283-447)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e353 (316-469)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Urine \u0026beta;2MG/Cr ratio\u0026nbsp;(\u0026mu;g/g・Cr)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e7.4 (4.8-12.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e10.6 (6.7-16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e15.4 (8.2-38.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e14.5 (2.8-29.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eCharacteristics at 1 month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma renin activity (ng/mg/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e15.5 (6.8-40.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e10.5 (5.1-24.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e15.5 (7.9-28.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e14.3 (6.3-26.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma aldosterone activity (pg/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e652 (586-1315)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e700 (458-1300)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e1210 (603-1500)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e652 (516-1140)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum Cr level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.22 (0.15-0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.19 (0.16-0.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.21 (0.17-0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.21 (0.15-0.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum LDH level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e257 (228-267)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e226 (187-266)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e256 (226-271)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e242 (225-262)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Urine \u0026beta;2MG/Cr ratio\u0026nbsp;(\u0026mu;g/g・Cr)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e7.4 (4.8-12.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e10.6 (6.7-16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e7.4 (4.8-16.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e8.1 (3.5-15.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eCharacteristics at 3 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma renin activity (ng/mg/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e14.9 (7.5-30.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e9.7 (4.5-26.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e25.7 (7.2-36.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e13.7 (4.2-20.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma aldosterone activity (pg/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e841 (402-1125)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e424 (314-639)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e829 (409-1220)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e488 (391-889)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum Cr level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.19 (0.16-0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.16 (0.14-0.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.19 (0.16-0.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.17 (0.14-0.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum LDH level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e254 (237-283)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e227 (205-259)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e254 (234-284)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e246 (225-264)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Urine \u0026beta;2MG/Cr ratio\u0026nbsp;(\u0026mu;g/g・Cr)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.91 (0.62-1.34)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.87 (0.80-1.66)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.91 (0.58-1.70)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.85 (0.75-1.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eCharacteristics at 6 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Systolic blood pressure (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e93 (82-104)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e100 (74-104)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e91 (80-100) *\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e100 (96-106) *\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma renin activity (ng/mg/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e16.0 (6.7-50.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e16.4 (5.8-24.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e16.4 (6.0-40.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e16.0 (5.7-34.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma aldosterone activity (pg/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e934 (440-2130) *\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e435 (199-690) *\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e584 (296-1400)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e672 (240-1170)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum Cr level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.19 (0.17-0.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.17 (0.14-0.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.12 (0.17-0.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.18 (0.14-0.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum LDH level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e267 (243-338)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e254 (243-337)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e266 (244-322)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e272 (249-316)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Urine \u0026beta;2MG/Cr ratio\u0026nbsp;(\u0026mu;g/g・Cr)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.46 (0.36-1.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.41 (0.37-0.81)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.42 (0.34-0.74)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.53 (0.41-0.89)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eCharacteristics at 1 year\u003csup\u003e‖\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Systolic blood pressure (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e94 (83-103)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e106 (100-112)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e99 (88-111)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e99 (92-105)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma renin activity (ng/mg/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e12.5 (4.5-33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e10.6 (8.5-13.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e14.3 (5.7-24.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e11.7 (10.5-16.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma aldosterone activity (pg/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e288 (213-700)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e381 (200-529)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e373 (150-547)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e233 (144-439)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum Cr level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.20 (0.18-0.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.20 (0.17-0.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.20 (0.19-0.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.20 (0.17-0.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum LDH level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e273 (236-320)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e273 (231-309)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e274 (237-316)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e273 (256-308)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Urine \u0026beta;2MG/Cr ratio\u0026nbsp;(\u0026mu;g/g・Cr)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.65 (0.32-0.93)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.29 (0.21-0.54)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.43 (0.27-0.65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.55 (0.27-0.96)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eCharacteristics at 2 years\u003csup\u003e\u0026para;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Systolic blood pressure (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e97 (94-111)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e110 (94-121)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e97 (88-109)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e101 (96-109)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma renin activity (ng/mg/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e7.5 (6.3-22.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e5.2 (3.4-21.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e8.7 (4.2-21.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e6.8 (5.5-10.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma aldosterone activity (pg/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e165 (108-319)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e197 (165-280)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e180 (112-180)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e175 (120-254)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum Cr level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.22 (0.17-0.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.20 (0.19-0.26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.24 (0.20-0.26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.22 (0.18-0.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum LDH level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e255 (213-280)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e256 (226-281)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e256 (224-266)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e259 (234-279)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Urine \u0026beta;2MG/Cr ratio\u0026nbsp;(\u0026mu;g/g・Cr)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.24 (0.19-0.70)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.31 (0.29-0.41)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.30 (0.23-0.43)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.31 (0.24-0.40)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003eCharacteristics at 3 years\u003csup\u003e\u0026para;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Systolic blood pressure (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e99 (90-115)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e99 (93-113)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e99 (92-105)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e95 (86-113)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma renin activity (ng/mg/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e5.9 (3.1-8.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e7.8 (4.3-13.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e7.8 (4.4-11.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e4.4 (3.4-10.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Plasma aldosterone activity (pg/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e129 (44-234)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e139 (61-153)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e142 (61-259)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e134 (108-185)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum Cr level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.27 (0.21-0.30)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.24 (0.23-0.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.27 (0.24-0.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.24 (0.23-0.30)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Serum LDH level (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e231 (194-263)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e235 (210-270)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e232 (195-276)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e246 (213-265)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;Urine \u0026beta;2MG/Cr ratio\u0026nbsp;(\u0026mu;g/g・Cr)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7549%;\"\u003e\n \u003cp\u003e0.22 (0.14-0.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5786%;\"\u003e\n \u003cp\u003e0.24 (0.19-0.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.7547%;\"\u003e\n \u003cp\u003e0.23 (0.16-0.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16.5785%;\"\u003e\n \u003cp\u003e0.26 (0.22-0.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" style=\"width: 100%;\"\u003e\n \u003cp\u003eUTD; urinary tract dilatation, US; ultrasound, Cr; creatinine, \u0026beta;2MG;\u0026nbsp;\u0026beta;2 microglobulin,*; p\u0026lt;0.05,\u0026nbsp;\u0026dagger;;\u0026nbsp;estimated in 29 neonates, \u0026Dagger;; estimated in 29 neonates, ‖;estimated in 28 children, \u0026para;; estimated in 21 children,\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 2 Comparison of kidney ultrasound of urinary tract dilatation P2 between the resolution and non-resolution groups.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"573\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 337px;\"\u003e\n \u003cp\u003eUTD P2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003eResolution\u003cbr\u003e\u0026nbsp;n=16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003eNon-resolution\u003cbr\u003e\u0026nbsp;n=19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp;Characteristics at birth\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e44.4 (41.5-46.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e46.4 (44.0-53.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e-1.08 (-1.67-0.81)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e-0.73 (-1.16-0.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Volume of kidney (ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e11.0 (9.1-13.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e12.4 (9.5-13.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp;Characteristics at 1month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e49.5 (46.3-51.1)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e52.7 (48.5-55.7)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e-0.02 (-0.79-0.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e-0.66 (-0.33-1.06)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Volume of kidney (ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e14.9 (11.5-17.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e17.4 (14.5-23.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp;Characteristics at 3 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e52.9 (50.1-55.1)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e58.1 (56.5-59.8)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e0.53 (-0.24-1.13)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e1.13 (0.74-2.03)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Volume of kidney (ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e19.1 (14.5-19.8)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e26.3 (21.3-29.3)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp;Characteristics at 6 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e56.5 (53.3-59.8)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e62.3 (59.3-65.0)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e0.45 (-0.13-1.06)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e1.69 (0.86-2.10)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Volume of kidney (ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e22.0 (18.9-24.1)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e24.8 (20.0-31.5)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp;Characteristics at 1 year\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e57.7 (56.0-60.3)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e62.5 (60.8-68.5)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Length of kidney (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e0.05 (-0.42-0.36)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e0.87 (0.57-1.67)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 236px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Volume of kidney (ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 175px;\"\u003e\n \u003cp\u003e22.7 (17.9-29.2)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e29.3 (25.2-38.9)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" style=\"width: 573px;\"\u003e\n \u003cp\u003eUTD; urinary tract dilatation, SD; Standard deviation, *; p\u0026lt;0.05, \u0026dagger;; estimated in 33 kidney including 15 of resolution and 18 of non-resolution\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"pediatric-nephrology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pnep","sideBox":"Learn more about [Pediatric Nephrology](http://link.springer.com/journal/467)","snPcode":"467","submissionUrl":"https://www.editorialmanager.com/pnep/default2.aspx","title":"Pediatric Nephrology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Children, Increased kidney length, Mild urinary tract dilatation, Kidney sonography, Resolution","lastPublishedDoi":"10.21203/rs.3.rs-5319229/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5319229/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eEven asymptomatic and mild urinary tract dilatation (UTD) that does not resolve may harbor the potential for progression of the severity of UTD, which suggests the need for continued observation. However, no studies have investigated factors contributing to the persistence or non-resolution of mild UTD.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e \u003cp\u003eWe conducted a prospective cohort study of children who were newly diagnosed with mild UTD during the neonatal period from 2013 to 2021. They were evaluated by periodic kidney ultrasound until 3 years old. Sonographic reference values of kidney length were evaluated according to estimation formulas, and sonographic kidney volume was calculated using kidney length, width, and depth.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThis study included 33 children with mild UTD, which involved 58 kidney units. These units were graded as UTD P1 in 23 and UTD P2 in 35 units. Sonographic kidney length and volume were significantly higher in kidneys with UTD P2 that did not resolve during 3 years than in those that resolved at 3, 6 months and 1 year. The time to resolution of UTD P2 in kidneys with a length\u0026thinsp;\u0026gt;\u0026thinsp;0.7 standard deviations at 3 months and \u0026gt;\u0026thinsp;1.2 standard deviations at 6 months was significantly longer than that in kidneys with a length\u0026thinsp;\u0026le;\u0026thinsp;0.7 standard deviations at 3 months (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01) and \u0026le;\u0026thinsp;1.2 standard deviations at 6months (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eIncreased sonographic kidney length in UTD P2 is a prognostic factor for non-resolution of kidney pelvic dilatation.\u003c/p\u003e\u003ch2\u003eTrial Registration\u003c/h2\u003e \u003cp\u003eUMIN Clinical Trial Registry: UMIN 000013286 (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000015493\u003c/span\u003e\u003cspan address=\"https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000015493\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e), with the registration date of February 26, 2014.\u003c/p\u003e","manuscriptTitle":"Increased kidney length in mild urinary tract dilatation is a significant prognostic factor for non-resolution","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-28 06:41:04","doi":"10.21203/rs.3.rs-5319229/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revisions Needed","date":"2024-11-18T11:40:57+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-10-24T06:52:20+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-10-23T18:28:56+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-10-23T15:52:23+00:00","index":"","fulltext":""},{"type":"submitted","content":"Pediatric Nephrology","date":"2024-10-23T09:15:32+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"pediatric-nephrology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pnep","sideBox":"Learn more about [Pediatric Nephrology](http://link.springer.com/journal/467)","snPcode":"467","submissionUrl":"https://www.editorialmanager.com/pnep/default2.aspx","title":"Pediatric Nephrology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"1d33f2db-7d2e-45a4-949b-13a36800317d","owner":[],"postedDate":"October 28th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-03-10T19:50:23+00:00","versionOfRecord":{"articleIdentity":"rs-5319229","link":"https://doi.org/10.1007/s00467-025-06733-1","journal":{"identity":"pediatric-nephrology","isVorOnly":false,"title":"Pediatric Nephrology"},"publishedOn":"2025-03-07 15:58:44","publishedOnDateReadable":"March 7th, 2025"},"versionCreatedAt":"2024-10-28 06:41:04","video":"","vorDoi":"10.1007/s00467-025-06733-1","vorDoiUrl":"https://doi.org/10.1007/s00467-025-06733-1","workflowStages":[]},"version":"v1","identity":"rs-5319229","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5319229","identity":"rs-5319229","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}