Paediatric Multicystic Dysplastic Kidney Disease in Cape Town, South Africa

Paediatric Multicystic Dysplastic Kidney Disease in Cape Town, South Africa | 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 Paediatric Multicystic Dysplastic Kidney Disease in Cape Town, South Africa Datonye Christopher Briggs, Khanyisile Hlongwa, Mignon McCulloch, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7706913/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Nov, 2025 Read the published version in BMC Nephrology → Version 1 posted 14 You are reading this latest preprint version Abstract Introduction: Multicystic dysplastic kidney disease (MCDK) is a notable congenital anomaly of the kidney and urinary tract, with potential risk for chronic kidney disease, yet data from sub-Saharan Africa remain scarce. This study examined the pattern of MCDK, associated contralateral kidney abnormalities, determined the predictors of MCDK involution and assessed short-term outcomes in children followed beyond one year. Method This retrospective study involved children under 13 years of age with suspected unilateral MCDK, confirmed on kidney ultrasound and [ 99m Tc]Tc-MAG3 scans at the Red Cross War Memorial Children's Hospital between January 1, 2014, and December 31, 2023. Demographic, clinical, and radiologic data were obtained. The Log-rank test and Cox Proportional Hazards regression analyses were used to identify predictors of MCDK involution. Ethical approval (HREC REF: 805/2024). Results Among 1,581 new cases, 98 (6.2%) had unilateral MCDK. Fifty percent were male, and 57.1% had left-sided involvement. Median follow-up was 36 months (IQR: 12–72). Contralateral kidney abnormalities occurred in 17 (17.3%), most commonly duplex kidney (33.3%) and ureteropelvic junction obstruction (27.8%), but no vesicoureteric reflux was noted. Of 81 children followed beyond a year, 80.2% demonstrated contralateral hypertrophy, and 69.1% exhibited involution of the affected kidney. Initial kidney size ≤ 5.0cm was the sole predictor of involution (HR: 2.42, 95% CI: 1.31–4.48). Urinary tract infections occurred in (18.5%), proteinuria in (2.5%), hypertension (1.2%) and 2.5% developed chronic kidney disease related to contralateral dysplasia. One nephrectomy was performed, and no malignancies or deaths. At last follow-up, 12.3% had transitioned to adolescent clinics. Conclusion All MCDK cases were unilateral, with duplex kidney being the most common contralateral abnormality, a distinctive finding in our cohort. Follow-up into adolescence may be beneficial, as progression of chronic kidney disease is rare in those without contralateral anomalies. Multicentre long-term studies are needed to provide standardised follow-up guidelines. Chronic Kidney Disease Multicystic Dysplastic Kidney Paediatrics Epidemiology Solitary Kidney Figures Figure 1 Figure 2 Figure 3 Take-home messages In children with MCDK, conservative management is sufficient, and there is no need for nephrectomy. Frequency of kidney ultrasound scan monitoring at birth, 1 month, 2 years, 5 years, and 10 years (depending on resource availability) is a suggested approach. A yearly follow-up kidney health assessment – including blood pressure and urine dipstick checks, with reassessments every one or two years, is a reasonable approach. Introduction Multicystic dysplastic kidney disease (MCDK) is a significant congenital anomaly of kidney development, characterised by multiple non-communicating cysts of varying sizes within a non-functioning parenchyma [1]. This genitourinary malformation is frequently identified in utero or during the early neonatal period, with an incidence of approximately 1 in 2,200 to 4,300 live births [2,3]. MCDK arises from defective and incomplete nephron formation resulting from maldevelopment of the ureteric bud during early kidney morphogenesis [4]. It is one of the leading causes of a palpable abdominal mass in infants, second only to hydronephrosis due to ureteropelvic junction obstruction (UPJO). 4 While MCDK typically affects a single kidney, bilateral involvement is rare but invariably fatal, as it is associated with kidney failure and pulmonary hypoplasia [4]. Studies suggest that involution of the multicystic dysplastic kidney is most pronounced within the first two to three years of life [5,6], with approximately 10% occurring by the first year, 35.0% by the second year, and between 38.5% and 47% by the fifth year [4,7]. Nonetheless, concerns persist regarding an elevated risk of kidney failure in children with MCDK, particularly among those lacking compensatory hypertrophy of the contralateral kidney[5] Furthermore, up to one-third of affected children may exhibit abnormalities in the solitary functioning contralateral kidney [3], such as vesicoureteral reflux (VUR)[8], ureteropelvic junction obstruction, dysplasia, or positional anomalies, all of which increase the risk of chronic kidney disease [9–11]. Although less frequently reported, hypertension develops in 3.2% of cases [12], urinary tract infections in 5.0%–34.7% [13–16], and malignant transformation in 0.07% [12]. The epidemiology and outcomes of paediatric MCDK in sub-Saharan Africa remain largely underreported. The existing literature is predominantly limited to case reports or small-scale studies [17–20], which hinders a comprehensive understanding of MCDK in this setting. Furthermore, an important aspect of MCDK management is determining the appropriate frequency of ultrasonographic surveillance, which currently lacks standardisation [21,22]. A recent Canadian study recommended scheduled ultrasounds for children with congenital solitary kidney, including MCDK, at specific intervals (birth, 6 months, 2, 5, 10, and 15 years) to minimise unnecessary imaging and optimise resource utilisation [23]; however, it remains unclear what occurs in Africa. Therefore, this study sought to address these gaps by sharing our experience among children with MCDK seen at a tertiary paediatric specialist hospital in sub-Saharan Africa. Methods This retrospective study evaluated all children (< 13 years) diagnosed with MCDK by either antenatal or postnatal abdominopelvic ultrasound, for whom a corresponding confirmatory Mercaptotriglycine ([ 99m Tc]Tc-MAG3) scan was performed at the Red Cross War Memorial Children’s Hospital (RCWMCH) in Cape Town, South Africa, over ten years from 1st January 2014 to 31st December 2023. At the RCWMCH, children presenting with suspected MCDK, dysplastic cystic kidneys, unilateral renal agenesis, abdominal masses, hydronephrosis, suspected or confirmed urinary tract infection are typically referred for specialist follow-up in the paediatric nephrology clinic. Following an initial or repeat kidney ultrasound, conducted shortly after birth or within the first month of life, a confirmatory [ 99m Tc]Tc-MAG3 scan is routinely performed within six to eight weeks, in accordance with current standards of care, to differentiate dysplastic kidneys with preserved function from solitary functioning kidneys. Diagnosis of MCDK was based on expanded kidney ultrasound radiological criteria [24], with confirmation of non-functionality established by a [ 99m Tc]Tc-MAG3 scan demonstrating a differential kidney function of zero percent. In confirmed cases, serial ultrasound examinations are scheduled at birth, and then at 3, 6, 12, 24, 60, and 120 months. This is done to monitor involution of the MCDK and to assess growth or anomalies of the contralateral kidney. Repeat [ 99m Tc]Tc-MAG3 diuretic scans are reserved for patients exhibiting worsening contralateral hydronephrosis or recurrent urinary tract infections. Surgical intervention is rarely indicated and typically considered only if the dysplastic kidney exceeds 5 cm and increases in size to cause abdominal symptoms, or in cases of recurrent urinary tract infections, unexplained hypertension, or suspected malignancy. All kidney ultrasound and nuclear medicine scan records are systematically archived in the Picture Archiving and Communication Systems (PACS) and Venus Share Archiving communications system, facilitating digital storage, straightforward retrieval, and comparative referencing with earlier imaging studies. Definition of terms: Vesicoureteral reflux (VUR ) staging on MCUG was classified according to the International Reflux Study Committee Classification [25]. Ureteropelvic junction obstruction (UPJO) was defined as the absence of ureter dilatation despite the kidney pelvis exceeding 10–15 mm, calyceal dilatation and an abnormal diuretic renogram pattern. A duplex system was defined as a single kidney unit drained by two collecting systems [26]. A unilateral MCDK without genitourinary abnormalities in the bladder or contralateral kidney is a simple MCDK , and a unilateral MCDK with genitourinary abnormalities is a complex MCDK [19]. Complete involution refers to the absence of MCDK evident on the kidney ultrasound. The age at which MCDK becomes undetectable is recognised as the time of complete involution [4]. Partial involution indicates a decrease in the size of MCDK, as demonstrated by previous serial kidney ultrasound assessments [4]. Compensatory hypertrophy of the contralateral kidney was defined as having a bipolar diameter exceeding two standard deviations above the age-appropriate mean of a normal kidney. In contrast, the absence of hypertrophy in the contralateral kidney was indicated by measurements that fall one standard deviation below the mean value of a normal kidney for the corresponding age [27]. Urinary Tract Infection (UTI) was characterised by the presence of pyuria (≥ 5 white blood cells per high-power field) and/or a positive leukocyte esterase test or nitrite, along with a positive urine culture. A UTI was diagnosed if a suprapubic bladder aspiration reveals growth of a single bacterium > 10 3 or if a midstream clean-void urine sample shows ≥ 10 5 colony-forming units/ml in toilet-trained children. Additionally, growth of ≥ 5 × 10 4 colony-forming units/mL from a transurethral catheterised specimen was also considered a UTI [15]. An uncomplicated duplex kidney has two renal moieties with a different pelvicalyceal system, and a complicated duplex kidney is one with incomplete duplication, obstructed drainage from a ureterocoele, hydronephrosis, reflux, dysplasia or reduced function [28]. Hypertension : systolic and/or diastolic blood pressure greater than or equal to the 95th percentile (adjusted for age, gender and height) on at least three different occasions [29]. Estimated glomerular filtration rate (eGFR) : The modified bedside Schwartz method was used with the measured height(cm) and serum creatinine [30]. Proteinuria : protein creatinine ratio (g/g) on a spot urine sample > 0.20 in children over two years of age and > 0.50 in infants and toddlers aged 6 to 24 months [31]. Chronic kidney disease (CKD) was staged according to KDIGO classification using the eGFR: stage 1 (> 90 ml/min/1.73 m 2 with renal parenchymal damage), stage 2 (90–60 ml/min/1.73 m 2 ), stage 3 (60–30 ml/min/1.73 m 2 ), stage 4 (30–15 ml/min/1.73 m 2 ), or stage 5 (< 15 ml/min/1.73 m 2 ) [32]. A child was considered lost to follow-up (LTFU) after having consecutively missed at least two years of scheduled follow-up appointments. undefined Data Collection and flow of eligible children through the study : A comprehensive sampling frame included all eligible children who underwent both [ 99m Tc]Tc-MAG3 and kidney ultrasound scans during the study period, identified from institutional databases. Data were systematically extracted using a standardised proforma from case notes, clinician request forms, and scan reports. The following variables were collected: patient demographic and anthropometric details at the time of MCDK diagnosis; indication and timing of both KUB and [99mTc]Tc-MAG3 scans; physical examination findings; and serum creatinine levels, where available. Each KUB scan report was reviewed to document the type of MCDK, affected kidney size (mm), number of cysts, anteroposterior diameter (APD), as well as the size (mm), corticomedullary differentiation (CMD), and the presence of a visible ureter in the unaffected kidney. Correspondingly, [ 99m Tc]Tc-MAG3 reports were scrutinised for differential function in each kidney, evidence of obstruction, and confirmation or exclusion of MCDK non-functionality. Additional data were extracted regarding findings from micturating cystourethrograms (MCUG), which were performed typically following the presence of upper tract dilatation on ultrasound scan or reflux suggested on [ 99m Tc]Tc-MAG3. The presence of concomitant renal or extra-renal anomalies, as well as complications such as hypertension, recurrent urinary tract infections, or malignant transformation, was also recorded. Clinical outcomes were documented, including involution status (complete or partial), kidney function (if recorded during or at the last follow-up visit), management approach (conservative or surgical), requirement for kidney supportive therapy, and final status (ongoing follow-up, transition to adolescent/adult care, loss to follow-up, or death). Data were analysed using IBM SPSS version 30.0.0. Normality of the collated data was assessed, with continuous variables summarised as means and standard deviations for normally distributed data, or as medians and interquartile ranges (IQR) otherwise; trends were illustrated using line graphs. Categorical variables were presented using frequency tables and charts. Eighteen children who underwent baseline KUB and [ 99m Tc]Tc-MAG3 imaging within their first year of life but lacked at least one year of subsequent follow-up were excluded from longitudinal analyses, and missing data were appropriately addressed. Predictors of MCDK involution were initially explored using the Log Rank (Mantel-Cox) test in bivariate analysis, followed by Cox proportional hazards regression. Cases without evidence of MCDK involution at the end of follow-up were right-censored. In the multivariate regression, 'MCDK involuted' served as the status (dependent) variable and 'year of involution' as the time variable. Predictor variables included initial size of the multicystic dysplastic kidney ( 5 cm), type of MCDK (simple vs complex), gender, presence of contralateral hypertrophy, presence of contralateral abnormality, and laterality; all were entered as categorical covariates in the Cox model using the 'Enter' method. Statistical significance was set at p < 0.05. Data were stored in a password-protected Excel file accessible only to the primary researcher, with the patient identification key maintained separately to ensure confidentiality. Each participant was assigned a unique study number, and no identifying information was included in any research outputs. Results Incidence of MCDK among children seen in the renal clinic of RCWMCH: Between 1 January 2014 and 31 December 2023, there were 20,569 paediatric renal outpatient clinic visits, including 1,581 new cases. Of these, 101 children were diagnosed with multicystic dysplastic kidney (MCDK) based on postnatal KUB and [ 99m Tc]Tc-MAG3 scans; three cases were excluded due to unavailable records, resulting in 98 confirmed cases with an MCDK incidence of 6.2%. The incidence varied annually, with the lowest rate of 1.5% observed in 2020 and the highest of 10.1% in 2022, as depicted in Fig. 1 . Demographic characteristics of study participants (Table ) Of the 98 children diagnosed with unilateral MCDK, 84 (85.7%) were identified antenatally, with Groote Schuur Hospital accounting for 60% of referrals. The cohort had a balanced sex distribution, 49 (50.0%) male, and left-sided involvement in 56 (57.1%). The median age at first renal clinic visit of 1.5 months (IQR 1–2) for kidney ultrasound and 2 months (IQR 1.5–3) for a [ 99m Tc]Tc-MAG3 scan. Median follow-up was 36 months (IQR 12–72). All patients exhibited a non-functioning kidney on [ 99m Tc]Tc-MAG3, with preserved function in the contralateral kidney. Table 1 Demographic characteristics of patients with multicystic dysplastic kidney (MCDK) Characteristic Frequency (n = 98) Percentage (%) Gender Male 49 50.0 Female 49 50.0 Distribution by age at first clinic visit 1 month ≤ 6 months 48 49.0 ≥ 6–12 months 6 6.1 > 12 months 1 1.0 Distribution by birthweight < 2.5Kg 5 5.1 ≥ 2.5kg 93 94.9 Diagnosis Prenatal 84 85.7 Postnatal 14 14.3 Presenting Complaints $ FMU scan – ‘suspected MCDK/cystic kidney’ 71 72.4 Abdominal mass 4 4.1 Suspected urinary tract infection 6 6.1 Incidental finding 4 4.1 Antenatal hydronephrosis 10 10.2 Acute kidney injury 2 2.0 Unreported 1 1.0 MCDK side Right 42 42.9 Left 56 57.1 Referral (n = 50) Groote Schuur Hospital 30 60.0 Mowbray Maternity Hospital 6 12.0 Private hospital 6 12.0 Vredenburg Hospital 3 6.0 George Hospital 1 2.0 Tygerberg Hospital 1 2.0 New Somerset Hospital 1 2.0 2 Military Hospital 1 2.0 Urology unit 1 2.0 $ Multiple options apply FMU: Fetomaternal (antenatal) ultrasound Patterns of associated genitourinary and extrarenal anomalies among children with MCDK (Table 2 ) Contralateral kidney abnormalities were observed in 17 children (17.3%), with duplex kidney being the most common anomaly (33.3%), frequently complicated by reflux and hydronephrosis or hydroureters. Other contralateral anomalies included ureteropelvic junction obstruction (27.8%), hydroureteronephrosis and hydronephrosis (each 11.1%), contralateral dysplasia (11.1%), and vesicoureteric reflux (22.2%). Ipsilateral hydroureters and ureterocoeles were identified in 4.1% of cases. Additionally, 8.2% of children had extra-renal anomalies, equally divided between syndromic and non-syndromic forms. Table 2 Distribution of abnormalities of the contralateral kidney on ultrasound and associated extrarenal anomalies Frequency (n = 17/98) Percent Associated anomalies 17 17.3 Duplex 6 33.3 • Uncomplicated 2 33.3% • Complicated 4 66.7% o With Reflux alone* 1 16.7 o With HU/HN and Reflux* 2 33.3 o With ureterocoele and HN 1 16.2 UPJO 5 27.8 Urinary tract dilatation Hydroureteronephrosis 2 11.1 Hydronephrosis 2 11.1 Dysplasia 2 11.1 VUR * 4 22.2 Associated abnormalities of the ipsilateral kidney on ultrasound (n = 4/98, 4.1%) Ureterocoele in bladder 2 2.0 Hydroureter 2 2.0 Extrarenal abnormalities (n = 8/98, 8.2%) Syndromic n = 4 Costello syndrome 1 1.0 4q deletion syndrome 1 1.0 Alagille’s syndrome 1 1.0 Trisomy 21 with ASD 1 1.0 Non-syndromic n = 4 Coarctation of Aorta + Cardiomyopathy 1 1.0 Hydrocolpos 1 1.0 Hemivertebrae (L4/L5) 1 1.0 Isolated oesophageal atresia 1 1.0 UPJO – ureteropelvic junction obstruction, VUR – vesicoureteric reflux** on [ 99m Tc]Tc-MAG3 only Estimated glomerular filtration rates, urine and radiology investigations of the study cohort Of the entire cohort, 81/98 were followed up beyond the first year. Of these, 63 (69.8%) had simple unilateral MCDK, while 18 (25.9%) had complex MCDK. As shown in Table 3 , 15 (18.5%) developed UTIs. One case of UTI was confirmed in the neonatal period. During later follow-up, 14 children (17.3%) experienced UTIs. The baseline median glomerular filtration rate (GFR) was 62 ml/min/1.73 m² (IQR 35–82), which increased to 121 ml/min/1.73 m² (IQR 90–147) at the last follow-up. Of the 14 children with a recorded eGFR at the final visit, five exhibited hyperfiltration, seven had normal GFRs, and two had persistently reduced GFR (< 90 ml/min/1.73 m²). MCUG were performed in four patients (22.2%) presenting with hydronephrosis, hydroureters, or suspected reflux based on contralateral kidney renogram findings. Of these, one had a dysplastic kidney and three had duplex kidneys; none demonstrated reflux on MCUG. Table 3 Serum creatinine, eGFR, urine and serial radiological investigation history of the study cohort Parameter Median (IQR) Median serum creatinine (µmol/L) at baseline 35.0 (24.5, 64.5) Median serum creatinine (µmol/L) at last visit 33.5 (27.2, 40.25) Median eGFR (ml/min/1.73m 2 ) at baseline (n = 21/81) 62 (35, 82) Median eGFR (ml/min/1.73m 2 ) at last visit (n = 14/81) 121 (90, 147) Frequency Percent Urinary Tract Infections (n = 81): 15 18.5 At presentation Organism isolated Escherichia Coli 1 1.2 At any time 14 17.3 Organism isolated Escherichia Coli 10 71.4 Klebsiella spp 2 14.3 Proteus spp 1 7.1 Citrobacter spp 1 7.1 Imaging MCUG done / vesicoureteric reflux absent 4 4.9% / (100%) Median (IQR) Changes in KUB characteristic findings Baseline N = 81 1 year N = 81 2 year N = 64 5 year N = 31 Size of affected kidney (cm) 4.9 (3.60–5.95) 4.1 (2.82–6.20) 4.3 (2.0–7.0) 2.0 (0.0–4.0) Size of contralateral kidney (cm) 5.5 (5.0–6.10) 6.8 (6.3–7.50) 7.6 (7.38–8.25) 9.0 (8.58–9.60) Compensatory hypertrophy of the contralateral kidney Compensatory hypertrophy of the contralateral kidney was observed in 80.2% of children, with prevalence rising from 7.4% at birth to 80.2% by five years, as shown in Fig. 2 . Complications of MCDK among the follow-up cohort of children : During follow-up, one child (1.2%) developed hypertension, and two children developed chronic kidney disease (eGFR < 90 ml/min/1.73 m²); all had contralateral kidney dysplasia. Additionally, two children exhibited persistent sub-nephrotic proteinuria: one with a duplex kidney and upper tract dilatation, and another with contralateral UPJO and 4q deletion syndrome. Involution of the MCDK Fifty-six children (69.1%) exhibited partial or complete regression of the affected kidney. Complete involution was observed at birth in five cases (6.1%), with cumulative rates of 25.9% at one year, 39.5% at two years, and 45.7% at five years, as illustrated in Fig. 3 . Among the 25 children (30.9%) whose kidneys did not involute, 44.0% showed an increase in size, and 56.0% remained stable. The mean age at involution for kidneys ≤ 5.0 cm at baseline was 1.5 ± 1.3 years, compared to 2.0 ± 1.4 years for those > 5.0 cm. The average initial size was 3.6 ± 1.4 cm in children who involuted, versus 6.0 ± 1.9 cm in those who did not. Predictors of MCDK involution: The Log-Rank (Mantel-Cox) test and Cox proportional hazards regression were employed to identify predictors of MCDK involution, as detailed in Table 4 . At the bivariate level, both initial MCDK size (p < 0.001) and compensatory hypertrophy of the contralateral kidney (p = 0.03) were significant predictors. The multivariate Cox regression model, which satisfied the proportional hazards assumption and demonstrated good fit (-2 Log Likelihood = 445.452; omnibus χ² (6) = 13.290, p = 0.039), revealed that only initial kidney size remained significant (p = 0.005; HR = 2.425, 95% CI: 1.311–4.485) for predicting involution. Specifically, children with an initial MCDK size of ≤ 5.0 cm were more than twice as likely to undergo involution over time compared to those with larger initial sizes. Covariate coding and hazard ratios are presented in Table 4 . Table 4 Predictors of involution of MCDK Involution present Involution absent Bivariate analysis Multivariate Analysis Log-rank (Mantel-Cox) p-value Cox Proportional Regression p-value HR (95% CI) Type of MCDK 0.626 0.831 0.930 (0.478–1.809) Simple 44 (69.8%) 19 (30.2%) Complex 12 (66.7%) 6 (33.3%) Gender 0.330 0.539 0.840 (0.481–1.466) Male 30 (75.0%) 10 (25.0%) Female 26 (63.4%) 15 (36.6%) Compensatory hypertrophy 0.030* 0.057 2.181 (0.977–4.867) Yes 49 (75.4%) 16 (24.6%) No 7 (43.8%) 9 (56.3%) Mean Kidney size (initial) 3.6 ± 1.4 6.0 ± 1.9 < 0.001* < 0.001 0.970 (0.954–0.986) ** Kidney Size (≤ 5.0cm) 0.002* 0.005 2.425 (1.311–4.485) ** Yes 39 (81.3%) 9 (18.8%) No 17 (51.5%) 16 (48.5%) Time at diagnosis 0.422 0.222 1.474 (0.791–2.746) Antenatal 41 (71.9%) 16 (28.1%) Postnatal 15 (62.5%) 9 (37.5%) Contralateral abnormality 0.626 0.831 0.930 (0.478–1.809) Yes 12 (66.7%) 6 (33.3%) No 44 (68.9%) 19 (30.2%) Laterality of MCDK 0.346 0.899 1.037 (0.589–1.825) Right 23 (63.9%) 13 (36.1%) Left 33 (73.3%) 12 (26.7%) * / ** statistically significant in bivariate and multivariate analysis t-test statistic 7.1652 mean difference: -2.40; (95% CI; − 3.067 to – 1.733) Surgical and follow-up outcomes During follow-up, three children (3.7%) required surgery; one nephrectomy for persistently increasing MCDK > 10 cm with intra-abdominal compromise and two had pyeloplasty for contralateral obstruction. At the last clinic visit, 56.8% remained under follow-up, 12.3% had transitioned to adolescent care, 2.5% were transferred out, and 28.4% were lost to follow-up. No malignancies or MCDK-related deaths were observed. Discussion This study described the epidemiology of paediatric MCDK as seen in a tertiary specialist renal outpatient clinic in sub-Saharan Africa. MCDK, typically identified in either the perinatal or postnatal period, has a reported incidence of 1 in 2,200 to 4,300 live births [2,3]. However, these estimates were derived exclusively from data outside sub-Saharan Africa. The apparent underdiagnosis of MCDK in this region may plausibly reflect both limited detection and genetic variability. In our cohort, MCDK accounted for approximately 1 in 16 new renal cases seen at the outpatient clinic during the study period, making it the most common cystic dysplastic kidney disease observed. By comparison, an earlier study by Lala[19] identified 59 cases among 10,445 admissions over 30 years in Johannesburg, corresponding to a prevalence of 5.7 per 1,000 admissions, although differences in denominators limit direct comparison. Notably, our findings demonstrate an increasing incidence of MCDK over the past decade, which may be attributable to enhanced expertise in feto-maternal ultrasonography, improvements in ultrasound technology, and our role as a regional referral centre. Accurately assessing the incidence of MCDK is challenging due to its often-asymptomatic presentation until later life [33]. In South Africa, the lack of multicentre or nationwide registries for CAKUT surveillance precludes reliable regional estimates. Furthermore, the observed reduction in incidence in 2020 is most likely a consequence of reduced healthcare access during the COVID-19 pandemic. The predominance of prenatal ultrasound diagnoses in this cohort signifies progress in early MCDK detection relative to an earlier South African finding [19]. Referrals primarily originated from tertiary centres, indicating improved diagnostic precision attributable to technological advancements and consensus guidelines. Most cases were identified during third-trimester scans, consistent with reports from Spain [34] and a recent meta-analysis by Erlich and colleagues [35]. Furthermore, contemporary studies demonstrate that prenatal diagnostic accuracy for MCDK has reached rates as high as 91.3 − 98.0% [14,33,36,37], underscoring the increasing effectiveness of prenatal ultrasound in this context. Approximately one-fifth of children in this cohort exhibited contralateral kidney abnormalities, consistent with the reported range of 5–43% in other studies [21], though lower than the 33% pooled estimate from the meta-analysis by Schreuder and colleagues. 3 Vesicoureteric reflux (VUR) is frequently cited as the most common abnormality, with pooled rates of 17–20% [3,35]. However, it was not reflected in our cohort. Notably, reflux was detected by [ 99m Tc]Tc-MAG3 renogram in a small number of cases, but not confirmed by MCUG, as previously observed in South African studies [19,38]. This finding underpins the selective use of MCUG, reserving it for cases with contralateral or bladder abnormalities on kidney ultrasound scan, rather than routine application in all children with MCDK. Our study found duplex kidney to be the most common contralateral abnormality, observed in one-third of affected cases, a finding scarcely reported in other studies. Particularly, kidney duplication was not identified as an abnormality in earlier systematic reviews [3,35], with only sporadic reports documenting such findings [39,40]. Ureteropelvic junction obstruction was the second most frequent contralateral anomaly, with a subset of patients requiring surgical intervention to preserve kidney function. Ipsilateral abnormalities were rare, affecting less than a tenth of the cohort, markedly lower than the prevalence reported in other studies [33,41,42]. The primary ipsilateral findings were ureterocoeles and hydroureters, whereas previous studies have also described vesicoureteral reflux and internal genital tract anomalies [41,42]. Consistent with the literature, this study found that approximately 1 in 10 children with MCDK had extra-renal anomalies, including rare syndromic associations suggestive of a possible genetic component in some cases [43–46]. Although the prevalence of extrarenal associations in our cohort was lower than previously reported rates of 25–48% [37,47] these findings emphasise the importance of thorough physical examination in children with MCDK. Compensatory hypertrophy of the contralateral kidney is well-documented in MCDK and is associated with involution of the affected kidney after two years of age [48]. In this study, compensatory hypertrophy was observed in less than one-tenth of children at birth, increasing to four-fifths by five years, consistent with previous reports of rapid early growth in the functional kidney[5,9,14,15,49–51]. However, about one-fifth of our cohort did not develop compensatory hypertrophy, highlighting the need for ongoing surveillance, as the absence of hypertrophy may indicate underlying kidney dysfunction [27]. Studies have reported on the involution rates of MCDK over time, with approximately 5–6% showing complete involution at birth [3], a finding mirrored in this study. Our cohort demonstrated cumulative involution probabilities, aligning with international data [4,22,34,52,53]. Variations in involution rates across studies may reflect differences in follow-up duration, sample size, and scan quality. Consistent with earlier studies, an initial MCDK size of ≤ 5 cm was found to be a positive predictor of complete involution [4,8,53] At presentation, most children had low eGFRs, reflecting immature kidney function due to young age. Only a subset of patients had follow-up eGFR measured, with median values increasing to normal levels and some demonstrating hyperfiltration without proteinuria. Two children developed CKD, both with complex contralateral abnormalities and no involution of the affected kidney. These findings align with previous studies highlighting variability in kidney function and proteinuria among children with MCDK. [22,53,54]. Furthermore, our findings buttress the necessity for baseline and annual monitoring of kidney function and proteinuria to detect early signs of kidney injury, regardless of perceived risk. Given the potential for hyperfiltration and the implications of Brenner’s and Barker’s hypotheses, children with MCDK, particularly those with low birth weight or complex type disease, may require long-term surveillance and lifestyle counselling to mitigate future cardiometabolic and chronic kidney risks [9,55]. At the last follow-up clinic visit, most children with MCDK remained under surveillance, while a proportion had been transferred to adolescent care or to facilities outside Cape Town. Notably, nearly one-quarter of the cohort were lost to follow-up, a trend potentially attributed to caregiver reassurance following favourable prognoses, a phenomenon previously observed in another study [56]. This is concerning, given the enduring risk of chronic kidney disease, as evidenced by the Solitary Functioning Kidney: Aetiology and Prognosis (SOFIA) study, which reported that a substantial proportion of patients with a solitary functioning kidney exhibited markers of kidney injury by late adolescence [11]. Even in children with unilateral MCDK and a normal contralateral kidney, the risk of developing stage II CKD remains appreciable by age ten [50,55,57]. These findings highlight the necessity of thorough education for caregivers regarding long-term renal risks and highlight the importance of implementing strategies to improve follow-up adherence. No cases of malignancy, mortality, or need for kidney replacement therapy were reported over the study period. Conservative management, involving serial ultrasonography until spontaneous involution, proved effective, offering reduced procedural risks and financial savings, as similarly noted in earlier studies. 12,21 The optimal frequency of kidney ultrasound scan monitoring remains contentious, with protocols ranging from intensive early follow-up to interval-based surveillance at key developmental milestones [16,22,54,55,58]. In light of this cohort’s largely benign short-term outcomes, adopting a less intensive follow-up regimen, including kidney ultrasound scans at birth, one month, two years, five years, and ten years, respectively, as suggested by Hains et al.[21] and Aslam et al.[22], appears appropriate for the present study’s setting. We suggest this approach because our protocol of a more frequent follow-up regimen did not necessarily improve clinical follow-up compliance. Therefore, this study demonstrates that paediatric MCDK can be accurately diagnosed, monitored, and managed conservatively in resource-constrained settings. Moreover, reducing the number of clinic appointments could enhance patient compliance with follow-up visits and alleviate pressure on the already overburdened healthcare system. This single-centre study was constrained by its retrospective design, with some incomplete or missing data, variability in the documentation of clinical notes and laboratory test requests, which could potentially impact the reliability and generalisability of the findings and introduce possible bias. Conclusion This study found that most children with MCDK experience favourable short-term outcomes, particularly in the absence of contralateral abnormalities. However, a considerable subset presented with duplex kidneys, lacked compensatory hypertrophy, or showed no involution, underscoring the need for continued surveillance. Closer monitoring may be warranted for certain groups, including preterm neonates, those with initial kidney sizes exceeding 5 cm, complex contralateral abnormalities, and those children with either increasing or non-regressing MCDK sizes suggesting maladaptive compensation. Declarations Ethical approval for this study was granted by the Human Research Ethics Committee of the University of Cape Town (HREC:805/2024) and the ethics committee of the Red Cross War Memorial Hospital (RXH: RCC 451/WC_220410_034). Due to the retrospective nature of the study, a waiver of parental consent was also approved by the Institutional Ethics Committees (HREC:805/2024). The study was conducted in accordance with the Declaration of Helsinki. Availability of data and materials: data will be made available on reasonable request and ethical approval of the institution. Competing interests: The authors declare that they have no competing interests Funding: none Authors' contributions: Conceptualisation: [Asthon Coetzee, Mignon McCulloch, Anita Brink, Peter Nourse, Datonye Briggs]; Methodology: [Datonye Briggs, Ashton Coetzee, Khanyisile Hlongwa]; Formal analysis and investigation: [Datonye Briggs], Writing - original draft preparation: [Datonye Briggs]; Writing - review and editing: [Datonye Briggs, Ashton Coetzee, Khanyisile Hlongwa, Anita Brink, Peter Nourse, Mignon McCulloch], Supervision: [Ashton Coetzee (lead), Khanyisile Hlongwa]. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Acknowledgements: The authors acknowledge the International Society of Nigeria (ISN) and the International PNA for making the training of the first / corresponding Author possible. References Emma F, Goldstein SL, Bagga A, Bates CM, Shroff R, eds. Pediatric Nephrology . Springer International Publishing; 2022. doi:10.1007/978-3-030-52719-8 Dillon E, Ryall A. A 10 year audit of antenatal ultrasound detection of renal disease. The British Journal of Radiology . 1998;71(845):497-500. doi:10.1259/bjr.71.845.9691894 Schreuder MF, Westland R, Van Wijk JAE. Unilateral multicystic dysplastic kidney: a meta-analysis of observational studies on the incidence, associated urinary tract malformations and the contralateral kidney. Nephrology Dialysis Transplantation . 2009;24(6):1810-1818. doi:10.1093/ndt/gfn777 Eickmeyer AB, Casanova NF, He C, et al. The natural history of the multicystic dysplastic kidney – Is limited follow-up warranted? Journal of Pediatric Urology . 2014;10(4):655-661. doi:10.1016/j.jpurol.2014.06.001 Gaither TW, Patel A, Patel C, Chuang K wen, Cohen RA, Baskin LS. Natural History of Contralateral Hypertrophy in Patients with Multicystic Dysplastic Kidneys. Journal of Urology . 2018;199(1):280-286. doi:10.1016/j.juro.2017.06.075. Cambio AJ, Evans CP, Kurzrock EA. Non-surgical management of multicystic dysplastic kidney. BJU Int . 2008;101(7):804-808. doi:10.1111/j.1464-410X.2007.07328.x Unilateral multicystic dysplastic kidney: does initial size matter? Pediatr Nephrol . 2012;27(8):1335-1340. doi:10.1007/s00467-012-2141-9 Sarhan OM, Alghanbar M, Alsulaihim A, Alharbi B, Alotay A, Nakshabandi Z. Multicystic dysplastic kidney: Impact of imaging modality selection on the initial management and prognosis. Journal of Pediatric Urology . 2014;10(4):645-649. doi:10.1016/j.jpurol.2014.03.004 Mansoor O, Chandar J, Rodriguez MM, et al. Long-term risk of chronic kidney disease in unilateral multicystic dysplastic kidney. Pediatr Nephrol . 2011;26(4):597-603. doi:10.1007/s00467-010-1746-0 Dogan SC, Bayram TM, Aybar MS. Unilateral multicystic dysplastic kidney in children. The Turkish Journal of Pediatrics . 2014;56:75-79. PMID: 24827951. Groen In ’T Woud S, Westland R, Feitz WFJ, et al. Clinical Management of Children with a Congenital Solitary Functioning Kidney: Overview and Recommendations. European Urology Open Science . 2021;25:11-20. doi:10.1016/j.euros.2021.01.003 Chang A, Sivananthan D, Nataraja RM, Johnstone L, Webb N, Lopez PJ. Evidence-based treatment of multicystic dysplastic kidney: a systematic review. Journal of Pediatric Urology . 2018;14(6):510-519. doi:10.1016/j.jpurol.2018.09.018 Feldenberg LR, Siegel NJ. Clinical course and outcome for children with multicystic dysplastic kidneys. Pediatric Nephrology . 2000;14(12):1098-1101. doi:10.1007/s004670000391 Moralioglu S, Celayir AC, Bosnali O, Pektas OZ, Bulut IK. Single center experience in patients with unilateral multicystic dysplastic kidney. J Pediatr Urol . 2014;10(4):763-768. doi:10.1016/j.jpurol.2014.03.008 Akbalik Kara M, Taktak A, Alparslan C. Retrospective evaluation of the pediatric multicystic dysplastic kidney patients: experience of two centers from southeastern Turkey. Turk J Med Sci . 2021;51(3):1331-1337. doi:10.3906/sag-2011-175 Grabnar J, Rus RR. Is renal scintigraphy really a necessity in the routine diagnosis of congenital solitary kidney? Pediatr Surg Int . 2019;35(6):729-735. doi:10.1007/s00383-019-04478-1 Chaki S, Mclarty R, Mzolo I, Rajan S, Chipongo H. A Rare Case of Antenatal Bilateral Multicystic Dysplastic Kidney Disease: An Unusual Presentation in a Neonate. Clinical Case Reports . 2025;13(4):e70407. doi:10.1002/ccr3.70407 Musa A, Umar L, Bugaje M, Rosamund A. Multicystic dysplastic kidney with associated contralateral renal ectopia in an infant: A rare association. Sub-Saharan Afr J Med . 2016;3(2):122. doi:10.4103/2384-5147.184381 Nilesh L. Multicystic Dysplastic Kidney Disease at Chris Hani Baragwanath Academic Hospital over a Thirty Year Period . University of Witwatersrand; 2017. Okoronkwo NC, Levy C, Khumalo T, Moonsamy G. Congenital anomalies of the kidney and the urinary tract in a South African paediatric nephrology setting. South African Journal of Child Health . 2020;14(1):40-44. doi:10.7196/SAJCH.2020.v14.i1.01666 Hains DS, Bates CM, Ingraham S, Schwaderer AL. Management and etiology of the unilateral multicystic dysplastic kidney: a review. Pediatr Nephrol . 2009;24(2):233-241. doi:10.1007/s00467-008-0828-8 Aslam M. Unilateral multicystic dysplastic kidney: long term outcomes. Archives of Disease in Childhood . 2006;91(10):820-823. doi:10.1136/adc.2006.095786 Jawa NA, Rosenblum ND, Radhakrishnan S, Pearl RJ, Levin L, Matsuda-Abedini M. Reducing Unnecessary Imaging in Children With Multicystic Dysplastic Kidney or Solitary Kidney. Pediatrics . 2021;148(2):e2020035550. doi:10.1542/peds.2020-035550 Stuck KJ, Koff SA, Silver TM. Ultrasonic features of multicystic dysplastic kidney: expanded diagnostic criteria. Radiology . 1982;143(1):217-221. doi:10.1148/radiology.143.1.7063729 Lebowitz RL, Olbing H, Parkkulainen KV, Smellie JM, Tamminen-Möbius TE. International system of radiographic grading of vesicoureteric reflux. Pediatr Radiol . 1985;15(2):105-109. doi:10.1007/BF02388714 Choi YH, Cheon JE, Kim WS, Kim IO. Ultrasonography of hydronephrosis in the newborn: a practical review. Ultrasonography . 2016;35(3):198-211. doi:10.14366/usg.15073 Wang MK, Gaither T, Phelps A, Cohen R, Baskin L. The Incidence and Durability of Compensatory Hypertrophy in Pediatric Patients with Solitary Kidneys. Urology . 2019;129:188-193. doi:10.1016/j.urology.2019.04.003 Biassoni L, Gordon I. Radioisotope imaging of the kidney and urinary tract. In: Pediatric Urology . Elsevier; 2010:108-126. doi:10.1016/B978-1-4160-3204-5.00008-6 Flynn JT, Kaelber DC, Baker-Smith CM, et al. Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. Pediatrics . 2017;140(3):e20171904. doi:10.1542/peds.2017-1904 Schwartz GJ, Muñoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol . 2009;20(3):629-637. doi:10.1681/ASN.2008030287 Huang Y, Yang X, Zhang Y, et al. Correlation of urine protein/creatinine ratios to 24-h urinary protein for quantitating proteinuria in children. Pediatr Nephrol . 2020;35(3):463-468. doi:10.1007/s00467-019-04405-5 Stevens PE, Ahmed SB, Carrero JJ, et al. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International . 2024;105(4):S117-S314. doi:10.1016/j.kint.2023.10.018 Urisarri A, Gil M, Mandiá N, et al. Retrospective study to identify risk factors for chronic kidney disease in children with congenital solitary functioning kidney detected by neonatal renal ultrasound screening. Medicine . 2018;97(32):e11819. doi:10.1097/MD.0000000000011819 Carazo-Palacios ME, Couselo-Jerez M, Serrano-Durbá A, et al. Multicystic dysplastic kidney: Assessment of the need for renal scintigraphy and the safety of conservative treatment. Actas Urológicas Españolas (English Edition) . 2017;41(1):62-67. doi:10.1016/j.acuroe.2016.11.004 Erlich T, Lipsky AM, Braga LH. A meta-analysis of the incidence and fate of contralateral vesicoureteral reflux in unilateral multicystic dysplastic kidney. Journal of Pediatric Urology . 2019;15(1):77.e1-77.e7. doi:10.1016/j.jpurol.2018.10.023 Scala C, McDonnell S, Murphy F, et al. Diagnostic accuracy of midtrimester antenatal ultrasound for multicystic dysplastic kidneys. Ultrasound in Obstet & Gyne . 2017;50(4):464-469. doi:10.1002/uog.17305 Alamir A, Al Rasheed SA, Al Qahtani AT, et al. The Outcome of Multicystic Dysplastic Kidney Disease Patients at King Abdulaziz Medical City in Riyadh. Cureus . Published online April 22, 2023. doi:10.7759/cureus.37994 Kala UK, Jacobs DWC. Evaluation of urinary tract infection in malnourished black children. Annals of Tropical Paediatrics . 1992;12(1):75-81. doi:10.1080/02724936.1992.11747549 Nugraha HG, Adibrata ASP. Unilateral multicystic dysplastic kidney disease associated with ipsilateral ureteric bud remnant and contralateral duplex collecting system. Radiology Case Reports . 2023;18(6):2289-2292. doi:10.1016/j.radcr.2023.03.048 Chun-Chen L, Jeng-Daw T, Jin-Cherng S, Hsiang-Ju L, Brian Pin-Hsuan C. Segmental multicystic dysplastic kidney in children: clinical presentation, imaging finding, management, and outcome. Journal of Pediatric Surgery . 2010;45(9):1856-1862. doi:10.1016/j.jpedsurg.2010.03.028 Merrot T, Lumenta DB, Tercier S, Morisson-Lacombes G, Guys JM, Alessandrini P. Multicystic dysplastic kidney with ipsilateral abnormalities of genitourinary tract: experience in children. Urology . 2006;67(3):603-607. doi:10.1016/j.urology.2005.09.062 Mathiot A, Liard A, Eurin D, Dacher JN. Prenatally detected multicystic renal dysplasia and associated anomalies of the genito-urinary tract. J Radiol . 2002;83(6 Pt 1):731-735. Teles-Silva C, Martins F, Costa S, et al. Renal Dysplasia and Progressive Renal Failure in a Newborn with Interstitial Chromosome 4 Deletion 4q25-28.3: A New Phenotype? J Pediatr Genet . 2021;10(01):039-044. doi:10.1055/s-0039-1701043 Martin SR, Garel L, Alvarez F. Alagille’s syndrome associated with cystic renal disease. Arch Dis Child . 1996;74(3):232-235. doi:10.1136/adc.74.3.232 Ozunan Akil I, Evrengul H, Cetin M, Taneli C. Renal ve Ürolojik Bulgular Costello Sendromu ile Iliskili midir? Is Renal and Urologic Findings Associated with Costello Syndrome?: Case Repor. Turkiye Klinikleri J Pediatr . 2013;22(2):78-82. Hoffman JD, Bianchi DW, Sullivan LM, et al. Down syndrome serum screening also identifies an increased risk for multicystic dysplastic kidney, two-vessel cord, and hydrocele. Prenatal Diagnosis . 2008;28(13):1204-1208. doi:10.1002/pd.2082 Chetty S. Multicystic dysplastic kidney. American Journal of Obstetrics and Gynecology . 2021;225(5):B21-B22. doi:10.1016/j.ajog.2021.06.046 McArdle Z, Schreuder MF, Moritz KM, Denton KM, Singh RR. Physiology and Pathophysiology of Compensatory Adaptations of a Solitary Functioning Kidney. Front Physiol . 2020;11:725. doi:10.3389/fphys.2020.00725 Singh JK, Kanojia RP, Narasimhan KL. Multicystic dysplastic kidney in children — A need for conservative and long term approach. Indian J Pediatr . 2009;76(8):809-812. doi:10.1007/s12098-009-0117-y John U, Rudnik-Schöneborn S, Zerres K, Misselwitz J. Kidney growth and renal function in unilateral multicystic dysplastic kidney disease. Pediatric Nephrology . 1998;12(7):567-571. doi:10.1007/s004670050506 Alaygut D, Soylu A, Kasap B, Türkmen M, Çakmakci H, Kavukcu S. The Relationships Between Renal Compensatory Hypertrophy Etiologic Factors and Anthropometric Development in the Pediatric Age Group. Urology . 2013;82(2):442-447. doi:10.1016/j.urology.2013.03.024 Kopac M, Kordic R. Associated Anomalies and Complications of Multicystic Dysplastic Kidney. Pediatric Reports . 2022;14(3):375-379. doi:10.3390/pediatric14030044 Hayes WN, Watson AR, Trent & Anglia MCDK Study Group. Unilateral multicystic dysplastic kidney: does initial size matter? Pediatr Nephrol . 2012;27(8):1335-1340. doi:10.1007/s00467-012-2141-9 Sharada S, Vijayakumar M, Nageswaran P, Ekambaram S, Udani A. Multicystic dysplastic kidney: A retrospective study. Indian Pediatr . 2014;51(8):641-643. doi:10.1007/s13312-014-0467-z Schreuder MF. Life with one kidney. Pediatr Nephrol . 2018;33(4):595-604. doi:10.1007/s00467-017-3686-4 Damen-Elias HAM, Stoutenbeek PH, Visser GHA, Nikkels PGJ, De Jong TPVM. Concomitant anomalies in 100 children with unilateral multicystic kidney. Ultrasound in Obstet & Gyne . 2005;25(4):384-388. doi:10.1002/uog.1851 Mashat SD, El-Desoky SM, Abdulaziz Kari J. Outcome of Multi-Cystic Dysplastic Kidneys in Children. Iran J Pediatr . 2015;25(5):e2991. doi:10.5812/ijp.2991 Hsu PY, Yu CH, Lin K, Cheng YC, Chang CH, Chang FM. Prenatal diagnosis of fetal multicystic dysplastic kidney in the era of three-dimensional ultrasound: 10-year experience. Taiwanese Journal of Obstetrics and Gynecology . 2012;51(4):596-602. doi:10.1016/j.tjog.2012.09.015 Additional Declarations No competing interests reported. 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2","display":"","copyAsset":false,"role":"figure","size":60245,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eCumulative frequency of compensatory hypertrophy per year during follow-up\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7706913/v1/d1afd98113ca937e4a6b07c3.png"},{"id":94758929,"identity":"741a7ba8-1649-4e11-804a-3eade1ebf192","added_by":"auto","created_at":"2025-10-30 11:52:34","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":87712,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eCumulative involution rates of the affected kidney\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7706913/v1/12c7e62f8b2a614a0164fb33.png"},{"id":97178930,"identity":"1b3f1ca5-8808-4f8e-b63d-8fd40ed144ea","added_by":"auto","created_at":"2025-12-01 16:14:03","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1811098,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7706913/v1/7f98d1f8-636d-4a6e-a5ba-a8fbd411d4d7.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Paediatric Multicystic Dysplastic Kidney Disease in Cape Town, South Africa","fulltext":[{"header":"Take-home messages","content":"\u003cul\u003e\u003cli\u003e\u003cp\u003eIn children with MCDK, conservative management is sufficient, and there is no need for nephrectomy.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eFrequency of kidney ultrasound scan monitoring at birth, 1 month, 2 years, 5 years, and 10 years (depending on resource availability) is a suggested approach.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eA yearly follow-up kidney health assessment – including blood pressure and urine dipstick checks, with reassessments every one or two years, is a reasonable approach.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e"},{"header":"Introduction","content":"\u003cp\u003eMulticystic dysplastic kidney disease (MCDK) is a significant congenital anomaly of kidney development, characterised by multiple non-communicating cysts of varying sizes within a non-functioning parenchyma [1]. This genitourinary malformation is frequently identified in utero or during the early neonatal period, with an incidence of approximately 1 in 2,200 to 4,300 live births [2,3]. MCDK arises from defective and incomplete nephron formation resulting from maldevelopment of the ureteric bud during early kidney morphogenesis [4]. It is one of the leading causes of a palpable abdominal mass in infants, second only to hydronephrosis due to ureteropelvic junction obstruction (UPJO).\u003csup\u003e4\u003c/sup\u003e While MCDK typically affects a single kidney, bilateral involvement is rare but invariably fatal, as it is associated with kidney failure and pulmonary hypoplasia [4].\u003c/p\u003e\u003cp\u003eStudies suggest that involution of the multicystic dysplastic kidney is most pronounced within the first two to three years of life [5,6], with approximately 10% occurring by the first year, 35.0% by the second year, and between 38.5% and 47% by the fifth year [4,7]. Nonetheless, concerns persist regarding an elevated risk of kidney failure in children with MCDK, particularly among those lacking compensatory hypertrophy of the contralateral kidney[5] Furthermore, up to one-third of affected children may exhibit abnormalities in the solitary functioning contralateral kidney [3], such as vesicoureteral reflux (VUR)[8], ureteropelvic junction obstruction, dysplasia, or positional anomalies, all of which increase the risk of chronic kidney disease [9\u0026ndash;11]. Although less frequently reported, hypertension develops in 3.2% of cases [12], urinary tract infections in 5.0%\u0026ndash;34.7% [13\u0026ndash;16], and malignant transformation in 0.07% [12].\u003c/p\u003e\u003cp\u003eThe epidemiology and outcomes of paediatric MCDK in sub-Saharan Africa remain largely underreported. The existing literature is predominantly limited to case reports or small-scale studies [17\u0026ndash;20], which hinders a comprehensive understanding of MCDK in this setting. Furthermore, an important aspect of MCDK management is determining the appropriate frequency of ultrasonographic surveillance, which currently lacks standardisation [21,22]. A recent Canadian study recommended scheduled ultrasounds for children with congenital solitary kidney, including MCDK, at specific intervals (birth, 6 months, 2, 5, 10, and 15 years) to minimise unnecessary imaging and optimise resource utilisation [23]; however, it remains unclear what occurs in Africa. Therefore, this study sought to address these gaps by sharing our experience among children with MCDK seen at a tertiary paediatric specialist hospital in sub-Saharan Africa.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eThis retrospective study evaluated all children (\u0026lt;\u0026thinsp;13 years) diagnosed with MCDK by either antenatal or postnatal abdominopelvic ultrasound, for whom a corresponding confirmatory Mercaptotriglycine ([\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3) scan was performed at the Red Cross War Memorial Children\u0026rsquo;s Hospital (RCWMCH) in Cape Town, South Africa, over ten years from 1st January 2014 to 31st December 2023.\u003c/p\u003e\u003cp\u003eAt the RCWMCH, children presenting with suspected MCDK, dysplastic cystic kidneys, unilateral renal agenesis, abdominal masses, hydronephrosis, suspected or confirmed urinary tract infection are typically referred for specialist follow-up in the paediatric nephrology clinic. Following an initial or repeat kidney ultrasound, conducted shortly after birth or within the first month of life, a confirmatory [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 scan is routinely performed within six to eight weeks, in accordance with current standards of care, to differentiate dysplastic kidneys with preserved function from solitary functioning kidneys.\u003c/p\u003e\u003cp\u003eDiagnosis of MCDK was based on expanded kidney ultrasound radiological criteria [24], with confirmation of non-functionality established by a [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 scan demonstrating a differential kidney function of zero percent. In confirmed cases, serial ultrasound examinations are scheduled at birth, and then at 3, 6, 12, 24, 60, and 120 months. This is done to monitor involution of the MCDK and to assess growth or anomalies of the contralateral kidney. Repeat [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 diuretic scans are reserved for patients exhibiting worsening contralateral hydronephrosis or recurrent urinary tract infections. Surgical intervention is rarely indicated and typically considered only if the dysplastic kidney exceeds 5 cm and increases in size to cause abdominal symptoms, or in cases of recurrent urinary tract infections, unexplained hypertension, or suspected malignancy.\u003c/p\u003e\u003cp\u003eAll kidney ultrasound and nuclear medicine scan records are systematically archived in the Picture Archiving and Communication Systems (PACS) and Venus Share Archiving communications system, facilitating digital storage, straightforward retrieval, and comparative referencing with earlier imaging studies.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eDefinition of terms:\u003c/h2\u003e\u003cp\u003e\u003cb\u003eVesicoureteral reflux (VUR\u003c/b\u003e) staging on MCUG was classified according to the International Reflux Study Committee Classification [25]. \u003cb\u003eUreteropelvic junction obstruction (UPJO)\u003c/b\u003e was defined as the absence of ureter dilatation despite the kidney pelvis exceeding 10\u0026ndash;15 mm, calyceal dilatation and an abnormal diuretic renogram pattern. \u003cb\u003eA duplex system\u003c/b\u003e was defined as a single kidney unit drained by two collecting systems [26]. A unilateral MCDK without genitourinary abnormalities in the bladder or contralateral kidney is a \u003cb\u003esimple MCDK\u003c/b\u003e, and a unilateral MCDK with genitourinary abnormalities is a \u003cb\u003ecomplex MCDK\u003c/b\u003e [19]. \u003cb\u003eComplete involution\u003c/b\u003e refers to the absence of MCDK evident on the kidney ultrasound. The age at which MCDK becomes undetectable is recognised as the time of complete involution [4]. \u003cb\u003ePartial involution\u003c/b\u003e indicates a decrease in the size of MCDK, as demonstrated by previous serial kidney ultrasound assessments [4]. \u003cb\u003eCompensatory hypertrophy of the contralateral kidney\u003c/b\u003e was defined as having a bipolar diameter exceeding two standard deviations above the age-appropriate mean of a normal kidney. In contrast, \u003cb\u003ethe absence of hypertrophy in the contralateral kidney\u003c/b\u003e was indicated by measurements that fall one standard deviation below the mean value of a normal kidney for the corresponding age [27]. \u003cb\u003eUrinary Tract Infection (UTI)\u003c/b\u003e was characterised by the presence of pyuria (\u0026ge;\u0026thinsp;5 white blood cells per high-power field) and/or a positive leukocyte esterase test or nitrite, along with a positive urine culture. A UTI was diagnosed if a suprapubic bladder aspiration reveals growth of a single bacterium\u0026thinsp;\u0026gt;\u0026thinsp;10\u003csup\u003e3\u003c/sup\u003e or if a midstream clean-void urine sample shows\u0026thinsp;\u0026ge;\u0026thinsp;10\u003csup\u003e5\u003c/sup\u003e colony-forming units/ml in toilet-trained children. Additionally, growth of \u0026ge;\u0026thinsp;5 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e colony-forming units/mL from a transurethral catheterised specimen was also considered a UTI [15]. An \u003cb\u003euncomplicated duplex kidney\u003c/b\u003e has two renal moieties with a different pelvicalyceal system, and a \u003cb\u003ecomplicated duplex kidney\u003c/b\u003e is one with incomplete duplication, obstructed drainage from a ureterocoele, hydronephrosis, reflux, dysplasia or reduced function [28].\u003c/p\u003e\u003cp\u003e\u003cb\u003eHypertension\u003c/b\u003e: systolic and/or diastolic blood pressure greater than or equal to the 95th percentile (adjusted for age, gender and height) on at least three different occasions [29]. \u003cb\u003eEstimated glomerular filtration rate (eGFR)\u003c/b\u003e: The modified bedside Schwartz method was used with the measured height(cm) and serum creatinine [30]. \u003cb\u003eProteinuria\u003c/b\u003e: protein creatinine ratio (g/g) on a spot urine sample\u0026thinsp;\u0026gt;\u0026thinsp;0.20 in children over two years of age and \u0026gt;\u0026thinsp;0.50 in infants and toddlers aged 6 to 24 months [31]. \u003cb\u003eChronic kidney disease (CKD)\u003c/b\u003e was staged according to KDIGO classification using the eGFR: stage 1 (\u0026gt;\u0026thinsp;90 ml/min/1.73 m\u003csup\u003e2\u003c/sup\u003e with renal parenchymal damage), stage 2 (90\u0026ndash;60 ml/min/1.73 m\u003csup\u003e2\u003c/sup\u003e), stage 3 (60\u0026ndash;30 ml/min/1.73 m\u003csup\u003e2\u003c/sup\u003e), stage 4 (30\u0026ndash;15 ml/min/1.73 m\u003csup\u003e2\u003c/sup\u003e), or stage 5 (\u0026lt;\u0026thinsp;15 ml/min/1.73 m\u003csup\u003e2\u003c/sup\u003e) [32]. A child was considered \u003cb\u003elost to follow-up (LTFU)\u003c/b\u003e after having consecutively missed at least two years of scheduled follow-up appointments.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eundefined\u003c/h3\u003e\n\u003cdiv class=\"Heading\"\u003e\u003cb\u003eData Collection and flow of eligible children through the study\u003c/b\u003e:\u003c/div\u003e\u003cp\u003eA comprehensive sampling frame included all eligible children who underwent both [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 and kidney ultrasound scans during the study period, identified from institutional databases. Data were systematically extracted using a standardised proforma from case notes, clinician request forms, and scan reports.\u003c/p\u003e\u003cp\u003eThe following variables were collected: patient demographic and anthropometric details at the time of MCDK diagnosis; indication and timing of both KUB and [99mTc]Tc-MAG3 scans; physical examination findings; and serum creatinine levels, where available. Each KUB scan report was reviewed to document the type of MCDK, affected kidney size (mm), number of cysts, anteroposterior diameter (APD), as well as the size (mm), corticomedullary differentiation (CMD), and the presence of a visible ureter in the unaffected kidney. Correspondingly, [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 reports were scrutinised for differential function in each kidney, evidence of obstruction, and confirmation or exclusion of MCDK non-functionality.\u003c/p\u003e\u003cp\u003eAdditional data were extracted regarding findings from micturating cystourethrograms (MCUG), which were performed typically following the presence of upper tract dilatation on ultrasound scan or reflux suggested on [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3. The presence of concomitant renal or extra-renal anomalies, as well as complications such as hypertension, recurrent urinary tract infections, or malignant transformation, was also recorded. Clinical outcomes were documented, including involution status (complete or partial), kidney function (if recorded during or at the last follow-up visit), management approach (conservative or surgical), requirement for kidney supportive therapy, and final status (ongoing follow-up, transition to adolescent/adult care, loss to follow-up, or death).\u003c/p\u003e\u003cp\u003eData were analysed using IBM SPSS version 30.0.0. Normality of the collated data was assessed, with continuous variables summarised as means and standard deviations for normally distributed data, or as medians and interquartile ranges (IQR) otherwise; trends were illustrated using line graphs. Categorical variables were presented using frequency tables and charts. Eighteen children who underwent baseline KUB and [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 imaging within their first year of life but lacked at least one year of subsequent follow-up were excluded from longitudinal analyses, and missing data were appropriately addressed.\u003c/p\u003e\u003cp\u003ePredictors of MCDK involution were initially explored using the Log Rank (Mantel-Cox) test in bivariate analysis, followed by Cox proportional hazards regression. Cases without evidence of MCDK involution at the end of follow-up were right-censored. In the multivariate regression, 'MCDK involuted' served as the status (dependent) variable and 'year of involution' as the time variable. Predictor variables included initial size of the multicystic dysplastic kidney (\u0026lt;\u0026thinsp;5 cm vs\u0026thinsp;\u0026gt;\u0026thinsp;5 cm), type of MCDK (simple vs complex), gender, presence of contralateral hypertrophy, presence of contralateral abnormality, and laterality; all were entered as categorical covariates in the Cox model using the 'Enter' method. Statistical significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. Data were stored in a password-protected Excel file accessible only to the primary researcher, with the patient identification key maintained separately to ensure confidentiality. Each participant was assigned a unique study number, and no identifying information was included in any research outputs.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003eIncidence of MCDK among children seen in the renal clinic of RCWMCH:\u003c/h2\u003e\u003cp\u003eBetween 1 January 2014 and 31 December 2023, there were 20,569 paediatric renal outpatient clinic visits, including 1,581 new cases. Of these, 101 children were diagnosed with multicystic dysplastic kidney (MCDK) based on postnatal KUB and [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 scans; three cases were excluded due to unavailable records, resulting in 98 confirmed cases with an MCDK incidence of 6.2%. The incidence varied annually, with the lowest rate of 1.5% observed in 2020 and the highest of 10.1% in 2022, as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eDemographic characteristics of study participants (Table )\u003c/h3\u003e\n\u003cp\u003eOf the 98 children diagnosed with unilateral MCDK, 84 (85.7%) were identified antenatally, with Groote Schuur Hospital accounting for 60% of referrals. The cohort had a balanced sex distribution, 49 (50.0%) male, and left-sided involvement in 56 (57.1%). The median age at first renal clinic visit of 1.5 months (IQR 1\u0026ndash;2) for kidney ultrasound and 2 months (IQR 1.5\u0026ndash;3) for a [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 scan. Median follow-up was 36 months (IQR 12\u0026ndash;72). All patients exhibited a non-functioning kidney on [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3, with preserved function in the contralateral kidney.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDemographic characteristics of patients with multicystic dysplastic kidney (MCDK)\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristic\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrequency (n\u0026thinsp;=\u0026thinsp;98)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePercentage (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e50.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e50.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDistribution by age at first clinic visit\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;1 month\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e43.9\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;1 month\u0026thinsp;\u0026le;\u0026thinsp;6 months\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e49.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026ge;\u0026thinsp;6\u0026ndash;12 months\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e6.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDistribution by birthweight\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;2.5Kg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026ge;\u0026thinsp;2.5kg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e94.9\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDiagnosis\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrenatal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e85.7\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostnatal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e14.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePresenting Complaints\u003c/b\u003e \u003csup\u003e\u003cb\u003e$\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFMU scan \u0026ndash; \u0026lsquo;suspected MCDK/cystic kidney\u0026rsquo;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e72.4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAbdominal mass\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSuspected urinary tract infection\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e6.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIncidental finding\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAntenatal hydronephrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e10.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAcute kidney injury\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUnreported\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMCDK side\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e42.9\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e57.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eReferral (n\u0026thinsp;=\u0026thinsp;50)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroote Schuur Hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e60.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMowbray Maternity Hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e12.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrivate hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e12.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVredenburg Hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e6.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGeorge Hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTygerberg Hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNew Somerset Hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2 Military Hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUrology unit\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003csup\u003e$\u003c/sup\u003e Multiple options apply\u003c/p\u003e\u003cp\u003eFMU: Fetomaternal (antenatal) ultrasound\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003ePatterns of associated genitourinary and extrarenal anomalies among children with MCDK (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/h2\u003e\u003cp\u003eContralateral kidney abnormalities were observed in 17 children (17.3%), with duplex kidney being the most common anomaly (33.3%), frequently complicated by reflux and hydronephrosis or hydroureters. Other contralateral anomalies included ureteropelvic junction obstruction (27.8%), hydroureteronephrosis and hydronephrosis (each 11.1%), contralateral dysplasia (11.1%), and vesicoureteric reflux (22.2%). Ipsilateral hydroureters and ureterocoeles were identified in 4.1% of cases. Additionally, 8.2% of children had extra-renal anomalies, equally divided between syndromic and non-syndromic forms.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDistribution of abnormalities of the contralateral kidney on ultrasound and associated extrarenal anomalies\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrequency (n\u0026thinsp;=\u0026thinsp;17/98)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePercent\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAssociated anomalies\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDuplex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Uncomplicated\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33.3%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Complicated\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e66.7%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eo With Reflux alone*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.7\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eo With HU/HN and Reflux*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eo With ureterocoele and HN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUPJO\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27.8\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eUrinary tract dilatation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eHydroureteronephrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydronephrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDysplasia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVUR *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e22.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAssociated abnormalities of the ipsilateral kidney on ultrasound (n\u0026thinsp;=\u0026thinsp;4/98, 4.1%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUreterocoele in bladder\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydroureter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eExtrarenal abnormalities (n\u0026thinsp;=\u0026thinsp;8/98, 8.2%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSyndromic n\u0026thinsp;=\u0026thinsp;4\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCostello syndrome\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4q deletion syndrome\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAlagille\u0026rsquo;s syndrome\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTrisomy 21 with ASD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eNon-syndromic n\u0026thinsp;=\u0026thinsp;4\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCoarctation of Aorta\u0026thinsp;+\u0026thinsp;Cardiomyopathy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydrocolpos\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHemivertebrae (L4/L5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIsolated oesophageal atresia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eUPJO \u0026ndash; ureteropelvic junction obstruction, VUR \u0026ndash; vesicoureteric reflux** on [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 only\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eEstimated glomerular filtration rates, urine and radiology investigations of the study cohort\u003c/h3\u003e\n\u003cp\u003eOf the entire cohort, 81/98 were followed up beyond the first year. Of these, 63 (69.8%) had simple unilateral MCDK, while 18 (25.9%) had complex MCDK. As shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, 15 (18.5%) developed UTIs. One case of UTI was confirmed in the neonatal period. During later follow-up, 14 children (17.3%) experienced UTIs. The baseline median glomerular filtration rate (GFR) was 62 ml/min/1.73 m\u0026sup2; (IQR 35\u0026ndash;82), which increased to 121 ml/min/1.73 m\u0026sup2; (IQR 90\u0026ndash;147) at the last follow-up. Of the 14 children with a recorded eGFR at the final visit, five exhibited hyperfiltration, seven had normal GFRs, and two had persistently reduced GFR (\u0026lt;\u0026thinsp;90 ml/min/1.73 m\u0026sup2;). MCUG were performed in four patients (22.2%) presenting with hydronephrosis, hydroureters, or suspected reflux based on contralateral kidney renogram findings. Of these, one had a dysplastic kidney and three had duplex kidneys; none demonstrated reflux on MCUG.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSerum creatinine, eGFR, urine and serial radiological investigation history of the study cohort\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003eMedian (IQR)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian serum creatinine (\u0026micro;mol/L) at baseline\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003e35.0 (24.5, 64.5)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian serum creatinine (\u0026micro;mol/L) at last visit\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003e33.5 (27.2, 40.25)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian eGFR (ml/min/1.73m\u003csup\u003e2\u003c/sup\u003e ) at baseline (n\u0026thinsp;=\u0026thinsp;21/81)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003e62 (35, 82)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian eGFR (ml/min/1.73m\u003csup\u003e2\u003c/sup\u003e ) at last visit (n\u0026thinsp;=\u0026thinsp;14/81)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003e121 (90, 147)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e\u003cb\u003eFrequency\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e\u003cb\u003ePercent\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUrinary Tract Infections (n\u0026thinsp;=\u0026thinsp;81):\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e18.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAt presentation\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOrganism isolated\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003eEscherichia Coli\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e1.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAt any time\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e17.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eOrganism isolated\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eEscherichia Coli\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e71.4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eKlebsiella spp\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e14.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eProteus spp\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e7.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eCitrobacter spp\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e7.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eImaging\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMCUG done / vesicoureteric reflux absent\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003e4.9% / (100%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian (IQR)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eChanges in KUB characteristic findings\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eBaseline\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eN\u0026thinsp;=\u0026thinsp;81\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e\u003cb\u003e1 year\u003c/b\u003e\u003c/p\u003e\u003cp\u003eN\u0026thinsp;=\u0026thinsp;81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e2 year\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eN\u0026thinsp;=\u0026thinsp;64\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e5 year\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eN\u0026thinsp;=\u0026thinsp;31\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSize of affected kidney (cm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.9\u003c/p\u003e\u003cp\u003e(3.60\u0026ndash;5.95)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e4.1\u003c/p\u003e\u003cp\u003e(2.82\u0026ndash;6.20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4.3\u003c/p\u003e\u003cp\u003e(2.0\u0026ndash;7.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.0\u003c/p\u003e\u003cp\u003e(0.0\u0026ndash;4.0)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSize of contralateral kidney (cm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.5\u003c/p\u003e\u003cp\u003e(5.0\u0026ndash;6.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e6.8\u003c/p\u003e\u003cp\u003e(6.3\u0026ndash;7.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e7.6\u003c/p\u003e\u003cp\u003e(7.38\u0026ndash;8.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e9.0\u003c/p\u003e\u003cp\u003e(8.58\u0026ndash;9.60)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\n\u003ch3\u003eCompensatory hypertrophy of the contralateral kidney\u003c/h3\u003e\n\u003cp\u003eCompensatory hypertrophy of the contralateral kidney was observed in 80.2% of children, with prevalence rising from 7.4% at birth to 80.2% by five years, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eComplications of MCDK among the follow-up cohort of children\u003c/b\u003e: During follow-up, one child (1.2%) developed hypertension, and two children developed chronic kidney disease (eGFR\u0026thinsp;\u0026lt;\u0026thinsp;90 ml/min/1.73 m\u0026sup2;); all had contralateral kidney dysplasia. Additionally, two children exhibited persistent sub-nephrotic proteinuria: one with a duplex kidney and upper tract dilatation, and another with contralateral UPJO and 4q deletion syndrome.\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eInvolution of the MCDK\u003c/h2\u003e\u003cp\u003eFifty-six children (69.1%) exhibited partial or complete regression of the affected kidney. Complete involution was observed at birth in five cases (6.1%), with cumulative rates of 25.9% at one year, 39.5% at two years, and 45.7% at five years, as illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Among the 25 children (30.9%) whose kidneys did not involute, 44.0% showed an increase in size, and 56.0% remained stable. The mean age at involution for kidneys\u0026thinsp;\u0026le;\u0026thinsp;5.0 cm at baseline was 1.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3 years, compared to 2.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4 years for those\u0026thinsp;\u0026gt;\u0026thinsp;5.0 cm. The average initial size was 3.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4 cm in children who involuted, versus 6.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9 cm in those who did not.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003ePredictors of MCDK involution:\u003c/h2\u003e\u003cp\u003eThe Log-Rank (Mantel-Cox) test and Cox proportional hazards regression were employed to identify predictors of MCDK involution, as detailed in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. At the bivariate level, both initial MCDK size (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and compensatory hypertrophy of the contralateral kidney (p\u0026thinsp;=\u0026thinsp;0.03) were significant predictors. The multivariate Cox regression model, which satisfied the proportional hazards assumption and demonstrated good fit (-2 Log Likelihood\u0026thinsp;=\u0026thinsp;445.452; omnibus χ\u0026sup2; (6)\u0026thinsp;=\u0026thinsp;13.290, p\u0026thinsp;=\u0026thinsp;0.039), revealed that only initial kidney size remained significant (p\u0026thinsp;=\u0026thinsp;0.005; HR\u0026thinsp;=\u0026thinsp;2.425, 95% CI: 1.311\u0026ndash;4.485) for predicting involution. Specifically, children with an initial MCDK size of \u0026le;\u0026thinsp;5.0 cm were more than twice as likely to undergo involution over time compared to those with larger initial sizes. Covariate coding and hazard ratios are presented in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePredictors of involution of MCDK\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eInvolution present\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eInvolution absent\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBivariate analysis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003eMultivariate Analysis\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eLog-rank\u003c/p\u003e\u003cp\u003e(Mantel-Cox)\u003c/p\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003eCox Proportional Regression\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eHR (95% CI)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eType of MCDK\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.626\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.831\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.930 (0.478\u0026ndash;1.809)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSimple\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44 (69.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19 (30.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComplex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12 (66.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 (33.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eGender\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.330\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.539\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.840 (0.481\u0026ndash;1.466)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e30 (75.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10 (25.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e26 (63.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15 (36.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCompensatory hypertrophy\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.030*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.057\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.181 (0.977\u0026ndash;4.867)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e49 (75.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16 (24.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7 (43.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9 (56.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean Kidney size (initial)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.970 (0.954\u0026ndash;0.986) **\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eKidney Size (\u0026le;\u0026thinsp;5.0cm)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.002*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.425 (1.311\u0026ndash;4.485) **\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e39 (81.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9 (18.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17 (51.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16 (48.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTime at diagnosis\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.422\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.222\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.474 (0.791\u0026ndash;2.746)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAntenatal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e41 (71.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16 (28.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostnatal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15 (62.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9 (37.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eContralateral abnormality\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.626\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.831\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.930 (0.478\u0026ndash;1.809)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12 (66.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 (33.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44 (68.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19 (30.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLaterality of MCDK\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.346\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.899\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.037 (0.589\u0026ndash;1.825)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (63.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13 (36.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e33 (73.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12 (26.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e\u003cp\u003e* / ** statistically significant in bivariate and multivariate analysis\u003c/p\u003e\u003cp\u003et-test statistic 7.1652 mean difference: -2.40; (95% CI; \u0026minus;\u0026thinsp;3.067 to \u0026ndash; 1.733)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eSurgical and follow-up outcomes\u003c/strong\u003e\u003cp\u003eDuring follow-up, three children (3.7%) required surgery; one nephrectomy for persistently increasing MCDK\u0026thinsp;\u0026gt;\u0026thinsp;10 cm with intra-abdominal compromise and two had pyeloplasty for contralateral obstruction. At the last clinic visit, 56.8% remained under follow-up, 12.3% had transitioned to adolescent care, 2.5% were transferred out, and 28.4% were lost to follow-up. No malignancies or MCDK-related deaths were observed.\u003c/p\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study described the epidemiology of paediatric MCDK as seen in a tertiary specialist renal outpatient clinic in sub-Saharan Africa. MCDK, typically identified in either the perinatal or postnatal period, has a reported incidence of 1 in 2,200 to 4,300 live births [2,3]. However, these estimates were derived exclusively from data outside sub-Saharan Africa. The apparent underdiagnosis of MCDK in this region may plausibly reflect both limited detection and genetic variability. In our cohort, MCDK accounted for approximately 1 in 16 new renal cases seen at the outpatient clinic during the study period, making it the most common cystic dysplastic kidney disease observed. By comparison, an earlier study by Lala[19] identified 59 cases among 10,445 admissions over 30 years in Johannesburg, corresponding to a prevalence of 5.7 per 1,000 admissions, although differences in denominators limit direct comparison. Notably, our findings demonstrate an increasing incidence of MCDK over the past decade, which may be attributable to enhanced expertise in feto-maternal ultrasonography, improvements in ultrasound technology, and our role as a regional referral centre. Accurately assessing the incidence of MCDK is challenging due to its often-asymptomatic presentation until later life [33]. In South Africa, the lack of multicentre or nationwide registries for CAKUT surveillance precludes reliable regional estimates. Furthermore, the observed reduction in incidence in 2020 is most likely a consequence of reduced healthcare access during the COVID-19 pandemic.\u003c/p\u003e\u003cp\u003eThe predominance of prenatal ultrasound diagnoses in this cohort signifies progress in early MCDK detection relative to an earlier South African finding [19]. Referrals primarily originated from tertiary centres, indicating improved diagnostic precision attributable to technological advancements and consensus guidelines. Most cases were identified during third-trimester scans, consistent with reports from Spain [34] and a recent meta-analysis by Erlich and colleagues [35]. Furthermore, contemporary studies demonstrate that prenatal diagnostic accuracy for MCDK has reached rates as high as 91.3 \u0026minus;\u0026thinsp;98.0% [14,33,36,37], underscoring the increasing effectiveness of prenatal ultrasound in this context.\u003c/p\u003e\u003cp\u003eApproximately one-fifth of children in this cohort exhibited contralateral kidney abnormalities, consistent with the reported range of 5\u0026ndash;43% in other studies [21], though lower than the 33% pooled estimate from the meta-analysis by Schreuder and colleagues.\u003csup\u003e3\u003c/sup\u003e Vesicoureteric reflux (VUR) is frequently cited as the most common abnormality, with pooled rates of 17\u0026ndash;20% [3,35]. However, it was not reflected in our cohort. Notably, reflux was detected by [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 renogram in a small number of cases, but not confirmed by MCUG, as previously observed in South African studies [19,38]. This finding underpins the selective use of MCUG, reserving it for cases with contralateral or bladder abnormalities on kidney ultrasound scan, rather than routine application in all children with MCDK.\u003c/p\u003e\u003cp\u003eOur study found duplex kidney to be the most common contralateral abnormality, observed in one-third of affected cases, a finding scarcely reported in other studies. Particularly, kidney duplication was not identified as an abnormality in earlier systematic reviews [3,35], with only sporadic reports documenting such findings [39,40].\u003c/p\u003e\u003cp\u003eUreteropelvic junction obstruction was the second most frequent contralateral anomaly, with a subset of patients requiring surgical intervention to preserve kidney function. Ipsilateral abnormalities were rare, affecting less than a tenth of the cohort, markedly lower than the prevalence reported in other studies [33,41,42]. The primary ipsilateral findings were ureterocoeles and hydroureters, whereas previous studies have also described vesicoureteral reflux and internal genital tract anomalies [41,42].\u003c/p\u003e\u003cp\u003eConsistent with the literature, this study found that approximately 1 in 10 children with MCDK had extra-renal anomalies, including rare syndromic associations suggestive of a possible genetic component in some cases [43\u0026ndash;46]. Although the prevalence of extrarenal associations in our cohort was lower than previously reported rates of 25\u0026ndash;48% [37,47] these findings emphasise the importance of thorough physical examination in children with MCDK.\u003c/p\u003e\u003cp\u003eCompensatory hypertrophy of the contralateral kidney is well-documented in MCDK and is associated with involution of the affected kidney after two years of age [48]. In this study, compensatory hypertrophy was observed in less than one-tenth of children at birth, increasing to four-fifths by five years, consistent with previous reports of rapid early growth in the functional kidney[5,9,14,15,49\u0026ndash;51]. However, about one-fifth of our cohort did not develop compensatory hypertrophy, highlighting the need for ongoing surveillance, as the absence of hypertrophy may indicate underlying kidney dysfunction [27].\u003c/p\u003e\u003cp\u003eStudies have reported on the involution rates of MCDK over time, with approximately 5\u0026ndash;6% showing complete involution at birth [3], a finding mirrored in this study. Our cohort demonstrated cumulative involution probabilities, aligning with international data [4,22,34,52,53]. Variations in involution rates across studies may reflect differences in follow-up duration, sample size, and scan quality. Consistent with earlier studies, an initial MCDK size of \u0026le;\u0026thinsp;5 cm was found to be a positive predictor of complete involution [4,8,53]\u003c/p\u003e\u003cp\u003eAt presentation, most children had low eGFRs, reflecting immature kidney function due to young age. Only a subset of patients had follow-up eGFR measured, with median values increasing to normal levels and some demonstrating hyperfiltration without proteinuria. Two children developed CKD, both with complex contralateral abnormalities and no involution of the affected kidney. These findings align with previous studies highlighting variability in kidney function and proteinuria among children with MCDK. [22,53,54]. Furthermore, our findings buttress the necessity for baseline and annual monitoring of kidney function and proteinuria to detect early signs of kidney injury, regardless of perceived risk. Given the potential for hyperfiltration and the implications of Brenner\u0026rsquo;s and Barker\u0026rsquo;s hypotheses, children with MCDK, particularly those with low birth weight or complex type disease, may require long-term surveillance and lifestyle counselling to mitigate future cardiometabolic and chronic kidney risks [9,55].\u003c/p\u003e\u003cp\u003eAt the last follow-up clinic visit, most children with MCDK remained under surveillance, while a proportion had been transferred to adolescent care or to facilities outside Cape Town. Notably, nearly one-quarter of the cohort were lost to follow-up, a trend potentially attributed to caregiver reassurance following favourable prognoses, a phenomenon previously observed in another study [56]. This is concerning, given the enduring risk of chronic kidney disease, as evidenced by the Solitary Functioning Kidney: Aetiology and Prognosis (SOFIA) study, which reported that a substantial proportion of patients with a solitary functioning kidney exhibited markers of kidney injury by late adolescence [11]. Even in children with unilateral MCDK and a normal contralateral kidney, the risk of developing stage II CKD remains appreciable by age ten [50,55,57]. These findings highlight the necessity of thorough education for caregivers regarding long-term renal risks and highlight the importance of implementing strategies to improve follow-up adherence.\u003c/p\u003e\u003cp\u003eNo cases of malignancy, mortality, or need for kidney replacement therapy were reported over the study period. Conservative management, involving serial ultrasonography until spontaneous involution, proved effective, offering reduced procedural risks and financial savings, as similarly noted in earlier studies.\u003csup\u003e12,21\u003c/sup\u003e The optimal frequency of kidney ultrasound scan monitoring remains contentious, with protocols ranging from intensive early follow-up to interval-based surveillance at key developmental milestones [16,22,54,55,58]. In light of this cohort\u0026rsquo;s largely benign short-term outcomes, adopting a less intensive follow-up regimen, including kidney ultrasound scans at birth, one month, two years, five years, and ten years, respectively, as suggested by Hains et al.[21] and Aslam et al.[22], appears appropriate for the present study\u0026rsquo;s setting. We suggest this approach because our protocol of a more frequent follow-up regimen did not necessarily improve clinical follow-up compliance.\u003c/p\u003e\u003cp\u003eTherefore, this study demonstrates that paediatric MCDK can be accurately diagnosed, monitored, and managed conservatively in resource-constrained settings. Moreover, reducing the number of clinic appointments could enhance patient compliance with follow-up visits and alleviate pressure on the already overburdened healthcare system.\u003c/p\u003e\u003cp\u003eThis single-centre study was constrained by its retrospective design, with some incomplete or missing data, variability in the documentation of clinical notes and laboratory test requests, which could potentially impact the reliability and generalisability of the findings and introduce possible bias.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study found that most children with MCDK experience favourable short-term outcomes, particularly in the absence of contralateral abnormalities. However, a considerable subset presented with duplex kidneys, lacked compensatory hypertrophy, or showed no involution, underscoring the need for continued surveillance. Closer monitoring may be warranted for certain groups, including preterm neonates, those with initial kidney sizes exceeding 5 cm, complex contralateral abnormalities, and those children with either increasing or non-regressing MCDK sizes suggesting maladaptive compensation.\u003c/p\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e for this study was granted by the Human Research Ethics Committee of the University of Cape Town (HREC:805/2024) and the ethics committee of the Red Cross War Memorial Hospital (RXH: RCC 451/WC_220410_034). Due to the retrospective nature of the study, a waiver of parental consent was also approved by the Institutional Ethics Committees (HREC:805/2024). The study was conducted in accordance with the Declaration of Helsinki.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003edata will be made available on reasonable request and ethical approval of the institution.\u003cstrong\u003e\u0026nbsp;\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding: none\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/strong\u003eConceptualisation: [Asthon Coetzee, Mignon McCulloch, Anita Brink, Peter Nourse, Datonye Briggs]; Methodology: [Datonye Briggs, Ashton Coetzee, Khanyisile Hlongwa]; Formal analysis and investigation: [Datonye Briggs], Writing - original draft preparation: [Datonye Briggs]; Writing - review and editing: [Datonye Briggs, Ashton Coetzee, Khanyisile Hlongwa, Anita Brink, Peter Nourse, Mignon McCulloch], Supervision: [Ashton Coetzee (lead), Khanyisile Hlongwa]. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eThe authors acknowledge the International Society of Nigeria (ISN) and the International PNA for making the training of the first / corresponding Author possible.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eEmma F, Goldstein SL, Bagga A, Bates CM, Shroff R, eds. \u003cem\u003ePediatric Nephrology\u003c/em\u003e. Springer International Publishing; 2022. doi:10.1007/978-3-030-52719-8\u003c/li\u003e\n\u003cli\u003eDillon E, Ryall A. A 10 year audit of antenatal ultrasound detection of renal disease. \u003cem\u003eThe British Journal of Radiology\u003c/em\u003e. 1998;71(845):497-500. doi:10.1259/bjr.71.845.9691894\u003c/li\u003e\n\u003cli\u003eSchreuder MF, Westland R, Van Wijk JAE. Unilateral multicystic dysplastic kidney: a meta-analysis of observational studies on the incidence, associated urinary tract malformations and the contralateral kidney. \u003cem\u003eNephrology Dialysis Transplantation\u003c/em\u003e. 2009;24(6):1810-1818. doi:10.1093/ndt/gfn777\u003c/li\u003e\n\u003cli\u003eEickmeyer AB, Casanova NF, He C, et al. The natural history of the multicystic dysplastic kidney \u0026ndash; Is limited follow-up warranted? \u003cem\u003eJournal of Pediatric Urology\u003c/em\u003e. 2014;10(4):655-661. doi:10.1016/j.jpurol.2014.06.001\u003c/li\u003e\n\u003cli\u003eGaither TW, Patel A, Patel C, Chuang K wen, Cohen RA, Baskin LS. Natural History of Contralateral Hypertrophy in Patients with Multicystic Dysplastic Kidneys. \u003cem\u003eJournal of Urology\u003c/em\u003e. 2018;199(1):280-286. doi:10.1016/j.juro.2017.06.075. \u003c/li\u003e\n\u003cli\u003eCambio AJ, Evans CP, Kurzrock EA. Non-surgical management of multicystic dysplastic kidney. \u003cem\u003eBJU Int\u003c/em\u003e. 2008;101(7):804-808. doi:10.1111/j.1464-410X.2007.07328.x\u003c/li\u003e\n\u003cli\u003eUnilateral multicystic dysplastic kidney: does initial size matter? \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2012;27(8):1335-1340. doi:10.1007/s00467-012-2141-9\u003c/li\u003e\n\u003cli\u003eSarhan OM, Alghanbar M, Alsulaihim A, Alharbi B, Alotay A, Nakshabandi Z. Multicystic dysplastic kidney: Impact of imaging modality selection on the initial management and prognosis. \u003cem\u003eJournal of Pediatric Urology\u003c/em\u003e. 2014;10(4):645-649. doi:10.1016/j.jpurol.2014.03.004\u003c/li\u003e\n\u003cli\u003eMansoor O, Chandar J, Rodriguez MM, et al. Long-term risk of chronic kidney disease in unilateral multicystic dysplastic kidney. \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2011;26(4):597-603. doi:10.1007/s00467-010-1746-0\u003c/li\u003e\n\u003cli\u003eDogan SC, Bayram TM, Aybar MS. Unilateral multicystic dysplastic kidney in children. \u003cem\u003eThe Turkish Journal of Pediatrics\u003c/em\u003e. 2014;56:75-79. PMID: 24827951.\u003c/li\u003e\n\u003cli\u003eGroen In \u0026rsquo;T Woud S, Westland R, Feitz WFJ, et al. Clinical Management of Children with a Congenital Solitary Functioning Kidney: Overview and Recommendations. \u003cem\u003eEuropean Urology Open Science\u003c/em\u003e. 2021;25:11-20. doi:10.1016/j.euros.2021.01.003\u003c/li\u003e\n\u003cli\u003eChang A, Sivananthan D, Nataraja RM, Johnstone L, Webb N, Lopez PJ. Evidence-based treatment of multicystic dysplastic kidney: a systematic review. \u003cem\u003eJournal of Pediatric Urology\u003c/em\u003e. 2018;14(6):510-519. doi:10.1016/j.jpurol.2018.09.018\u003c/li\u003e\n\u003cli\u003eFeldenberg LR, Siegel NJ. Clinical course and outcome for children with multicystic dysplastic kidneys. \u003cem\u003ePediatric Nephrology\u003c/em\u003e. 2000;14(12):1098-1101. doi:10.1007/s004670000391\u003c/li\u003e\n\u003cli\u003eMoralioglu S, Celayir AC, Bosnali O, Pektas OZ, Bulut IK. Single center experience in patients with unilateral multicystic dysplastic kidney. \u003cem\u003eJ Pediatr Urol\u003c/em\u003e. 2014;10(4):763-768. doi:10.1016/j.jpurol.2014.03.008\u003c/li\u003e\n\u003cli\u003eAkbalik Kara M, Taktak A, Alparslan C. Retrospective evaluation of the pediatric multicystic dysplastic kidney patients: experience of two centers from southeastern Turkey. \u003cem\u003eTurk J Med Sci\u003c/em\u003e. 2021;51(3):1331-1337. doi:10.3906/sag-2011-175\u003c/li\u003e\n\u003cli\u003eGrabnar J, Rus RR. Is renal scintigraphy really a necessity in the routine diagnosis of congenital solitary kidney? \u003cem\u003ePediatr Surg Int\u003c/em\u003e. 2019;35(6):729-735. doi:10.1007/s00383-019-04478-1\u003c/li\u003e\n\u003cli\u003eChaki S, Mclarty R, Mzolo I, Rajan S, Chipongo H. A Rare Case of Antenatal Bilateral Multicystic Dysplastic Kidney Disease: An Unusual Presentation in a Neonate. \u003cem\u003eClinical Case Reports\u003c/em\u003e. 2025;13(4):e70407. doi:10.1002/ccr3.70407\u003c/li\u003e\n\u003cli\u003eMusa A, Umar L, Bugaje M, Rosamund A. Multicystic dysplastic kidney with associated contralateral renal ectopia in an infant: A rare association. \u003cem\u003eSub-Saharan Afr J Med\u003c/em\u003e. 2016;3(2):122. doi:10.4103/2384-5147.184381\u003c/li\u003e\n\u003cli\u003eNilesh L. \u003cem\u003eMulticystic Dysplastic Kidney Disease at Chris Hani Baragwanath Academic Hospital over a Thirty Year Period\u003c/em\u003e. University of Witwatersrand; 2017.\u003c/li\u003e\n\u003cli\u003eOkoronkwo NC, Levy C, Khumalo T, Moonsamy G. Congenital anomalies of the kidney and the urinary tract in a South African paediatric nephrology setting. \u003cem\u003eSouth African Journal of Child Health\u003c/em\u003e. 2020;14(1):40-44. doi:10.7196/SAJCH.2020.v14.i1.01666\u003c/li\u003e\n\u003cli\u003eHains DS, Bates CM, Ingraham S, Schwaderer AL. Management and etiology of the unilateral multicystic dysplastic kidney: a review. \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2009;24(2):233-241. doi:10.1007/s00467-008-0828-8\u003c/li\u003e\n\u003cli\u003eAslam M. Unilateral multicystic dysplastic kidney: long term outcomes. \u003cem\u003eArchives of Disease in Childhood\u003c/em\u003e. 2006;91(10):820-823. doi:10.1136/adc.2006.095786\u003c/li\u003e\n\u003cli\u003eJawa NA, Rosenblum ND, Radhakrishnan S, Pearl RJ, Levin L, Matsuda-Abedini M. Reducing Unnecessary Imaging in Children With Multicystic Dysplastic Kidney or Solitary Kidney. \u003cem\u003ePediatrics\u003c/em\u003e. 2021;148(2):e2020035550. doi:10.1542/peds.2020-035550\u003c/li\u003e\n\u003cli\u003eStuck KJ, Koff SA, Silver TM. Ultrasonic features of multicystic dysplastic kidney: expanded diagnostic criteria. \u003cem\u003eRadiology\u003c/em\u003e. 1982;143(1):217-221. doi:10.1148/radiology.143.1.7063729\u003c/li\u003e\n\u003cli\u003eLebowitz RL, Olbing H, Parkkulainen KV, Smellie JM, Tamminen-M\u0026ouml;bius TE. International system of radiographic grading of vesicoureteric reflux. \u003cem\u003ePediatr Radiol\u003c/em\u003e. 1985;15(2):105-109. doi:10.1007/BF02388714\u003c/li\u003e\n\u003cli\u003eChoi YH, Cheon JE, Kim WS, Kim IO. Ultrasonography of hydronephrosis in the newborn: a practical review. \u003cem\u003eUltrasonography\u003c/em\u003e. 2016;35(3):198-211. doi:10.14366/usg.15073\u003c/li\u003e\n\u003cli\u003eWang MK, Gaither T, Phelps A, Cohen R, Baskin L. The Incidence and Durability of Compensatory Hypertrophy in Pediatric Patients with Solitary Kidneys. \u003cem\u003eUrology\u003c/em\u003e. 2019;129:188-193. doi:10.1016/j.urology.2019.04.003\u003c/li\u003e\n\u003cli\u003eBiassoni L, Gordon I. Radioisotope imaging of the kidney and urinary tract. In: \u003cem\u003ePediatric Urology\u003c/em\u003e. Elsevier; 2010:108-126. doi:10.1016/B978-1-4160-3204-5.00008-6\u003c/li\u003e\n\u003cli\u003eFlynn JT, Kaelber DC, Baker-Smith CM, et al. Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. \u003cem\u003ePediatrics\u003c/em\u003e. 2017;140(3):e20171904. doi:10.1542/peds.2017-1904\u003c/li\u003e\n\u003cli\u003eSchwartz GJ, Mu\u0026ntilde;oz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. \u003cem\u003eJ Am Soc Nephrol\u003c/em\u003e. 2009;20(3):629-637. doi:10.1681/ASN.2008030287\u003c/li\u003e\n\u003cli\u003eHuang Y, Yang X, Zhang Y, et al. Correlation of urine protein/creatinine ratios to 24-h urinary protein for quantitating proteinuria in children. \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2020;35(3):463-468. doi:10.1007/s00467-019-04405-5\u003c/li\u003e\n\u003cli\u003eStevens PE, Ahmed SB, Carrero JJ, et al. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. \u003cem\u003eKidney International\u003c/em\u003e. 2024;105(4):S117-S314. doi:10.1016/j.kint.2023.10.018\u003c/li\u003e\n\u003cli\u003eUrisarri A, Gil M, Mandi\u0026aacute; N, et al. Retrospective study to identify risk factors for chronic kidney disease in children with congenital solitary functioning kidney detected by neonatal renal ultrasound screening. \u003cem\u003eMedicine\u003c/em\u003e. 2018;97(32):e11819. doi:10.1097/MD.0000000000011819\u003c/li\u003e\n\u003cli\u003eCarazo-Palacios ME, Couselo-Jerez M, Serrano-Durb\u0026aacute; A, et al. Multicystic dysplastic kidney: Assessment of the need for renal scintigraphy and the safety of conservative treatment. \u003cem\u003eActas Urol\u0026oacute;gicas Espa\u0026ntilde;olas (English Edition)\u003c/em\u003e. 2017;41(1):62-67. doi:10.1016/j.acuroe.2016.11.004\u003c/li\u003e\n\u003cli\u003eErlich T, Lipsky AM, Braga LH. A meta-analysis of the incidence and fate of contralateral vesicoureteral reflux in unilateral multicystic dysplastic kidney. \u003cem\u003eJournal of Pediatric Urology\u003c/em\u003e. 2019;15(1):77.e1-77.e7. doi:10.1016/j.jpurol.2018.10.023\u003c/li\u003e\n\u003cli\u003eScala C, McDonnell S, Murphy F, et al. Diagnostic accuracy of midtrimester antenatal ultrasound for multicystic dysplastic kidneys. \u003cem\u003eUltrasound in Obstet \u0026amp;amp; Gyne\u003c/em\u003e. 2017;50(4):464-469. doi:10.1002/uog.17305\u003c/li\u003e\n\u003cli\u003eAlamir A, Al Rasheed SA, Al Qahtani AT, et al. The Outcome of Multicystic Dysplastic Kidney Disease Patients at King Abdulaziz Medical City in Riyadh. \u003cem\u003eCureus\u003c/em\u003e. Published online April 22, 2023. doi:10.7759/cureus.37994\u003c/li\u003e\n\u003cli\u003eKala UK, Jacobs DWC. Evaluation of urinary tract infection in malnourished black children. \u003cem\u003eAnnals of Tropical Paediatrics\u003c/em\u003e. 1992;12(1):75-81. doi:10.1080/02724936.1992.11747549\u003c/li\u003e\n\u003cli\u003eNugraha HG, Adibrata ASP. Unilateral multicystic dysplastic kidney disease associated with ipsilateral ureteric bud remnant and contralateral duplex collecting system. \u003cem\u003eRadiology Case Reports\u003c/em\u003e. 2023;18(6):2289-2292. doi:10.1016/j.radcr.2023.03.048\u003c/li\u003e\n\u003cli\u003eChun-Chen L, Jeng-Daw T, Jin-Cherng S, Hsiang-Ju L, Brian Pin-Hsuan C. Segmental multicystic dysplastic kidney in children: clinical presentation, imaging finding, management, and outcome. \u003cem\u003eJournal of Pediatric Surgery\u003c/em\u003e. 2010;45(9):1856-1862. doi:10.1016/j.jpedsurg.2010.03.028\u003c/li\u003e\n\u003cli\u003eMerrot T, Lumenta DB, Tercier S, Morisson-Lacombes G, Guys JM, Alessandrini P. Multicystic dysplastic kidney with ipsilateral abnormalities of genitourinary tract: experience in children. \u003cem\u003eUrology\u003c/em\u003e. 2006;67(3):603-607. doi:10.1016/j.urology.2005.09.062\u003c/li\u003e\n\u003cli\u003eMathiot A, Liard A, Eurin D, Dacher JN. Prenatally detected multicystic renal dysplasia and associated anomalies of the genito-urinary tract. \u003cem\u003eJ Radiol\u003c/em\u003e. 2002;83(6 Pt 1):731-735.\u003c/li\u003e\n\u003cli\u003eTeles-Silva C, Martins F, Costa S, et al. Renal Dysplasia and Progressive Renal Failure in a Newborn with Interstitial Chromosome 4 Deletion 4q25-28.3: A New Phenotype? \u003cem\u003eJ Pediatr Genet\u003c/em\u003e. 2021;10(01):039-044. doi:10.1055/s-0039-1701043\u003c/li\u003e\n\u003cli\u003eMartin SR, Garel L, Alvarez F. Alagille\u0026rsquo;s syndrome associated with cystic renal disease. \u003cem\u003eArch Dis Child\u003c/em\u003e. 1996;74(3):232-235. doi:10.1136/adc.74.3.232\u003c/li\u003e\n\u003cli\u003eOzunan Akil I, Evrengul H, Cetin M, Taneli C. Renal ve \u0026Uuml;rolojik Bulgular Costello Sendromu ile Iliskili midir? Is Renal and Urologic Findings Associated with Costello Syndrome?: Case Repor. \u003cem\u003eTurkiye Klinikleri J Pediatr\u003c/em\u003e. 2013;22(2):78-82.\u003c/li\u003e\n\u003cli\u003eHoffman JD, Bianchi DW, Sullivan LM, et al. Down syndrome serum screening also identifies an increased risk for multicystic dysplastic kidney, two-vessel cord, and hydrocele. \u003cem\u003ePrenatal Diagnosis\u003c/em\u003e. 2008;28(13):1204-1208. doi:10.1002/pd.2082\u003c/li\u003e\n\u003cli\u003eChetty S. Multicystic dysplastic kidney. \u003cem\u003eAmerican Journal of Obstetrics and Gynecology\u003c/em\u003e. 2021;225(5):B21-B22. doi:10.1016/j.ajog.2021.06.046\u003c/li\u003e\n\u003cli\u003eMcArdle Z, Schreuder MF, Moritz KM, Denton KM, Singh RR. Physiology and Pathophysiology of Compensatory Adaptations of a Solitary Functioning Kidney. \u003cem\u003eFront Physiol\u003c/em\u003e. 2020;11:725. doi:10.3389/fphys.2020.00725\u003c/li\u003e\n\u003cli\u003eSingh JK, Kanojia RP, Narasimhan KL. Multicystic dysplastic kidney in children \u0026mdash; A need for conservative and long term approach. \u003cem\u003eIndian J Pediatr\u003c/em\u003e. 2009;76(8):809-812. doi:10.1007/s12098-009-0117-y\u003c/li\u003e\n\u003cli\u003eJohn U, Rudnik-Sch\u0026ouml;neborn S, Zerres K, Misselwitz J. Kidney growth and renal function in unilateral multicystic dysplastic kidney disease. \u003cem\u003ePediatric Nephrology\u003c/em\u003e. 1998;12(7):567-571. doi:10.1007/s004670050506\u003c/li\u003e\n\u003cli\u003eAlaygut D, Soylu A, Kasap B, T\u0026uuml;rkmen M, \u0026Ccedil;akmakci H, Kavukcu S. The Relationships Between Renal Compensatory Hypertrophy Etiologic Factors and Anthropometric Development in the Pediatric Age Group. \u003cem\u003eUrology\u003c/em\u003e. 2013;82(2):442-447. doi:10.1016/j.urology.2013.03.024\u003c/li\u003e\n\u003cli\u003eKopac M, Kordic R. Associated Anomalies and Complications of Multicystic Dysplastic Kidney. \u003cem\u003ePediatric Reports\u003c/em\u003e. 2022;14(3):375-379. doi:10.3390/pediatric14030044\u003c/li\u003e\n\u003cli\u003eHayes WN, Watson AR, Trent \u0026amp; Anglia MCDK Study Group. Unilateral multicystic dysplastic kidney: does initial size matter? \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2012;27(8):1335-1340. doi:10.1007/s00467-012-2141-9\u003c/li\u003e\n\u003cli\u003eSharada S, Vijayakumar M, Nageswaran P, Ekambaram S, Udani A. Multicystic dysplastic kidney: A retrospective study. \u003cem\u003eIndian Pediatr\u003c/em\u003e. 2014;51(8):641-643. doi:10.1007/s13312-014-0467-z\u003c/li\u003e\n\u003cli\u003eSchreuder MF. Life with one kidney. \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2018;33(4):595-604. doi:10.1007/s00467-017-3686-4\u003c/li\u003e\n\u003cli\u003eDamen-Elias HAM, Stoutenbeek PH, Visser GHA, Nikkels PGJ, De Jong TPVM. Concomitant anomalies in 100 children with unilateral multicystic kidney. \u003cem\u003eUltrasound in Obstet \u0026amp; Gyne\u003c/em\u003e. 2005;25(4):384-388. doi:10.1002/uog.1851\u003c/li\u003e\n\u003cli\u003eMashat SD, El-Desoky SM, Abdulaziz Kari J. Outcome of Multi-Cystic Dysplastic Kidneys in Children. \u003cem\u003eIran J Pediatr\u003c/em\u003e. 2015;25(5):e2991. doi:10.5812/ijp.2991\u003c/li\u003e\n\u003cli\u003eHsu PY, Yu CH, Lin K, Cheng YC, Chang CH, Chang FM. Prenatal diagnosis of fetal multicystic dysplastic kidney in the era of three-dimensional ultrasound: 10-year experience. \u003cem\u003eTaiwanese Journal of Obstetrics and Gynecology\u003c/em\u003e. 2012;51(4):596-602. doi:10.1016/j.tjog.2012.09.015\u003c/li\u003e\n\u003c/ol\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":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-nephrology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bnep","sideBox":"Learn more about [BMC Nephrology](http://bmcnephrol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bnep/default.aspx","title":"BMC Nephrology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Chronic Kidney Disease, Multicystic Dysplastic Kidney, Paediatrics, Epidemiology, Solitary Kidney","lastPublishedDoi":"10.21203/rs.3.rs-7706913/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7706913/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction:\u003c/h2\u003e\u003cp\u003eMulticystic dysplastic kidney disease (MCDK) is a notable congenital anomaly of the kidney and urinary tract, with potential risk for chronic kidney disease, yet data from sub-Saharan Africa remain scarce. This study examined the pattern of MCDK, associated contralateral kidney abnormalities, determined the predictors of MCDK involution and assessed short-term outcomes in children followed beyond one year.\u003c/p\u003e\u003ch2\u003eMethod\u003c/h2\u003e\u003cp\u003eThis retrospective study involved children under 13 years of age with suspected unilateral MCDK, confirmed on kidney ultrasound and [\u003csup\u003e99m\u003c/sup\u003eTc]Tc-MAG3 scans at the Red Cross War Memorial Children's Hospital between January 1, 2014, and December 31, 2023. Demographic, clinical, and radiologic data were obtained. The Log-rank test and Cox Proportional Hazards regression analyses were used to identify predictors of MCDK involution. Ethical approval (HREC REF: 805/2024).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eAmong 1,581 new cases, 98 (6.2%) had unilateral MCDK. Fifty percent were male, and 57.1% had left-sided involvement. Median follow-up was 36 months (IQR: 12\u0026ndash;72). Contralateral kidney abnormalities occurred in 17 (17.3%), most commonly duplex kidney (33.3%) and ureteropelvic junction obstruction (27.8%), but no vesicoureteric reflux was noted. Of 81 children followed beyond a year, 80.2% demonstrated contralateral hypertrophy, and 69.1% exhibited involution of the affected kidney. Initial kidney size\u0026thinsp;\u0026le;\u0026thinsp;5.0cm was the sole predictor of involution (HR: 2.42, 95% CI: 1.31\u0026ndash;4.48). Urinary tract infections occurred in (18.5%), proteinuria in (2.5%), hypertension (1.2%) and 2.5% developed chronic kidney disease related to contralateral dysplasia. One nephrectomy was performed, and no malignancies or deaths. At last follow-up, 12.3% had transitioned to adolescent clinics.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eAll MCDK cases were unilateral, with duplex kidney being the most common contralateral abnormality, a distinctive finding in our cohort. Follow-up into adolescence may be beneficial, as progression of chronic kidney disease is rare in those without contralateral anomalies. Multicentre long-term studies are needed to provide standardised follow-up guidelines.\u003c/p\u003e","manuscriptTitle":"Paediatric Multicystic Dysplastic Kidney Disease in Cape Town, South Africa","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-30 11:52:28","doi":"10.21203/rs.3.rs-7706913/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-11-06T10:46:51+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"32089403359065933823243177685571128933","date":"2025-10-27T04:43:45+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-24T18:39:49+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-22T10:35:31+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-20T04:27:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"167442495187548432068350869429836070329","date":"2025-10-16T14:13:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"75937631103454855109795409918283602526","date":"2025-10-16T03:07:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"203567667263028570914606735968200671485","date":"2025-10-16T01:25:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"203697862573023551008821785124700301604","date":"2025-10-16T00:39:26+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-16T00:37:12+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-16T00:31:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-10-07T09:28:57+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-03T15:57:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Nephrology","date":"2025-10-03T15:53:28+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-nephrology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bnep","sideBox":"Learn more about [BMC Nephrology](http://bmcnephrol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bnep/default.aspx","title":"BMC Nephrology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"91e54e36-7056-4f38-8192-689dec341693","owner":[],"postedDate":"October 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-01T16:07:49+00:00","versionOfRecord":{"articleIdentity":"rs-7706913","link":"https://doi.org/10.1186/s12882-025-04667-2","journal":{"identity":"bmc-nephrology","isVorOnly":false,"title":"BMC Nephrology"},"publishedOn":"2025-11-29 15:58:23","publishedOnDateReadable":"November 29th, 2025"},"versionCreatedAt":"2025-10-30 11:52:28","video":"","vorDoi":"10.1186/s12882-025-04667-2","vorDoiUrl":"https://doi.org/10.1186/s12882-025-04667-2","workflowStages":[]},"version":"v1","identity":"rs-7706913","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7706913","identity":"rs-7706913","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}