Antenatal hydronephrosis and the risk of pyelonephritis hospitalization during the first year of life

Isolated Hydronephrosis and Urinary Tract Infection by Two Years of Age: A Population-Based Study

OBJECTIVE

To evaluate the risk for urinary tract infection (UTI) in infants with isolated hydronephrosis (IH).

STUDY DESIGN

A retrospective, population-based study including all infants insured by Clalit Health Services and followed from birth to age 2 years in 3 regions of central Israel. Infants were divided into 3 groups based on electronic medical record diagnoses by age 6 months: (1) control: no urological diagnosis; (2) IH; and (3) complicated urological diagnosis (CUD): any additional nephrological/urological diagnosis with/without HN. The primary outcome was a diagnosis of UTI in the first 2 years of life.

RESULTS

The cohort included 340 619 infants (52% male): 333 920 controls, 4369 with IH, and 2331 with CUD. Infants with IH were associated with a greater risk for UTI than control patients (17% vs 4%, P < .001). UTI risk for a male infant with IH was greater than for a female infant in the control group (12.6% vs 6.5%, P < .001). In a multivariable logistic regression analysis, both IH (OR 7.04; 95% CI 6.46-7.66) and CUD (OR 14.9; 95% CI 13.6-16.4) were independently associated with UTI.

CONCLUSION

Infants with IH are at a greater risk for UTI in the first 2 years of life, supporting the recommendation for a high index of suspicion for UTI in this population.

A narrative review on the application of artificial intelligence in renal ultrasound

Kidney disease is a serious public health problem and various kidney diseases could progress to end-stage renal disease. The many complications of end-stage renal disease. have a significant impact on the physical and mental health of patients. Ultrasound can be the test of choice for evaluating the kidney and perirenal tissue as it is real-time, available and non-radioactive. To overcome substantial interobserver variability in renal ultrasound interpretation, artificial intelligence (AI) has the potential to be a new method to help radiologists make clinical decisions. This review introduces the applications of AI in renal ultrasound, including automatic segmentation of the kidney, measurement of the renal volume, prediction of the kidney function, diagnosis of the kidney diseases. The advantages and disadvantages of the applications will also be presented clinicians to conduct research. Additionally, the challenges and future perspectives of AI are discussed.

The role of circumcision in preventing urinary tract infections in children with antenatal hydronephrosis: Systematic review and meta-analysis

INTRODUCTION

Circumcision has been reported to reduce the risk of urinary tract infections (UTIs) in boys with antenatal hydronephrosis (HN). Our aim was to compare the incidence of UTIs in circumcised vs. uncircumcised boys with antenatal HN by conducting a systematic review and meta-analysis.

STUDY DESIGN

A comprehensive search was performed until December 2022. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed measures included: UTIs, continuous antibiotic prophylaxis (CAP) use, renal outcomes, and circumcision complications. Odds ratios (OR) and mean difference with 95% confidence interval (CI) were extrapolated from available data. Random-effects meta-analysis were performed.

RESULTS

Twenty-three studies describing 9093 boys with antenatal HN were identified, including 4677 uncircumcised and 4416 circumcised boys. Overall effect estimates demonstrate that circumcised boys have significantly reduced odds of developing any UTI [OR 0.26, 95%CI 0.21, 0.32; p < 0.001]]. In addition, there a significantly reduced odds of developing UTI when circumcised and on CAP [OR 0.19, 95% CI 0.13, 0.30; p < 0.001]. When stratifying by etiology, circumcision reduced the odds of UTI in boys with isolated HN [OR 0.33, 95% CI 0.16, 0.68; p = 0.003], vesicoureteral reflux [OR 0.23, 95% CI 0.13, 0.42; P < 0.00001], or with posterior urethral valves [OR 0.29, 95% CI 0.13, 0.64; p = 0.002].

DISCUSSION

Circumcision reduces the incidence of UTIs in boys with antenatal HN. This review is limited by the varied definitions of UTIs and inconsistent reporting on HN etiology, renal outcomes, and circumcision complications.

CONCLUSIONS

Circumcision should be considered in boys with antenatal HN to prevent the risk of developing UTI. Further research is warranted to individualize the prophylactic role of circumcision for patients with HN.

Evaluation of pediatric hydronephrosis using deep learning quantification of fluid-to-kidney-area ratio by ultrasonography

PURPOSE

Hydronephrosis is the dilation of the pelvicalyceal system due to the urine flow obstruction in one or both kidneys. Conventionally, renal pelvis anterior-posterior diameter (APD) was used for quantifying hydronephrosis in medical images (e.g., ultrasound, CT, and functional MRI). Our study aimed to automatically detect and quantify the fluid and kidney areas on ultrasonography, using a deep learning approach.

METHODS

An attention-Unet was used to segment the kidney and the dilated pelvicalyceal system with fluid. The gold standard for diagnosing hydronephrosis was the APD > 1.0 cm. For semi-quantification, we proposed a fluid-to-kidney-area ratio measurement, i.e., [Formula: see text], as a deep learning-derived biomarker. Dice coefficient, confusion matrix, ROC curve, and Z-test were used to evaluate the model performance. Linear regression was applied to obtain the fluid-to-kidney-area ratio cutoff for detecting hydronephrosis.

RESULTS

For regional kidney segmentation, the Dice coefficients were 0.92 and 0.83 for the kidney and dilated pelvicalyceal system, respectively. The sensitivity and specificity of detecting dilated pelvicalyceal system were 0.99 and 0.83, respectively. The linear equation was fluid-to-kidney-area ratio = (0.213 ± 0.004) × APD (in cm) for 95% confidence interval on the slope with R² = 0.87. The fluid-to-kidney-area ratio cutoff for detecting hydronephrosis was 0.213. The sensitivity and specificity for detecting hydronephrosis were 0.90 and 0.80, respectively.

CONCLUSION

Our study confirmed the feasibility of deep learning characterization of the kidney and fluid, showing an automatic pediatric hydronephrosis detection.

Postnatal ultrasound follow-up in neonates with prenatal hydronephrosis

OBJECTIVES

Renal anomalies are the most common fetal abnormalities that occur during prenatal development, and are typically detected by observing hydronephrosis on fetal ultrasound imaging. Follow-up with post-natal ultrasound is important to detect clinically-important obstruction, because many of the pre-natal abnormalities resolve spontaneously. This study aimed to evaluate the postnatal hydronephrosis follow-up rate, and reasons for non follow-up in affected neonates.

METHODS

In this cross-sectional study all neonates born during a period of one year at Ayatollah Mousavi Hospital with hydronephrosis on fetal ultrasound imaging were recruited. All mothers were also given face-to-face information about fetal hydronephrosis and its postnatal outcomes, and follow-up with at least a postnatal ultrasound was recommended from the fourth day of their neonates' birth until the end of the fourth week. The neonates were subsequently observed for one month to determine the postnatal ultrasound follow-up rate and to reflect on diagnostic test results, reasons for failure to follow-up, as well as causes of hydronephrosis.

RESULTS

In this study, 71 cases (1.2%) out of 5,952 neonates had fetal hydronephrosis on prenatal ultrasound images. The postnatal ultrasound imaging showed kidney involvement in 18 neonates (25%), particularly in the left kidney (61.1%). Seven neonates had no follow-up at one month (10%). No significant relationship was found between lack of follow-up and the neonates' place of residence (p=0.42), maternal education (p=0.90), number of siblings (p=0.33), or gender (p=0.64).

CONCLUSIONS

Postnatal ultrasound follow-up rate in these neonates with a history of fetal hydronephrosis was incomplete even though parents had been provided with education and advice at their birth time. Accordingly, it is recommended to perform postnatal ultrasound once neonates are discharged from hospitals.

A Rare Case of Pyonephrosis in an Infant Induced by Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae

Pyonephrosis is a rare condition in both adult and pediatric population. Here, the author presents a rare case of pyonephrosis induced by extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a 12-month-old girl presenting with a picture of urosepsis. The patient presented with febrile urinary tract infection and was unresponsive to intravenous meropenem. Physical examination revealed huge, firm and irregular right renal swelling. Ultrasound and computed tomography imaging revealed severely hydronephrotic right kidney, and laboratory investigations showed elevated C-reactive protein level (22.9 mg/dl). Emergency percutaneous nephrostomy tube was inserted, pus was drained (20 ml) and intravenous vancomycin and amikacin were started. Her general condition improved, and urine culture was negative. Functional assessment with dimercaptosuccinic acid renal scan revealed that the split renal function was 5% on the right and 95% on the left side, and the bladder outline was smooth with no reflux in voiding cystourethrogram. A right nephrectomy was done a week later using the anterior subcostal approach. The postoperative course was smooth. Histopathological examination was diagnostic for xanthogranulomatous pyelonephritis. No adverse events were reported in the follow-up over 12 months. It can be concluded that a high degree of suspicion, rapid initiation of appropriate antibiotics and drainage of pus are crucial in the management of pyonephrosis.

Outcomes of urinary tract abnormalities diagnosed by the routine third trimester scan

OBJECTIVE

The aim of this study is to determine the incidence of congenital abnormalities of the kidneys and urinary tract (CAKUT) detected for the first time in an unselected population undergoing a routine third trimester scan between 30-34 week's gestation.

METHODS

This was a retrospective analysis of 8562 routine third trimester ultrasound scans during which the fetal anatomy was evaluated, and, any structural abnormalities detected, recorded onto a fetal database which was subsequently analysed for CAKUT. All postnatal records of antenatally diagnosed CAKUT were obtained and analysed for diagnosis and management.

RESULTS

There were 26 cases of urological abnormalities detected for the first time in the third trimester. The most frequent abnormality was unilateral renal pelvis dilatation (73%). Postnatal ultrasound confirmed abnormalities in 19 (73%) newborns, with two (8%) resolving antenatally and four (15%) postnatally. The overall incidence of new CAKUT detected by the third trimester scan was 0.22% (19/8562) with a male to female ratio of 1:1.6. Four patients required surgery, two received cystoscopic injection of Deflux with circumcision, one received cystoscopic valve ablation and one patient received a staged hypospadias repair.

CONCLUSION

Routine third trimester scanning is already performed in many countries with proposed benefits primarily directed towards the monitoring of fetal growth and late pregnancy malpresentation. For healthcare systems that still utilize two routine scans, debate is ongoing as to the value of introducing a routine third trimester scan. The ability to detect additional and potentially missed CAKUT is a further benefit, which in isolation is likely of too small an impact to merit implementation. However, the combination of fetal structural assessment, growth velocity monitoring and fetal presentation evaluation presents a strong case for inclusion in an antenatal screening program. The findings of this study highlight the importance of a detailed fetal structural evaluation at each antenatal ultrasound scan.

The role of antibiotic prophylaxis in mild to moderate isolated hydronephrosis detected in antenatal screening

Purpose

To determine whether continuous antibiotic prophylaxis (CAP) could prevent urinary tract infection (UTI) in mild to moderate antenatal isolated hydronephrosis (IH), characterized by hydronephrosis without ureter and bladder abnormalities, and anteroposterior renal pelvis diameter <16 mm and the Society for Fetal Urology grade <4, in neonatal renal ultrasound.

Materials and Methods

Eighty neonates aged 7 to 30 days, with antenatal hydronephrosis and mild to moderate IH on neonatal renal ultrasound, were recruited from August 2015 to December 2016. Neonates were randomly assigned to CAP until hydronephrosis resolution or aged 12 months (CAP group, n=40) or to watchful observation (control group, n=40). The primary outcome was UTI. The probability of UTI was compared between the randomized groups using the Kaplan-Meier method and the log-rank test.

Results

Nonadherence occurred in 6/40 parents in the CAP arm (15.0%). Thus, only 34 patients received CAP. UTI occurred in 5/34 patients in the CAP group (14.7%) and in 4/40 controls (10.0%). The probability of UTI was increased in the CAP group (hazard ratio, 1.38; 95% confidence interval, 0.37-5.16; p=0.63). UTI caused by cotrimoxazole resistant bacteria was four times higher in the CAP group than in controls (relative risk, 4.0; 95% confidence interval, 1.2-13.5; p=0.02). The trial was prematurely terminated due to the negative impact of CAP on bacterial sensitivity.

Conclusions

The benefits of CAP in infants with mild to moderate IH were inconclusive. CAP conferred a high risk of resistant bacterial organisms when UTI occurs.

Evaluation of Congenital Hydronephrosis with Static and Dynamic Magnetic Resonance Urography in Comparation to Dynamic Renal Scintigraphy

Introduction:

Congenital hydronephrosis (CH) is a condition with dilated renal pelvis with or without dilation of renal calyces.

Aim:

To examine the role of magnetic resonance urography in the detection of congenital hydronephrosis in comparison to dynamic renal scintigraphy (DRS).

Patients and methods:

Resarch included 58 (n=58) patients with diagnosis of congenital unilateral or bilateral dilatation of kidney duct system. Each patient had a one-time or multiple hospitalization at the Nephrology Department of the Pediatric Clinic, with performed: ultrasound which confirmed CH, voiding cystourethrography / voiding urosonography was confirmed based on which the vesicoureteral reflux (VUR) was established / excluded, dynamic renal scintigraphy and magnetic urography (analysis was made by CHOP-fMRU software) on the basis of which the uterine anatomy and the relative renal function were evaluated.

Results:

Male patients were represented in 40 cases (69%). The average age was 4.4 ± 4.3 years with the youngest patient at the age of 2 months, and the oldest was 17 years old. According to diagnostic entities, the most common diagnosis was ureteropelvic junction (UPJ) obstruction in over half of cases (30 or 51.7%), followed by subjects with ureterovesical junction (UVJ) obstruction (11 or 19%), VUR was recorded in 9 (15.5%) cases, and pyelon fissus in 7 (12.1%), and one case (1.7%) was recorded with bilateral megaureter. Comparison of the value of the renal function obtained with DRS and CHOP-fMRU methods shows that there were no statistically significant differences between two methods. In the case of right kidney, the mean DRS value was 53.4 ± 18.4% (range 13-100%), while CHOP-fMRU was 51.8 ± 22.4 (range 0-96.7%). In the case of left kidney, the average value according to the DRS method was 46.9 ± 18.9% (range 0-87%) and according to CHOP-fMRU 47.6 ± 21.5% (range 8.3-100%). The correlation coefficients of both right and left kidneys show a highly statistically significant correlation between these two methods.

Conclusion:

Magnetic resonance urography in the pediatric population in CH based on results should be an integral part of the management of these patients, especially in congenital obstructive uropathy, in complex and associated congenital anomalies, as it provides morphological and functional data on the state of the kidneys and urinary tract.

Antibiotic Prophylaxis Prescribing Patterns of Pediatric Urologists for Children with Vesicoureteral Reflux and other Congenital Anomalies of the Kidney and Urinary Tract

OBJECTIVE

To determine pediatric urologists' antibiotic prophylaxis prescribing practices for children with vesicoureteral reflux (VUR) and other congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

Web-based survey of pediatric urologists about their practice of antibiotic prophylaxis in children with CAKUT.

RESULTS

We had a response rate of 17.8% (n = 73). The majority of respondents always or often prescribe prophylactic antibiotics for grade IV or V VUR, while greater variability was seen for lower grades of VUR. 47.9% of respondents report that they often or always prescribe antibiotics for patients with grade 4 hydronephrosis, and most respondents report that they never or rarely prescribe antibiotics for grade 1 or 2 hydronephrosis. The majority of respondents never or rarely prescribe antibiotics for horseshoe or solitary kidney (88% and 86%, respectively), but frequently prescribed antibiotic for ureterocele. For ectopic ureter, almost half of respondents prescribe prophylactic antibiotics always or often, whereas only 18% prescribe antibiotics always or often for duplication anomalies. Only 11% reported prescribing antibiotics for prophylaxis always or often for children with myelomeningocele.

CONCLUSION

We report notable variability in antibiotic prescribing patterns for children with CAKUT. Given the lack of guidelines around the use of prophylaxis in the majority of these conditions, standardization of care may be warranted to decrease this variability.

Mild-to-moderate renal pelvis dilatation identified during pregnancy and hospital admissions in childhood: An electronic birth cohort study in Wales, UK

BACKGROUND

Chronic kidney disease (CKD) is a growing contributor to the global burden of noncommunicable diseases. Early diagnosis and treatment can reduce the severity of kidney damage and the need for dialysis or transplantation. It is not known whether mild-to-moderate renal pelvis dilatation (RPD) identified at 18-20 weeks gestation is an early indicator of renal pathology. The aim of this follow-up to the Welsh Study of Mothers and Babies was to assess the risk of hospital admission in children with mild-to-moderate antenatal RPD compared with children without this finding. We also examined how the natural history of the RPD (whether the dilatation persists in later pregnancy or postpartum) or its characteristics (unilateral versus bilateral) changed the risk of hospital admission.

METHODS/FINDINGS

This population-based cohort study included singleton babies born in Wales between January 1, 2009, and December 31, 2011 (n = 22,045). We linked ultrasound scan data to routinely available data on hospital admissions from the Patient Episode Database for Wales (PEDW). The outcome was a hospital admission for urinary tract causes (defined by an expert study steering group) in the first three years of life. We used Cox regression to model time to first hospital admission, according to whether there was evidence of RPD at the fetal anomaly scan (FAS) and/or evidence of dilatation in later investigations, adjusting for other predictors of admission. We used multiple imputation with chained equations to impute values for missing data. We included 21,239 children in the analysis. The risk of at least one hospital admission was seven times greater in those with RPD (n = 138) compared with those without (n = 21,101, conditional hazard ratio [cHR] 7.23, 95% confidence interval [CI] 4.31-12.15, p < 0.001). The risk of hospital admission was higher in children with RPD at the FAS and later dilatation (cHR 25.13, 95% CI 13.26-47.64, p < 0.001) and in children without RPD at the FAS who had later dilatation (cHR 62.06, 95% CI 41.10-93.71, p < 0.001) than in children without RPD (n = 21,057). Among children with RPD at the FAS but no dilatation in later pregnancy or postpartum, we did not find an association with hospital admissions (cHR 2.16, 95% CI 0.69-6.75, p = 0.185), except when the initial dilatation was bilateral (cHR 4.77, 95% CI 1.17-19.47, p = 0.029). Limitations of the study include small numbers in subgroups (meaning that these results should be interpreted with caution), that less severe outcomes (such as urinary tract infections [UTIs] managed in the community or in outpatients) could not be included in our analysis, and that obtaining records of radiological investigations later in pregnancy and postpartum was challenging. Our conclusions were consistent after conducting sensitivity analyses to account for some of these limitations.

CONCLUSIONS

In this large population-based study, children with RPD at the FAS had higher rates of hospital admissions when there was persistent dilatation in later pregnancy or postpartum. Our results can be used to improve counselling of parents and develop care pathways for antenatal screening programmes, including protocols for reporting and further investigation of RPD.

The association between continuous antibiotic prophylaxis and UTI from birth until initial postnatal imaging evaluation among newborns with antenatal hydronephrosis

INTRODUCTION

There is a lack of consensus regarding the use of continuous antibiotic prophylaxis (CAP) during the interval between birth and initial postnatal imaging in infants with a history of antenatal urinary tract dilation (AUTD).

OBJECTIVE

To determine the incidence of urinary tract infection (UTI), and the association between CAP use and UTI during the interval between birth and the first postnatal renal ultrasound (RUS) in infants with AUTD.

STUDY DESIGN

A single-institution, retrospective cohort study of newborns with a history of AUTD. Infants undergoing RUS within 3 months of birth for an indication of 'hydronephrosis' between 2012 and 2014 were identified. A random sample of 500 infants was selected; six were excluded for concomitant congenital anomalies. Baseline patient (sex, race, insurance) and clinical characteristics (circumcision status, UTD risk score, receipt of CAP, UTI prior to RUS, age at UTI, and age at RUS) were collected via retrospective chart review. Descriptive statistics were calculated. To adjust for receipt of CAP, propensity score adjusted univariate logistic regression for UTI based on CAP status was performed.

RESULTS

Among the 494 infants with AUTD, 157 (32%) received CAP. Infants with normal/low-risk UTD scores were less likely to receive CAP than those with medium/high-risk UTD (23% vs 77%; P < 0.001). There was no difference in CAP based on sex, insurance, or circumcision status (among 260/365 males with known circumcision status). Overall, seven infants (1.4%) developed UTI prior to imaging: six (1.8%) without CAP vs one (0.64%) with CAP (P = 0.44). The median age at UTI was 59 days (range 2-84); among those with UTI, initial imaging occurred significantly later (66 vs 28 days; P = 0.001). The propensity score adjusted odds of developing UTI with CAP (vs without) was 0.93 (95% CI 0.10-8.32; P = 0.95). The Summary Figure describes the infants with UTI.

CONCLUSION

The incidence of UTI prior to initial neonatal imaging in newborns with AUTD was low. Use of CAP was not associated with UTI incidence after adjusting for UTD severity. Routine use of CAP in newborns with AUTD prior to initial imaging may be of limited benefit in most patients.

Continuous Antibiotic Prophylaxis in Pediatric Urology

Continuous antibiotic prophylaxis (CAP) for urinary tract infection prevention in children with vesicoureteral reflux, hydronephrosis, and hydroureteronephrosis is reviewed. A more selective use of CAP is advocated based on a review of known individual risk factors in each of these conditions that subsequently helps identify the children most likely to benefit from CAP. Both short-term and potential long-term side effects of CAP are reviewed, including the impact of prophylactic antibiotics on bacterial resistance and the microbiome. Alternatives to continuous antibiotic prophylaxis including Vaccinium macrocarpon (Cranberry), probiotics, and vaccines are reviewed.

Neonatal Circumcision and Urinary Tract Infections in Infants With Hydronephrosis

BACKGROUND

Boys with urinary tract abnormalities may derive a greater benefit from newborn circumcision for prevention of urinary tract infection (UTI) than the general population. However, the effect of newborn circumcision on UTI is not well characterized across the etiological spectrum of hydronephrosis. We hypothesized that boys with an early diagnosis of hydronephrosis who undergo newborn circumcision will have reduced rates of UTI.

METHODS

The MarketScan data set, an employer-based claims database, was used to identify boys with hydronephrosis or hydronephrosis-related diagnoses within the first 30 days of life. The primary outcome was the rate of UTIs within the first year of life, comparing circumcised boys with uncircumcised boys and adjusting for region, insurance type, year of birth, and infant comorbidity.

RESULTS

A total of 5561 boys met inclusion criteria, including 2386 (42.9%) undergoing newborn circumcision and 3175 (57.1%) uncircumcised boys. On multivariate analysis, circumcision was associated with a decreased risk of UTI in both boys with hydronephrosis and healthy cohorts: odds ratio (OR) 0.36 (95% confidence interval [CI] 0.29-0.44) and OR 0.32 (95% CI 0.21-0.48), respectively. To prevent 1 UTI, 10 patients with hydronephrosis would have to undergo circumcision compared with 83 healthy boys. Among specific hydronephrosis diagnoses, circumcision was associated with a reduced risk of UTI for those with isolated hydronephrosis (OR 0.35 [95% CI 0.26-0.46]), vesicoureteral reflux (OR 0.35 [95% CI 0.23-0.54]), and ureteropelvic junction obstruction (OR 0.35 [95% CI 0.20-0.61]).

CONCLUSIONS

Newborn circumcision is associated with a significantly lower rate of UTI among infant boys with hydronephrosis.

Infants with prenatally diagnosed kidney anomalies have an increased risk of urinary tract infections

AIM

This study estimated the urinary tract infection (UTI) risk in a nationwide cohort of infants prenatally diagnosed with parenchymal kidney anomalies compared with a comparison cohort.

METHODS

A Danish population-based nationwide cohort of foetuses diagnosed with parenchymal kidney anomalies between 2007 and 2012 had previously been identified. These were compared with foetuses without kidney anomalies who were prenatally scanned the same year. Live born infants were followed from birth until the diagnosis of UTI, emigration, death or two years of age. Cumulative incidences of UTIs were computed. Mortality was estimated using the Kaplan-Meier method.

RESULTS

We identified 412 foetuses with parenchymal kidney anomalies out of 362 069 who underwent ultrasound scans and 277 were born alive. The overall risk of a UTI before the age of two years was 19%, and it was 14% among infants without prenatally diagnosed co-occurring urinary tract malformations. The corresponding risk in the 4074 controls was 1%. After two years, mortality was 2.2% in infants with prenatally diagnosed parenchymal kidney anomalies and 0.2% in the controls.

CONCLUSION

Infants prenatally diagnosed with parenchymal kidney anomalies had a substantially increased risk of UTI. Awareness of this increased risk may facilitate earlier diagnosis of UTIs in this population.

Incidence of urinary tract infections in infants with antenatally diagnosed hydronephrosis-A retrospective single center study

OBJECTIVE

To evaluate the incidence of urinary tract infections (UTIs) in infants with antenatal hydronephrosis (AHN).

MATERIALS AND METHODS

A cohort of AHN patients admitted to our institution between 2003 and 2013 were identified. Altogether 192 patients with nonrefluxing hydronephrosis (HN, n=135), nonrefluxing hydroureteronephrosis (HUN, n=21), or vesicoureteral reflux (VUR, n=36) were identified. Patients with complex anomalies or neonatal decompression of the urinary tract were excluded. Information about UTIs diagnosed among the AHN patients was collected and compared with data from 58 controls.

RESULTS

During the median follow-up time of 2.6 (0.3-11.2) years, 24 (13%) patients (15 (10%) males and 9 (19%) females) and 2 (3%) controls experienced at least one UTI (p=0.033). Eighteen (69%) UTIs were febrile. The males had the first UTI at significantly younger age than the females (0.3, 0.0-1.7years vs. 1.0, 0.4-4.8years, p=0.010). UTI was detected in 15 (63%) patients with grade 4-5 VUR, in 8 (6%) patients with HN, and in one (5%) patient with HUN (p-values <0.001, 0.726 and >0.999 against the controls). None of the patients with grade≤3 VUR had UTI. Fifty-eight percent of the patients with UTI were on antimicrobial prophylaxis. In five (12%) cases UTI appeared within one week after voiding cystourethrography (VCUG).

CONCLUSIONS

Infants with AHN and grade 4-5 VUR had the highest risk of UTI. UTIs tented to be more common in females than in males; however, males experienced UTI at younger age than females. VCUG caused UTI in 2.3% in our material.

LEVEL OF EVIDENCE

III.

Variable Resource Utilization in the Prenatal and Postnatal Management of Isolated Hydronephrosis

OBJECTIVE

To characterize contemporary resource utilization and medical outcomes for infants with antenatal hydronephrosis and their mothers from a national claims database. We hypothesize that management of isolated hydronephrosis (IHN) varies widely, with decreased imaging following the 2010 Society for Fetal Urology Consensus Statement.

MATERIALS AND METHODS

Using MarketScan claims from 2007 to 2013, we identified infants 0-12 months of age with hydronephrosis and linked mothers. Those with urologic diagnoses more specific than hydronephrosis, additional urologic comorbidities, or postnatal surgeries were excluded. Resource utilization including prenatal and postnatal imaging, laboratory studies, hospital admissions, and medical outcomes within the first year was captured. Demographics, maternal characteristics, utilization measures, and outcomes were compared across imaging intensity groups based on number of postnatal ultrasounds received using bivariate analysis.

RESULTS

Among 801,919 mother-child pairs, 8610 infants (1.1%) had hydronephrosis or a related diagnosis. A total of 5876 (68.2%) met inclusion criteria for IHN. Patients underwent a mean 5.3 ± 3.5 prenatal and 2.1 ± 1.3 postnatal ultrasounds before age 1. Imaging practices were unchanged following the Society for Fetal Urology consensus statement.

CONCLUSION

Antenatal hydronephrosis prevalence in an insured population is consistent with published ranges. Prenatal imaging in IHN is variable and potentially excessive. Future study into the efficacy of evidence-based pathways in reducing excess utilization is warranted.

Renal anomalies and lymphedema distichiasis syndrome. A rare association?

Lymphedema distichiasis syndrome (LDS) is a rare, autosomal dominant genetic condition, characterized by lower limb lymphedema and distichiasis. Other associated features that have been reported include varicose veins, cleft palate, congenital heart defects, and ptosis. We update a previously reported family with a pathogenic variant in FOXC2 (c.412-413insT) where five affected individuals from the youngest generation had congenital renal anomalies detected on prenatal ultrasound scan. These included four fetuses with hydronephrosis and one with bilateral renal agenesis. A further child with LDS had prominence of the left renal pelvis on postnatal renal ultrasound. We also describe a second family in whom the proband and his affected son had congenital renal anomalies; left ectopic kidney, right duplex kidney, and bilateral duplex collecting systems with partial duplex kidney with mild degree of malrotation, respectively. Foxc2 is expressed in the developing kidney and therefore congenital renal anomalies may well be associated, potentially as a low penetrance feature. We propose that all individuals diagnosed with LDS should have a baseline renal ultrasound scan at diagnosis. It would also be important to consider the possibility of renal anomalies during prenatal ultrasound of at risk pregnancies, and that the presence of hydronephrosis may be an indication that the baby is affected with LDS.

Continuous antibiotic prophylaxis in the setting of prenatal hydronephrosis and vesicoureteral reflux

Continuous antibiotic prophylaxis (CAP) has traditionally been offered for children with recurrent urinary tract infections (UTIs) or those at risk, including children diagnosed with prenatal hydronephrosis (HN) and vesicoureteral reflux (VUR). However, indications for antibiotic prophylaxis are controversial, data on who should benefit from this therapy is conflicting and, thus, guidelines are unable to provide conclusive recommendations. In the setting of prenatal HN, although randomized trials are currently underway, most evidence is derived from low- to moderate-quality observational studies. Although there is no benefit in those with low-grade HN, a systematic review of the available studies showed that high-grade HN patients on prophylaxis experienced fewer infections with an estimated number needed to treat of 7. On the other hand, there are eight randomized trials that have investigated the use of antibiotic prophylaxis in the setting of VUR. Although four of the studies have demonstrated some value of prophylaxis and the other four have not, meta-analysis has shown an overall benefit of antibiotic prophylaxis in preventing infections. The observed differences are likely due to different inclusion criteria and study heterogeneity. Although generalizing results of meta-analyses to all children is tempting, an individualized approach, by determining which patients best behave like those of the included studies, is recommended.

Antibiotic prophylaxis for prevention of urinary tract infections in prenatal hydronephrosis: An updated systematic review

INTRODUCTION

While continuous antibiotic prophylaxis (CAP) is currently recommended to prevent urinary tract infections (UTIs) in infants with prenatal hydronephrosis (HN), this recommendation is not evidence-based. The objective of this study was to systematically determine whether CAP reduces UTIs in the HN population.

METHODS

Applicable trials were identified through an electronic search of MEDLINE (1946-2015), EMBASE (1980-2016), CINAHL (1982-2016), and CENTRAL (1993-2016) and through a hand search of American Urological Association (AUA) (2012-2015) and European Society for Pediatric Urology (ESPU) (2012-2015) abstracts, as well as reference lists of included trials. The search strategy was not limited by language or year of publication. Eligible studies compared CAP to no CAP in patients with antenatal HN, <2 years of age, and reported development of UTI and HN grades. Two independent reviewers performed title and abstract screening, full-text review, and quality appraisal.

RESULTS

Of 1518 citations screened, 11 were included, contributing 3909 patients for final analysis. Of these, four (36%) were considered high-quality when assessed by the Newcastle Ottawa Scale. Meta-analysis of the non-randomized trials (n=10) provided similar pooled UTI rates, regardless of CAP use: 9.9% (95% confidence interval [CI] 8.4-11.4%) for CAP and 7.5% (95% CI 6.4-8.6%) for no CAP.

CONCLUSIONS

This systematic review and meta-analysis suggests there may be value in providing CAP to infants with high-grade HN; however, due to the very low-quality data from non-randomized studies, important clinical variables, such as circumcision status, were unable to be assessed.

Delayed upper tract drainage on voiding cystourethrogram may not be associated with increased risk of urinary tract infection in children with vesicoureteral reflux

INTRODUCTION

Urinary stasis in the setting of obstruction provides an opportunistic environment for bacterial multiplication and is a well-established risk factor for UTI. Vesicoureteral reflux (VUR) with delayed upper tract drainage (UTD) on VCUG has been reported to correlate with increased UTI risk. We sought to determine whether delayed UTD can be reliably classified, and whether it correlates with UTI incidence, VCUG, or endoscopic findings.

METHODS

Children undergoing endoscopic surgery for primary VUR (2009-2012) were identified. VUR grade, timing, and laterality were abstracted. Demographics, hydrodistention (HD) grade, reported febrile and culture-proven UTI were assessed. UTD on VCUG was graded on post-void images as 1 = partial/complete UTD or 2 = no/increased UTD. Inter-observer agreement was calculated. Patients were excluded for incomplete imaging or inability to void during VCUG.

RESULTS

The cohort included 128 patients (10M, 118F), mean age 4.1 ± 2.1 years. Mean age at diagnosis was 2.8 ± 2.8 years. Mean maximum VUR grade was 3 ± 0.9: 1 (7.8%), 2 (20.3%), 3 (43%), 4 (25.8%), 5 (3.1%). UTD occurred in 45 (35%), and no drainage in 83 (65%) patients. Agreement coefficient between graders was 0.596 (p < 0.0001). Cultures were available in 100 patients (70 positive). Patients experienced a mean of 2 ± 1.2 parent-reported fUTIs and 1.2 ± 1.2 culture-proven UTIs from birth to surgery. UTI rate did not differ by UTD status for parent or culture-proven UTI (Table). On multivariate analysis, no patient characteristic was a significant predictor of UTI based on drainage status. Children diagnosed with VUR before 1 year of age had a higher verified UTI rate (p < 0.001). However, drainage was not a significant predictor of UTI rate and when testing the interaction of drainage and age.

CONCLUSION

We sought to determine whether UTD was an accurate predictor of UTI risk to maximize available prognostic information from a single VCUG. Delayed UTD was not a predictor of infection in our patients, nor was it associated with previously described UTI risk factors, such as VUR timing or grade, and voiding dysfunction. Limitations included the retrospective nature of the study in patients undergoing endoscopic VUR treatment, and possible inaccurate UTI reports from parents and pediatricians. UTD can be reliably scored using a binary system with high inter-observer correlation. Our data call into question the previous finding that children with poor UTD are at increased risk of recurrent UTI. Delayed UTD is also not associated with higher HD, or VUR grade compared with those with more prompt UTD.

The outcome of antenatal ultrasound diagnosed anomalies of the kidney and urinary tract in a large Danish birth cohort

OBJECTIVE

Antenatal ultrasound diagnosed anomalies of the kidney and urinary tract (AUDAKUT) are reported in 0.3%-5% on prenatal ultrasound (US) and 0.3%-4.5% on postnatal US. The anterior-posterior diameter of the renal pelvis (APD) is an essential measurement. Series with low threshold values of APD prenatally and postnatally will include healthy infants. It is important to avoid follow-up of such infants.

INTERVENTIONS

In 2006, new Danish guidelines for AUDAKUT were introduced.

AIM OF STUDY

Investigations of incidences and type of AUDAKUT based on Danish guidelines, including long-term follow-up.

DESIGN

Cohort study.

SETTING

Copenhagen University Hospital Hvidovre and Copenhagen University Hospital Rigshospitalet, Denmark.

PATIENTS

Consecutive cases with AUDAKUT in the second and third trimesters, which were either terminated before 22 completed weeks of gestation or born in the 8-year period January 2006-December 2013. Patients were followed until June 2014.

RESULTS

50 193 live born children and 24 terminated fetuses (0.05%) were included. The prevalence of AUDAKUT was only 0.39% prenatally, 0.29% at first postnatal US and 0.22% at the end of follow-up, including terminated cases. The greater the prenatal and postnatal APD, the higher risk of febrile urinary tract infection (fUTI) and surgical intervention, and lower probability of resolution. 25% of the identified patients had fUTI and/or surgery.

CONCLUSIONS

We recommend threshold values of APD at least 10 mm in the third trimester and in general at least 12 mm at first postnatal US for intensive follow-up. In this largest to date unselected birth cohort of AUDAKUT, the incidences of clinically significant AUDAKUT were in the lowest range of those previously published.

Primary non-refluxive megaureter in children: single-center experience and follow-up of 212 patients

PURPOSE

Primary non-refluxing megaureter (pMU) is a multifaceted and challenging congenital pathology of the urinary tract. We report our 23-year experience with this anomaly in terms of presentation, diagnostic work-up and management.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 212 children diagnosed with pMU between 1986 and 2009 at our institution. Mean follow-up was 45.17 (0-192) months.

RESULTS

Of the total, 168 (79 %) children presented with upper urinary tract dilation on perinatal ultrasound screening. In 44 (21 %) patients, the diagnosis was made following diagnostic work-up of a urinary tract infection (UTI, 18 %) or flank pain (3 %). In total, 203 of 254 pMUs (79.9 %) were successfully treated conservatively during the 23-year observation period. Forty-eight children (23 %) underwent ureteric reimplantation. UTIs occurred in 91 of 212 children (43 %). Of these, 41 (45 %) occurred despite antibacterial infection prophylaxis. Within the past three decades, there has been a marked shift from surgical toward conservative therapy at our institution.

CONCLUSION

Neonatal renal ultrasound is the method of choice to timely identify children with pMU and, alongside dynamic renography, to monitor the clinical course. Nowadays, only a minor subset of children with asymptomatic course requires surgical correction. Antibacterial prophylaxis has the potential to reduce the risk of febrile UTIs. Prospective randomized studies are warranted to provide evidence of the beneficial effect of antibacterial prophylaxis.

From Research Question to Conducting a Randomized Controlled Trial on Continuous Antibiotic Prophylaxis in Prenatal Hydronephrosis: A Rational Stepwise Process

INTRODUCTION AND OBJECTIVES

Continuous antibiotic prophylaxis (CAP) use to prevent urinary tract infections (UTI) in infants with prenatal hydronephrosis (HN) remains controversial. Lack of consensus guidelines and diverse practice patterns for postnatal management of HN highlight the dire need for higher level of evidence studies. Herein, we aim to describe the steps from developing a well-defined research question to execute a multicentered randomized controlled trial (RCT) to address the issue of CAP use in patients with prenatal HN.

MATERIALS AND METHODS

The steps involved were (1) choosing the proper research question, (2) survey of practice patterns and establishing clinical equipoise, (3) systematic review of the literature, (4) reviewing own practice, (5) longitudinal prospective study, (6) pilot study, (7) cost-utility analysis, and (8) definitive RCT (clinical trials registry number: NCT01140516). An update of our previous systematic review was conducted using two electronic databases and gray literature from 2010 to 2015. Eligibility criteria included studies of children <2 years old with postnatally confirmed prenatal HN, receiving CAP or not, and reporting on development of UTIs, capturing information on voiding cystourethrogram result and HN grade. Full-text screening was conducted by two independent reviewers. UTI rates in patients with high-grade HN were compared across different study designs. Finally, blinded comparative analysis of UTI rates between placebo and treatment groups was carried out using chi-square test.

RESULTS

UTI rates in patients with high-grade HN by their respective study design were: 25% for systematic review, 20% for retrospective study, 21% for prospective and pilot studies, and 13% for the definitive RCT thus far. Regardless of the type of study design, patients with hydroureteronephrosis had significantly higher (threefold to sixfold) UTI rates than those with isolated HN. Our updated systematic review yielded 486 citations, of which 9 (n = 1987 infants) observational studies met eligibility criteria.

CONCLUSION

UTI rates in patients with high-grade HN dropped from 25% in observational studies to 13% in our RCT. This decline in UTI rate demonstrates that study designs lacking strategies to minimize bias are more prone to overestimate treatment effects. These findings highlight the importance of conducting methodologically sound RCTs to answer clinically meaningful questions, such as the one presented here.

Economic analysis of continuous antibiotic prophylaxis for prevention of urinary tract infections in infants with high-grade hydronephrosis

BACKGROUND

For infants with hydronephrosis, continuous antibiotic prophylaxis (CAP) may reduce urinary tract infections (UTIs); however, its value remains controversial. Recent studies have suggested that neonates with severe obstructive hydronephrosis are at an increased risk of UTIs, and support the use of CAP. Other studies have demonstrated the negligible risk for UTIs in the setting of suspected ureteropelvic junction obstruction and have highlighted the limited role of CAP in hydronephrosis. Furthermore, economic studies in this patient population have been sparse.

OBJECTIVE

This study aimed to evaluate whether the use of CAP is an efficient expenditure for preventing UTIs in children with high-grade hydronephrosis within the first 2 years of life.

STUDY DESIGN

A decision model was used to estimate expected costs, clinical outcomes and quality-adjusted life years (QALYs) of CAP versus no CAP (Fig. 1). Cost data were collected from provincial databases and converted to 2013 Canadian dollars (CAD). Estimates of risks and health utility values were extracted from published literature. The analysis was performed over a time horizon of 2 years. One-way and probabilistic sensitivity analyses were carried out to assess uncertainty and robustness.

RESULTS

Overall, CAP use was less costly and provided a minimal increase in health utility when compared to no CAP (Table). The mean cost over two years for CAP and no CAP was CAD$1571.19 and CAD$1956.44, respectively. The use of CAP reduced outpatient-managed UTIs by 0.21 infections and UTIs requiring hospitalization by 0.04 infections over 2 years. Cost-utility analysis revealed an increase of 0.0001 QALYs/year when using CAP. The CAP arm exhibited strong dominance over no CAP in all sensitivity analyses and across all willingness-to-pay thresholds.

DISCUSSION

The use of CAP exhibited strong dominance in the economic evaluation, despite a small gain of 0.0001 QALYs/year. Whether this slight gain is clinically significant remains to be determined. However, small QALY gains have been reported in other pediatric economic evaluations. Strengths of this study included the use of data from a recent systematic review and meta-analysis, in addition to a comprehensive probabilistic sensitivity analysis. Limitations of this study included the use of estimates for UTI probabilities in the second year of life and health utility values, given that they were lacking in the literature. Spontaneous resolution of hydronephrosis and surgical management were also not implemented in this model.

CONCLUSION

To prevent UTIs within the first 2 years of life in infants with high-grade hydronephrosis, this probabilistic model has shown that CAP use is a prudent expenditure of healthcare resources when compared to no CAP.

Risk factors for febrile urinary tract infection in children with prenatal hydronephrosis: a prospective study

PURPOSE

We prospectively investigated the impact of risk factors for febrile urinary tract infection in infants with postnatally confirmed prenatal hydronephrosis.

MATERIALS AND METHODS

Patients seen for prenatal hydronephrosis from 2010 to 2013 were prospectively followed. Those with ectopic ureters and ureteroceles, posterior urethral valves and neuropathic bladders were excluded. The primary outcome was febrile catheter specimen urinary tract infection. We performed univariate analysis of 7 a priori risk factors, including age, hydronephrosis grade (low-I or II vs high-III or IV), type (isolated hydronephrosis vs hydroureteronephrosis), continuous antibiotic prophylaxis, vesicoureteral reflux grade, gender and circumcision status. Time to febrile urinary tract infection curves analyzed by Cox proportional regression were generated to adjust for confounders.

RESULTS

We collected data on 334 patients, of whom 78% were male. A febrile urinary tract infection developed in 65 patients (19%) at a median of 4 months (range 1 to 31). High grade hydronephrosis was present in 192 infants (57%). Continuous antibiotic prophylaxis was prescribed in 96 cases (29%). Of patients on continuous antibiotic prophylaxis 69% had high grade hydronephrosis. Vesicoureteral reflux was identified in 57 of 238 patients in whom voiding cystourethrogram was done. Reflux was grade I to III in 14 cases and grade IV or V in 43. Two-thirds of the patients with reflux were on continuous antibiotic prophylaxis. Circumcision was performed in 95 males (36%). Cox proportional regression identified female gender (HR 3.3, p = 0.02), uncircumcised males (HR 3.2, p = 0.02), hydroureteronephrosis (HR 10.9, p <0.01), vesicoureteral reflux (HR 20.8, p <0.01) and lack of continuous antibiotic prophylaxis (HR 5.2, p <0.01) as risk factors for febrile urinary tract infection. Subgroup analysis excluding vesicoureteral reflux showed that high grade prenatal hydronephrosis was also a significant risk factor (HR 3.0, p = 0.04).

CONCLUSIONS

After patients with vesicoureteral reflux were excluded from the study, females and uncircumcised males with high grade hydroureteronephrosis had significantly higher febrile urinary tract infection rates. Therefore, those patients may benefit from continuous antibiotic prophylaxis.

Postnatal management of antenatally detected hydronephrosis

With the increasing use of ultrasonography, congenital anomalies are often picked in utero. Antenatally detected hydronephrosis is amongst the most commonly detected abnormality. The management of this condition has raised considerable debate amongst clinicians dealing with it. This article is written with an idea to provide comprehensive information regarding the postnatal management of antenatally detected hydronephrosis. A detailed review of the current literature on this topic is provided. Also, guidelines have been given to facilitate the management of this condition.

Severity of birth defects after propylthiouracil exposure in early pregnancy

BACKGROUND

Propylthiouracil (PTU) used in the treatment of maternal hyperthyroidism in early pregnancy may be associated with a higher prevalence of birth defects in the face and neck region and in the urinary system but the severity of these complications remains to be elucidated.

METHODS

Review of hospital-registered cases of birth defects in the face and neck region and in the urinary system after PTU exposure in early pregnancy. We obtained information on maternal redeemed prescription of PTU and child diagnosis of birth defect from nationwide registers for all children born in Denmark between 1996 and 2008 (n=817,093). The children were followed until December 31, 2010 (median age, 8.3 years) and the Cox proportional hazards model was used to estimate adjusted hazard ratio (HR) with 95% confidence interval (CI) for having a birth defect after PTU exposure versus nonexposed children (n=811,730).

RESULTS

Fourteen cases of birth defects were identified in the face and neck region and in the urinary system after PTU exposure in early pregnancy; 11 children were exposed to PTU only (n=564), whereas 3 children were born to mothers who switched from methimazole (MMI)/carbimazole (CMZ) to PTU in early pregnancy (n=159). Among children exposed to PTU only, the adjusted HR for having a birth defect in the face and neck region was 4.92 (95% CI 2.04-11.86) and in the urinary system 2.73 (1.22-6.07). Looking into details of the 14 cases, 7 children were diagnosed with a birth defect in the face and neck region (preauricular and branchial sinus/fistula/cyst) and 7 children had a birth defect in the urinary system (single cyst of kidney and hydronephrosis). Surgical treatment was registered in 6 of the cases with a birth defect in the face and neck region and 3 of the cases with a birth defect in the urinary system. Two of the children with a birth defect in the urinary system also had other birth defects (genital organs).

CONCLUSIONS

We report details on possible PTU-associated birth defects. They tend to be less severe than the defects observed after MMI/CMZ exposure. Yet, the majority of affected children had to undergo surgery.

Hydronephrosis: prenatal and postnatal evaluation and management

Antenatal hydronephrosis (ANH) is one of the most frequently detected abnormalities found on routine prenatal ultrasounds, affecting 1% to 4.5% of all pregnancies. Despite its prevalence, there continues to be uncertainty regarding the clinical impact after birth. Prognosis depends on the severity of the dilation. Expectant prenatal management is the rule with fetal intervention rarely needed in a few select cases. Ureteropelvic junction obstruction and vesicoureteral reflux are the most common postnatal diagnoses. A renal and bladder ultrasound is essential in the follow-up of patients with ANH and helps dictate further investigation with voiding cystourethrography and/or diuretic renography.

Continuous antibiotic prophylaxis reduces the risk of febrile UTI in children with asymptomatic antenatal hydronephrosis with either ureteral dilation, high-grade vesicoureteral reflux, or ureterovesical junction obstruction

BACKGROUND

The efficacy and utility of continuous antibiotic prophylaxis (CAP) in children with congenital antenatal hydronephrosis (ANH) is uncertain. The literature has both supportive and contradictory evidence. The growing trend not to place children with ANH on CAP has created varied clinical practice based on anecdotal individual case characteristics. Our goal was to compare individual infant characteristics between those children who were maintained on CAP to those that were not to try to determine predisposing risk factors to febrile.

METHODS

All electronic medical records (EMRs) of children referred to our institution for congenital ANH over a period from 2001 to 2011 were examined. We excluded those referred for urinary tract infection (UTI) who had a history of congenital ANH. We also excluded those with incomplete records, or follow-up less than 2 years. Children were divided into two groups: those maintained on CAP (YCAP) and those not maintained on CAP (NCAP). Our primary endpoint was febrile UTI. Follow-up was at least 24 months. Demographic, perinatal and postnatal clinical data were recorded. Statistical analysis was performed using STATA Version 11.1.

RESULTS

Of the 405 children fitting inclusion criteria, 278 (68.6%) children were maintained on CAP and 127 (31.4%) were not on CAP. The incidence of prematurity, oligohydramnios, perinatal respiratory complications, use of perinatal antibiotics, circumcision status, renal anomalies, associated medical diagnoses, and low birth weight did not differ between the two groups. Overall the incidence of febrile UTI during the follow-up period was 22.2%. The incidence of febrile UTI between the YCAP and NCAP groups was significant (YCAP = 7.9% and NCAP 18.7%, p = 0.021). Multivariate logistic regression using CAP as the dichotomous dependent variable revealed that ureteral dilation, high-grade vesicoureteral reflux (VUR), and ureterovesical junction (UVJ) obstruction were independent risk factors for febrile UTI. More specifically, children with ureteral dilation >11 mm NOT maintained on CAP had a 5.54 (OR = 5.54; CI = 3.15-7.42, p = 0.001) fold increased risk of febrile UTI compared to those maintained on CAP.

CONCLUSIONS

The presence of ureteral dilation, high grade VUR, and UVJ obstruction were independent risk factors for development of UTI in children with congenital ANH. Therefore CAP may have a significant role in reducing the risk of febrile UTI in children with ANH with those identifiable risk factors, but otherwise seems unnecessary.

Environmental factors for the development of fetal urinary malformations

BACKGROUND

The development of the kidneys and other organs of the urinary tract also follow the natural rule of gene-environment-lifestyle interaction. Both intrinsic and extrinsic factors may be associated with the etiology of various kinds of urinary malformations. The environmental factors belong to extrinsic factors, which have attracted increasing attention from researchers.

METHODS

Publications about urinary malformations were searched from databases such as PubMed, Elsevier, Chemical Abstract, Excerpta Medica, Chinese Hospital Knowledge Database and Wanfang Database.

RESULTS

Urinary malformation is associated with low birth weight, maternal diseases, placental insufficiency, maternal drug exposure, and maternal exposure to environmental pesticides. Living environment and socioeconomic factors may also influence the incidence of urinary malformation.

CONCLUSION

It is important to understand the association of environmental factors with the development of the renal system and urinary malformation in order to decrease the incidence of urinary malformations.

Primary neonatal MRSA pyonephrosis

Pyonephrosis is uncommon in adult and paediatric population and very rare in neonates. Neonatal candidal and staphylococcal pyonephrosis has been reported earlier, and this is the first reported case of MRSA pyonephrosis. A case of potentially lethal fulminating primary MRSA pyonephrosis with septic shock in a neonate in whom investigations showed refluxing and obstructing left megaureter requiring successful surgical correction has been reported.

Antenatally diagnosed hydronephrosis: current postnatal management

The issue of antenatal hydronephrosis has become a routine component for the care of a pregnant woman despite limited evidence of a clinical benefit. The genitourinary tract represents the most commonly detected organ system with identified abnormalities, with antenatal hydronephrosis (ANH), being the most notable and common finding. ANH represents a spectrum, with most cases being a trivial and inconsequential finding on maternal fetal ultrasound. However, there is a correlation with increased grades of ANH being associated with increased severity of urinary tract pathology. Most patients can be managed expectantly with appropriate evaluation commenced postnatally based on severity of ANH and proper parental counseling and education. The purpose of this review was to assess current literature and guidelines pertaining to ANH and incorporate our practical interpretations of their significance.

Revised guidelines on management of antenatal hydronephrosis

Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.

Current management of antenatal hydronephrosis

The strategy for the management of children with urinary tract anomalies has changed considerably as a result of the development of ultrasound equipment and techniques that allow for detailed fetal evaluation. Hydronephrosis is the most common urogenital anomaly detected, suggesting that an obstructive process may be potentially present. The goal of postnatal management is to identify and treat those patients whose renal function is at risk, while leaving alone the high percentage of patients who are at no risk of renal damage. This management involves a spectrum of radiological, medical, and surgical interventions for diagnosis, surveillance, and treatment. In this article, we review our current understanding of the natural history of antenatal hydronephrosis and its management.

[Primary megaureter]

A primary megaureter is an anomaly with a prevesical or overall dilated ureter of more than 6 mm in diameter. It is important to distinguish between cases of primary non-refluxing and primary obstructive-refluxing megaureters, as the treatment of both is completely different. The basic diagnostic work-up includes ultrasonography and voiding cystourethrography. Diuretic renography is used to detect split renal function and the degree of upper urinary tract obstruction. In most cases of primary non-refluxing megaureter surgical treatment is unnecessary due to the high remission rate, whereas obstructive refluxing megaureters commonly only need to be corrected. Antibiotic prophylaxis may be indicated in infants with a primary obstructive megaureter during the first 6 months of life due to a higher risk of complications due to pyelonephritis especially in this age group.

Evaluation and management of urinary tract infections in the neonate

PURPOSE OF REVIEW

The prevalence of urinary tract infections (UTIs) among full-term neonates has been reported to be up to 1.1%, increasing up to 7% among those with fever. UTI in neonates may be the first indicator of underlying abnormalities of kidneys and the urinary tract.

RECENT FINDINGS

Early recognition and therapy of UTI and detection of risk factors offer chances for applying strategies to avoid renal damage and recurrences. However, established diagnostic strategies and prophylactic concepts today are under debate. Currently, the main focus has been on renal changes as indicators for underlying risk factors like vesicoureteral reflux, attaching much importance to dimercaptosuccinyl acid scans. Serum and urine markers will probably allow more restrictive diagnostic imaging. Prenatal and postnatal ultrasound screenings provide additional opportunities for prophylactic measures.

SUMMARY

Main objectives in the management of neonatal UTIs are the prevention of acute infection-related complications and renal damage. Neonates and very young infants with suspicious pyelonephritis should obligatorily be treated with a combination of parenterally administered antibiotics. As far as possible, diagnostic imaging should be risk-oriented and restricted to noninvasive, nonstressful procedures. The strategies of antibacterial prophylaxis for the prevention of recurrent UTIs are changing. In infants at risk, its benefits have not yet been proven by evident data.

Clinical course of 822 children with prenatally detected nephrouropathies

BACKGROUND AND OBJECTIVES

With the advent of fetal screening ultrasonography, the detection of congenital anomalies of the kidney and urinary tract (CAKUT) in utero has permitted early management of these conditions. This study aims to describe the clinical course of a large cohort of patients with prenatally detected nephrouropathies.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this retrospective cohort study, 822 patients were prenatally diagnosed with CAKUT and systematically followed up at a tertiary Renal Unit for a median time of 43 months. Variables included in the analysis were sex, laterality, fetal ultrasonography (isolated versus associated hydronephrosis), and presence/absence of nephrouropathies. The events of interest were urinary tract infection, surgical interventions, hypertension, CKD, and death. Survival analyses were performed to evaluate time until occurrence of the events of interest.

RESULTS

Urinary tract infection occurred in 245 (29.8%) children, with higher risk in females (hazard ratio=1.30, 95% confidence interval=1.02-1.70, P=0.05); 22 patients (2.7%) had hypertension, and 49 (6%) patients developed CKD. The risk of CKD was greater in patients with associated hydronephrosis (hazard ratio=5.20, 95% confidence interval=2.90-9.30, P<0.001). Twelve patients (1.5%) died during follow-up. Death was significantly associated with being born during the first period of the study (hazard ratio=6.00, 95% confidence interval=1.60-22.50, P<0.001), associated hydronephrosis (hazard ratio=9.30, 95% confidence interval=2.90-29.30, P<0.001), and CKD (hazard ratio=170.00, 95% confidence interval=41.00-228.00, P<0.001).

CONCLUSIONS

In our series, the clinical course of prenatally detected CAKUT was heterogeneous, and those infants with associated hydronephrosis at baseline were identified as a high-risk subgroup.

The Society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis

The evaluation and management of fetuses/children with antenatal hydronephrosis (ANH) poses a significant dilemma for the practitioner. Which patients require evaluation, intervention or observation? Though the literature is quite extensive, it is plagued with bias and conflicting data, creating much confusion as to the optimal care of patients with ANH. In this article, we summarized the literature and proposed recommendations for the evaluation and management of ANH.