Early risk factors for neonatal mortality in CAKUT: analysis of 524 affected newborns

Practical Approach to Congenital Anomalies of the Kidneys: Focus on Anomalies With Insufficient or Abnormal Nephron Development: Renal Dysplasia, Renal Hypoplasia, and Renal Tubular Dysgenesis

Congenital anomalies of the kidney and urinary tract (CAKUT) accounts for up to 30% of antenatal congenital anomalies and is the main cause of kidney failure in children worldwide. This review focuses on practical approaches to CAKUT, particularly those with insufficient or abnormal nephron development, such as renal dysplasia, renal hypoplasia, and renal tubular dysgenesis. The review provides insights into the histological features, pathogenesis, mechanisms, etiologies, antenatal and postnatal presentation, management, and prognosis of these anomalies. Differential diagnoses are discussed as several syndromes may include CAKUT as a phenotypic component and renal dysplasia may occur in some ciliopathies, tumor predisposition syndromes, and inborn errors of metabolism. Diagnosis and genetic counseling for CAKUT are challenging, due to the extensive variability in presentation, genetic and phenotypic heterogeneity, and difficulties to assess postnatal lung and renal function on prenatal imaging. The review highlights the importance of perinatal autopsy and pathological findings in surgical specimens to establish the diagnosis and prognosis of CAKUT. The indications and the type of genetic testing are discussed. The aim is to provide essential insights into the practical approaches, diagnostic processes, and genetic considerations offering valuable guidance for pediatric and perinatal pathologists.

Nadir Creatinine in Congenital Anomalies of the Kidney and Urinary Tract (CAKUT): A Single-Center Experience

BACKGROUND/OBJECTIVES

Congenital anomalies of the kidney and urinary tract (CAKUT) are the main cause of chronic kidney disease (CKD) requiring renal replacement therapy (RRT) in children, being the leading cause (50-70%) of end-stage renal disease (ESRD) in children and young adults. Our study aimed to assess the natural evolution of various antenatally diagnosed renal malformations and to identify potential prognostic factors to guide the therapeutic management of patients with CAKUT.

METHODS

We conducted a retrospective study on 205 children with CAKUT. For each patient, analyzing their medical records, we established the nadir value of serum creatinine, defined as the lowest creatinine level during the first year of life. We assessed the value of nadir creatinine as a prognostic marker in patients with CAKUT, and using an ROC curve, we also determined a threshold value of nadir creatinine that predicted progression to ESRD.

RESULTS

The male-to-female ratio was 2.8 to 1. The mean gestational age at detection was 29.85 weeks (±6.71). A total of 36 patients (17.6%) had impaired renal function, of which 8 (3.9% of the total) progressed to ESRD. The mean nadir creatinine in patients with ESRD was 1.39 mg/dL. A nadir creatinine cut-off of 0.98 mg/dL had high sensitivity and specificity in identifying patients with progression to ESRD, with an AUC of 0.95 and a 95% confidence interval between 0.86 and 1.05 mg/dL.

CONCLUSIONS

Our results support the value of nadir creatinine in predicting progression to ESRD, consistent with previously published data.

Novel CHRNA3 variants identified in a patient with bladder dysfunction, dysautonomia, and gastrointestinal dysmotility

Congenital anomalies of the kidney and urinary tract (CAKUT) are estimated to be responsible for 20%-50% of congenital anomalies and are also a leading etiology of early-onset renal disease. Primary CAKUT are caused by genetic factors that impair proper in-utero genitourinary tract development and secondary CAKUT result from the influence of environmental factors. The CHRNA3 gene, which encodes the Alpha-3 subunit of the nicotinic acetylcholine receptor, is hypothesized to be associated with Megacystis-microcolon-intestinal hyperperistalsis syndrome. More recently, pathogenic variants in CHRNA3 have been identified in individuals with CAKUT as well as individuals with panautonomic failure. Here we present a patient with neurogenic bladder, vesicoureteral reflux, mydriasis, and gastrointestinal dysmotility found to have novel compound heterozygous variants in CHRNA3. These findings support the consideration of CHRNA3 disruption in the differential for CAKUT with dysautonomia and gastrointestinal dysmotility.

Validation of ICD-9-CM codes for major genitourinary birth defects in Military Health System administrative data, 2006-2014

BACKGROUND

The Department of Defense Birth and Infant Health Research program is dedicated to birth defects research and surveillance among military families. Here, we assess and refine the validity of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for selected genitourinary birth defects in the Military Health System (MHS). We additionally outline methods for the calculation of positive predictive value (PPV) and negative predictive value (NPV), sensitivity, and specificity using a stratified sampling design.

METHODS

Among military infants born from 2006 through 2014, a random sample of ICD-9-CM screen-positive cases (for six genitourinary birth defects) and screen-negative cases were selected for chart review. PPV, NPV, sensitivity, and specificity were calculated for individual defects and any included defect (i.e., overall); measures were weighted by the inverse probability of being sampled.

RESULTS

Of 461,557 infants, 686 were sampled for chart review. Bladder exstrophy was accurately reported (PPV: >90%), while the accuracy of renal dysplasia, renal agenesis/hypoplasia, and hypospadias was moderate (PPVs: 66%-68%) and congenital hydronephrosis was low (PPV: 20%). Specificity and NPVs always exceeded 98%. The overall PPV was 50%; however, excluding congenital hydronephrosis screen-positive cases and requiring at least two inpatient or outpatient diagnostic codes resulted in a PPV of 85%.

CONCLUSIONS

The validity of major genitourinary birth defect codes varied in MHS administrative data. The accuracy of an overall defect measure improved by omitting congenital hydronephrosis and requiring at least two diagnostic codes. Although PPV is generally useful for research, additional calculation of NPV, sensitivity, and specificity better informs the identification of appropriate selection criteria across surveillance and research settings.

Associations between maternal chronic diseases and congenital anomalies of the kidney and urinary tract in offspring: a population-based cohort study

Background

The relationship between maternal chronic diseases and congenital anomalies of the kidneys and urinary tract (CAKUT) in offspring still needs elucidation. This study aimed to comprehensively evaluate the associations between maternal chronic disease and CAKUT in their offspring.

Methods

Data of mothers and children were extracted from the Taiwan Maternal and Child Health Database and National Health Insurance Research Database. The concept of developmental origins of health and disease (DOHaD) was used to select maternal chronic diseases.

Results

The study cohort included 1 196 175 mothers and 1 628 706 offspring. Analysis showed that maternal chronic diseases, especially type 1 diabetes, type 2 diabetes, gestational diabetes, connective tissue disorders and CAKUT were highly associated with CAKUT in the offspring. Higher maternal age, abnormal birthweight (>3500 g or <2500 g), gestational age <36 weeks and birth order <2 were all associated with a higher risk of CAKUT. Maternal chronic hypertension and taking angiotensin-related drugs increased the odds ratios of obstructive kidney disease in the offspring. Offspring tended to have the same type of CAKUT as their mothers.

Conclusion

Maternal chronic diseases, older maternal age and abnormal birthweight are risk factors for CAKUT. Also, a percentage of patients with CAKUT were not full-term newborns. Results support prenatal counselling and health management of pregnant women with chronic diseases and extra care for infants with a high risk of anomalies. It is strongly recommended that prevention of CAKUT in offspring should start with care of the mothers' prenatal chronic diseases.

Observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT): assessment and evaluation as predictive factor for acute postnatal outcome-a single center study

Introduction

To assess the observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT) and to explore its value as a potential predictive factor for postnatal outcome.

Methods

A retrospective single-center study was conducted on pregnancies complicated by CAKUT between 2007 and 2018. The lung-to-head ratio (LHR) was calculated for each fetus by two independent observers. Correlations between O/E LHR and various perinatal outcome factors were assessed with Spearman's rank correlation. Furthermore, nominal logistic regression was performed to assess O/E LHR as predictive factor for respiratory distress in newborn.

Results

Of 64 pregnancies complicated by CAKUT, 23 were terminated. In the 41 cases of continuation of pregnancy, newborn presenting respiratory distress with need for respiratory support in the delivery room showed earlier gestational age at onset of amniotic fluid abnormalities and at birth. Although median O/E LHR and median single deepest pocket (SDP) of amniotic fluid were significantly smaller in newborn that did develop respiratory distress with need of respiratory support in the delivery room, neither O/E LHR nor SDP were accurate predictors for the development of respiratory distress.

Conclusions

Our data show that O/E LHR alone cannot serve as a predictive marker for fetal outcome in pregnancies complicated by CAKUT, though it might still be a helpful parameter together with detailed renal ultrasound evaluation, onset of amniotic fluid abnormality and SDP, particularly in its extreme values.

Kidney transplant access for children and young adults with congenital anomalies of the kidney and urinary tract

PURPOSE

Although congenital anomalies of the kidney and urinary tract (CAKUT) are among the leading causes of end-stage kidney disease (ESKD) in children and young adults, kidney transplantation access for this population has not been well studied in the US. We compared transplantation access in the US based on whether the etiology of kidney disease was secondary to CAKUT, and additionally by CAKUT subgroups (anatomic vs. inherited causes of CAKUT).

METHODS

Using the United States Renal Data System, we conducted a retrospective cohort study of 80,531 children and young adults who started dialysis between 1995 and 2015. We used adjusted Cox models to examine the association between etiology of kidney disease (CAKUT vs. non-CAKUT, anatomic vs. inherited) and receipt of kidney transplantation, and secondarily, receipt of a living vs. deceased donor kidney transplant.

RESULTS

Overall, we found an increased likelihood of kidney transplantation access for participants with CAKUT compared to those without CAKUT (HR 1.23; 95% CI 1.20-1.27). Among the subset of individuals with CAKUT as the attributed cause of ESKD, we found a lower likelihood of kidney transplantation in those with anatomic causes of CAKUT compared to those with inherited causes of CAKUT (adjusted HR 0.85; 0.81-0.90).

CONCLUSION

There are notable disparities in kidney transplantation rates among CAKUT subgroups. Those with anatomic causes of CAKUT started on dialysis have significantly reduced access to kidney transplantations compared to individuals with inherited causes of CAKUT who were initiated on dialysis. Further studies are needed to understand barriers to transplantation access in this population.

Fetal Nephrology: A Quaternary Care Center Experience

Key Points

Specialized fetal centers see a highly complex subset of patients with CAKUT with a predominance of complex or syndromic disease. The mortality rate for fetuses with complex developmental anomalies and CAKUTs or bilateral CAKUTs is high. Prenatal genetic testing was highly variable with limited diagnostic utility while focused postnatal genetic testing had much higher yield.

Background

Congenital anomalies of the kidney and urinary tract (CAKUTs) represent 15%–20% of prenatally diagnosed abnormalities. Maternal characteristics, the frequency of various forms of kidney disease including CAKUT referred for prenatal nephrology consultation, and their perinatal outcomes are less well defined.

Methods

A retrospective chart review was performed of fetal CAKUT and other forms of kidney disease referred for prenatal nephrology consults at Texas Children's Hospital Fetal Center from January 1, 2012, to December 31, 2018.

Results

Two hundred seventeen prenatal nephrology consultations were performed during the study period, representing 4.7% of total Fetal Center referrals at a mean estimated gestational age of 25.2±5.7 weeks. Maternal characteristics were as follows: The mean age was 29.3±5.6 years; 14% had advanced maternal age; 10% had a family history of CAKUT or ESKD; 5% had diabetes mellitus; and 5% of pregnancies were in vitro fertilization-assisted. Fetal characteristics were as follows: 62.7% of fetuses were male and 16% had CAKUT associated with multiple congenital anomalies. The most common prenatal diagnoses were lower urinary tract obstruction in 71 (32.7%), unilateral renal agenesis or multicystic dysplastic kidney (MCDK) in 52 (24.9%), bilateral agenesis or MCDK in 22 (10.1%), and bilateral cystic kidney disease in 19 (8.8%). Seventy-six percent of patients received genetic counseling. One hundred forty-one (64.9%) patients had some form of prenatal genetic testing with a positivity rate of 5.7%. Postnatal characteristics were as follows: 61 (28.1%) patients were seen in prenatal consultation only and no follow-up was available. Of the remaining 156 pregnancies, 136 (86.3%) were viable and delivered at a mean gestational age of 35.2±3.8 weeks. Of these, 100 (64%) survived to discharge. Additional postnatal genetic testing was obtained in 27 infants with a positivity rate of 59%.

Conclusions

Overall perinatal mortality for this cohort as a whole was high (35.8%). While prenatal genetic testing had a limited diagnostic utility, targeted postnatal genetic testing had a much higher diagnostic yield.

Sexual function and lower urinary tract symptoms after minimally invasive endorectal pull-through in adolescent males with Hirschsprung disease

BACKGROUND

Effects of colorectal resection on sexual function and the lower urinary tract are inadequately studied in patients with Hirschsprung disease (HD). This study aimed to increase existing knowledge on sexual function and lower urinary tract symptoms (LUTS) in HD male adolescents operated with minimally invasive endorectal pull-through (ERPT).

METHODS

Non-syndromic male adolescents (12-18 years) operated with ERPT were invited to participate in this single-center cross-sectional study which included a semi-structured interview on sexual function and LUTS, a questionnaire recording LUTS, and a urodynamic study. Uroflowmetry curves were eligible for evaluation if the voided volume was >50% of expected bladder capacity. Ethical approval and informed consent were obtained.

RESULTS

Of 37 eligible male adolescents, 35 (95%) with a median age of 14.9 (12.0 -18.3) years were included. 94% had rectosigmoid aganglionosis, and 97% underwent a minimally invasive ERPT. 34 (97%) visited the outpatient clinic. The ability to get erections and to ejaculate was assessed in 25/35 (71%) adolescents. 25/25 (100%) could get an erection, and of adolescents ≥15 years 14/15 (93%) could ejaculate. 32 (91%) returned the questionnaire and underwent urodynamic studies. 15/32 (47%) reported LUTS, but most had only sporadic LUTS. 31/32 (97%) were highly satisfied with their bladder function. Sporadic urinary incontinence was reported by 4/32 (13%), but none reported social problems due to this. Of the eligible 28/32 (88%) uroflowmetry curves, 15/28 (54%) were normal.

CONCLUSIONS

Minimally invasive ERPT seems to preserve sexual function and does not induce lower urinary tract symptoms in adolescent HD males.

LEVEL OF EVIDENCE

III.

A Spectrum of Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)-Diagnostic Utility of Perinatal Autopsy

OBJECTIVE

To describe the spectrum of congenital renal anomalies and emphasize the critical role of comprehensive autopsy examination in identifying CAKUT, especially of lower urinary tract malformations correlating with prenatal imaging methods.

METHODS

Retrospective analyses of CAKUT diagnosed at fetal autopsy were analyzed over a 7-y period and correlated with prenatal imaging findings.

RESULT

Among the 255 fetal autopsies, 45 cases were detected with CAKUT. Isolated (27%), syndromic CAKUT (51%), and CAKUT associated with other system anomalies (22%) were found. Hydronephrosis, followed by cystic renal diseases and agenesis were the common renal malformations. The gastrointestinal tract (GIT) was the commonest system associated with CAKUT. Among the syndromic CAKUT, the urorectal septum malformation (URSM) was the most frequent one, followed by VACTER-L, acrorenal syndrome, and OEIS complex. When correlating prenatal USG and autopsy findings, a significant change in final diagnosis was observed in 60% of cases.

CONCLUSION

Extrarenal malformations and syndromic associations of CAKUT predominated over isolated ones. Detection of lower urinary tract anomalies in CAKUT is difficult through antenatal imaging methods if associated with oligohydramnios. In these circumstances, the perinatal autopsy has a significant role in arriving at the final diagnosis which guides the clinician in predicting the recurrence risk and the need for genetic workup.

Analysis of the operational status of the three-level referral system for urologic ultrasound screening and risk factors for renal pelvic dilatation in high-risk children

Background

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are the primary cause of end-stage renal disease in children, early diagnosis and treatment can significantly improve the kidney function. Among CAKUT, renal pelvis dilatation (RPD) due to various causes has the highest detection rate, which can be detected early by postnatal ultrasound screening. Since 2010, the Children's Hospital of Fudan University (CHFU), together with the Minhang District Maternal and Child Health Hospital (MCH) and Community Health Centres (CHCs) of Minhang District has created a three-level referral system for urological ultrasound screening. This study aims to describe the operation of a three-level referral system for ultrasound screening of CAKUT and to select risk factors of RPD in high-risk children.

Methods

The operation of the three-level referral system was assessed by analyzing the screening volume, screening rate, referral rate, and follow-up rate; risk factors of RPD in high-risk children were selected by chi-square test and multivariate logistic regression.

Results

A total of 16,468 high-risk children were screened in ten years, and the screening volume was maintained at about 1,500 cases per year; the screening rate showed a linear increase, from 36.8% in 2010 to 98.2% in 2019; the referral rate from the CHCs to the MCH was 89.9% significantly higher after 2015 than that of 84.7% from 2010 to 2015; the follow-up rate after 2015 was 71.0% significantly higher than that of 46.3% from 2010 to 2015. Multivariate logistic regression analysis showed that the risk of RPD was 1.966 times higher in males than in females, and the risk of moderate to severe RPD was 2.570 times higher in males than in females; the risk of RPD in preterm children was 1.228 times higher than that of full-term children; and the risk of RPD was 1.218 times higher in twins than in singles.

Conclusions

The screening volume of the three-level referral system has remained stable over a decade, with significantly higher screening, referral, and follow-up rates. Males, preterm, and twins are risk factors of RPD in high-risk children; males are also risk factors for moderate to severe RPD in high-risk children.

Congenital anomalies of the kidney and urinary tract (CAKUT) in critically ill infants: a multicenter cohort study

BACKGROUND

The aim of the study was to determine the prevalence of congenital anomalies of the kidney and urinary tract (CAKUT) in the neonatal intensive care unit (NICU) and to evaluate risk factors associated with worse outcomes. We hypothesized that infants with CAKUT with extra-renal manifestations have higher mortality.

METHODS

This is a cohort study of all inborn infants who were diagnosed with any form of CAKUT discharged from NICUs managed by the Pediatrix Medical Group from 1997 to 2018. Logistic and linear regression models were used to analyze risk factors associated with in-hospital mortality.

RESULTS

The prevalence of CAKUT was 1.5% among infants hospitalized in 419 NICUs. Among the 13,383 infants with CAKUT analyzed, median gestational age was 35 (interquartile range [IQR] 31-38) weeks and median birth weight was 2.34 (IQR 1.54-3.08) kg. Overall in-hospital mortality for infants with CAKUT was 6.8%. Oligohydramnios (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 2.2-9.1, p < 0.001), extra-renal anomalies (aOR 2.5, 95% CI 2.0-3.1, p < 0.001), peak SCr (aOR 1.02, 95% CI 1.01-1.03, p < 0.001) and exposure to nephrotoxic medications (aOR 1.4, 95% CI 1.1-1.7, p = 0.01) were associated with increased mortality, while a history of urological surgery or intervention was associated with lower mortality (aOR 0.6, 95% CI 0.4-0.7, p < 0.001).

CONCLUSIONS

Infants hospitalized in the NICU who have CAKUT and the independent risk factors for mortality (e.g., oligohydramnios and presence of extra-renal anomalies) require close monitoring, minimizing of exposure to nephrotoxic drugs, and timely urological surgery or intervention. A higher resolution version of the Graphical abstract is available as Supplementary information.

Maternal risk factors for congenital anomalies of the kidney and urinary tract: A case-control study

BACKGROUND

Congenital anomalies of the kidney and urinary tract (CAKUT) are significant causes of pediatric morbidity and mortality. The spectrum of CAKUT can be part of a syndrome, but most of these abnormalities occur as isolated and sporadic forms. The etiology of human CAKUT is unknown in the majority of cases. This case-control study aimed to investigate the association between maternal characteristics and the occurrence of CAKUT and specific CAKUT phenotypes.

METHODS

In this case-control study, 29,653 newborns were evaluated consecutively in a tertiary neonatal unit using the Latin American Collaborative Study of Congenital Malformations (ECLAMC) registry. Newborns without congenital anomalies were matched to CAKUT cases by sex, date, and place of birth at a ratio of 3:1. For analysis purposes, the cases were stratified into four subgroups: upper tract abnormalities (UTA), including ureteropelvic junction obstruction, vesicoureteral reflux, primary megaureter and others (n = 239), lower urinary tract obstruction (LUTO) (n = 79), cystic diseases (n = 59) and agenesis/hypodysplasia (n = 28). Multivariable logistic regression analyses were used to calculate crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for associations between the maternal risk factors and the presence of CAKUT.

RESULTS

The prevalence of non-syndromic CAKUT in our sample was 13 per 1000 live births. Data records allowed the analysis of 405 cases and 1208 controls. After adjustment by the binary regression logistic, three covariates remained associated as risk factors for the entire spectrum of CAKUT: consanguinity (Odds ratio [OR], 7.1, 95%CI, 2.4-20.4), family history of CAKUT (OR, 6.4, 95%CI, 1.9-21.3), and maternal chronic hypertension (OR, 14.69, 95%CI, 3.2-67.5) (Figure). These risk factors persisted consistently across the various CAKUT phenotypes with minor variations. Consanguinity was the only factor consistently associated with almost all CAKUT phenotypes. Maternal hypertension was associated with all phenotypes except for the agenesis/hypodysplasia group. The prevalence of CAKUT cases was 15 times higher in hypertensive mothers (3%) compared to normotensive mothers (0.2%).

CONCLUSION

Our study suggests that an increased risk of CAKUT is associated with consanguinity, a positive family history of CAKUT, and maternal hypertension. However, the prevalence of these risk factors in our cohort was rare and most cases presented as sporadic forms.

Antenatally Diagnosed Kidney Anomalies

Congenital anomalies of the kidney and urinary tract encompass a broad spectrum of developmental conditions that together account for the majority of childhood chronic kidney diseases. Kidney abnormalities are the most commonly diagnosed congenital anomaly in children, and detection of this anomaly is increasing as a result of improved antenatal care and widespread access to more sensitive screening ultrasonography. Most paediatricians will encounter children with congenital kidney anomalies across a wide spectrum of disorders, and a broad understanding of the classification, investigation, and basis of management is important to appropriately direct their care.

Anatomy and embryology of congenital surgical anomalies: Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract or "CAKUT" describes a spectrum of developmental disorders with a range of associated clinical presentations and functional consequences. CAKUT underlies the majority of chronic kidney disease and kidney replacement therapy requirement in children, but functional deterioration can also emerge in adulthood. Understanding the normal embryological processes involved in kidney development allows us to appreciate the timing and sequence of critical events implicated when things go wrong. In this review, we will describe the normal developmental mechanisms and relate this to what we currently know about the pathological processes involved in various forms of CAKUT. We will also review the proposed etiological factors, in particular genetics, involved in CAKUT.

Predictive factors for survival in patients with oligohydramnios secondary to antenatal kidney disease

BACKGROUND

Renal oligohydramnios (ROH) is caused by bilateral congenital abnormalities, either of renal parenchymal or obstructive origin. ROH is a poor prognostic factor of neonatal survival; lung hypoplasia is reported to be the main cause of mortality. We aimed to describe the fetal morbidity and pre- and postnatal mortality in case of ROH due to renal congenital pathologies and to find predictive risk factors for morbidity and mortality.

METHODS

All data were collected in Trousseau Hospital in the obstetric, neonatology, and pediatric nephrology units, from 2008 to 2020.

RESULTS

We included 66 fetuses with renal parenchymal pathologies posterior urethral valves (PUV) (N = 25), bilateral kidney agenesis (N = 10), hypodysplasia (N = 16), and polycystic kidney disease (N = 10) causing oligohydramnios identified on antenatal ultrasound. Total pre- and postnatal mortality was 76% (50/66). Mortality, excepting termination of pregnancy (TOP), was 65%. The presence of pneumomediastinum and pneumothorax was not different in survivors and non-survivors. Fetuses with kidneys having features of hypodysplasia on ultrasound at T2 and those with oligohydramnios before 32 weeks GA had a higher risk of death. There was a significant difference in plasma creatinine of the surviving patients compared to the deceased patients, from day 3 onwards (183 µmol/L [88; 255] vs. 295 µmol/L [247; 326]; p = 0.038).

CONCLUSIONS

The main differences between survivors and non-survivors among patients with "renal oligohydramnios" were oligohydramnios detection before 32 weeks GA, dysplasia detection on the second trimester ultrasound, and increase of serum creatinine from day 3 onwards. A higher resolution version of the Graphical abstract is available as Supplementary information.

Definition, diagnosis and clinical management of non-obstructive kidney dysplasia: a consensus statement by the ERKNet Working Group on Kidney Malformations

Kidney dysplasia is one of the most frequent causes of chronic kidney failure in children. While dysplasia is a histological diagnosis, the term 'kidney dysplasia' is frequently used in daily clinical life without histopathological confirmation. Clinical parameters of kidney dysplasia have not been clearly defined, leading to imprecise communication amongst healthcare professionals and patients. This lack of consensus hampers precise disease understanding and the development of specific therapies. Based on a structured literature search, we here suggest a common basis for clinical, imaging, genetic, pathological and basic science aspects of non-obstructive kidney dysplasia associated with functional kidney impairment. We propose to accept hallmark sonographic findings as surrogate parameters defining a clinical diagnosis of dysplastic kidneys. We suggest differentiated clinical follow-up plans for children with kidney dysplasia and summarize established monogenic causes for non-obstructive kidney dysplasia. Finally, we point out and discuss research gaps in the field.

Disparate phenotypes in two unfavorable pregnancies due to maternal mosaicism of a novel RET gene mutation

Mutations in RET have been found in multiple diseases including isolated and associated congenital anomalies. Here, we report a case presented with disparate phenotypes in each pregnancy but caused by the same novel mutation. Whole-exome sequencing (WES) was performed on the proband/abortion product-parental trio and a novel missense variant in RET (chr10:43615610C>G; c.2689C>G; p.Arg897Gly) was identified. The mother was a low-level somatic carrier of this new mutation, with 17.3% in blood, 19.1% in oralmucous membrane, and 15.7% in urine by droplet digital polymerase chain reaction (dd PCR). Our finding not only broadens the mutation spectrum of RET but also gives supportive genetic counseling and timely guidance on fertility choices.

Evaluation of insertion/deletion (I/D) polymorphisms of ACE gene and circulating levels of angiotensin II in congenital anomalies of the kidney and urinary tract

BACKGROUND

Congenital Anomalies of the Kidney and the Urinary Tract (CAKUT) are defined as a heterogeneous group of anomalies that resulted from defects in kidney and urinary tract embryogenesis. CAKUT have a complex etiology. Genetic, epigenetic and environmental factors have been investigated in this context. Angiotensin II is a potent vasoconstrictor and exerts an important role in kidney embryogenesis. The angiotensin-converting enzyme (ACE) converts Angiotensin I into Angiotensin II (Ang II) and ACE gene has insertion/deletion (I/D) polymorphisms that have been evaluated in several nephropathies. This study aimed to evaluate whether the I/D polymorphisms of ACE gene and the circulating levels of Ang II are associated with any CAKUT phenotype or CAKUT in general.

METHODS AND RESULTS

Our study was performed with 225 pediatric patients diagnosed with CAKUT and 210 age-and-sex matched healthy controls. ACE I/D alleles were analysed by real-time polymerase chain reaction (RT-PCR). The distribution of ACE I/D polymorphisms were compared between CAKUT patients and healthy controls, as well between ureteropelvic junction obstruction (UPJO), vesicoureteral reflux (VUR), multicystic dysplastic kidney (MCDK) phenotypes and control group. No statistical association was detected between ACE I/D polymorphism and CAKUT and UPJO, VUR, and MCDK phenotypes. In a subset of 80 CAKUT patients and 80 controls, plasma levels of Ang II were measured. No significant differences were found between CAKUT patients and controls, even in regard to comparisons of UPJO, VUR and MCDK with control group.

CONCLUSION

Although CAKUT is a complex disease and the ACE gene may exert a role in kidney embryogenesis, CAKUT was not associated with any ACE I/D polymorphisms nor with differences in plasma levels of Ang II in this Brazilian pediatric population.

Definition, diagnosis and management of fetal lower urinary tract obstruction: consensus of the ERKNet CAKUT-Obstructive Uropathy Work Group

Fetal lower urinary tract obstruction (LUTO) is associated with high mortality and postnatal morbidity caused by lung hypoplasia and impaired kidney function. Specific diagnostic features that can guide clinical approach and decisions are lacking; thus, the European Reference Network for Rare Kidney Diseases established a work group to develop recommendations regarding the clinical definition, diagnosis and management of prenatally detected LUTO. The work group recommends the use of antero-posterior diameter of renal pelvis as the most reliable parameter for suspecting obstructive uropathies and for suspecting prenatal LUTO in the presence of fetal megacystis. Regarding prenatal and postnatal prognosis of fetuses with LUTO, the risk of fetal and neonatal death depends on the presence of oligohydramnios or anhydramnios before 20 weeks' gestation, whereas the risk of kidney replacement therapy cannot be reliably foreseen before birth. Parents of fetuses with LUTO must be referred to a tertiary obstetric centre with multidisciplinary expertise in prenatal and postnatal management of obstructive uropathies, and vesico-amniotic shunt placement should be offered in selected instances, as it increases perinatal survival of fetuses with LUTO.

Structural and functional changes in the kidney caused by adverse fetal and neonatal environments

Health and disease risk in the adulthood are known to be affected by the early developmental environment. Kidney diseases are one of these diseases, and kidneys are altered both structurally and functionally by adverse pre- and perinatal events. The most known structural change is low nephron number seen in subjects born low birth weight and/or preterm. In various animal models of intrauterine growth restriction (IUGR), one of the causes of low birth weight, the mechanism of low nephron number was investigated. While apoptosis of metanephric mesenchyme has been suggested to be the cause, I showed that suppression of ureteric branching, global DNA methylation, and caspase-3 activity also contributes to the mechanism. Other structural changes caused by adverse fetal and neonatal environments include peritubular and glomerular capillary rarefaction and low podocyte endowment. These are aggravated by postnatal development of focal glomerulosclerosis and tubulointerstitial fibrosis that result from low nephron number. Functional changes can be seen in tubules, endothelium, renin-angiotensin system, sympathetic nervous system, oxidative stress, and others. As an example, I reported that aggravated nitrosative stress in a rat IUGR model resulted in more severe tubular necrosis and tubulointerstitial fibrosis after unilateral ureteral obstruction. The mechanism of various functional changes needs to be clarified but may be explained by epigenetic modifications.

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.

Non-surgical management of vesicoureteral junction obstruction: a case report

Objective:

To report the case of a pediatric patient with bilateral hydronephrosis due to vesicoureteral junction obstruction (VUJO) that was treated non-surgically and to discuss the approach of this anomaly.

Case Description:

A 25-month-old boy was referred without complaints for consultation due to prenatal ultrasound showing kidneys with cysts. He was under antibiotic prophylaxis. No family history of kidney disease and/or inherited disorders was reported. Renal ultrasound (RUS) at 2 days of life showed bilateral hydronephrosis, thus ruling out the possibility of kidney cystic disease. Dynamic renal scintigraphy (DTPA) showed marked retention of the marker in the pyelocaliceal system bilaterally, with little response to diuretic drug. He was maintained under antibiotic prophylaxis, when a new RUS showed bilateral ureteral dilatation, abrupt stenosis in the ureterovesical transition region (0.2 cm caliber), moderate bilateral hydronephrosis, and slight renal cortical thickness, confirming the diagnosis of VUJO. At 2 years and 10 months of age, DTPA showed hydronephrosis and ureteral stasis in both kidneys secondary to stenosis at the vesicoureteral junction (VUJ) level, with preservation of kidney function and slow degree of emptying. We opted for a non-surgical approach. RUS at 10 years of age showed significant improvement of all parameters, with ureteral transverse diameter of 9 mm, preserved VUJ, and age-appropriate bilateral kidney development.

Comments:

VUJO is a major cause of prenatal hydronephrosis and can trigger a deterioration of kidney function. Its treatment is still controversial but should take into account the importance of clinical follow-up and serial imaging evaluation.

Risk Factors Associated With Renal and Urinary Tract Anomalies Delineated by an Ultrasound Screening Program in Infants

OBJECTIVE

To evaluate the value of ultrasound screening for congenital anomalies of the kidney and urinary tract (CAKUT) during the early postnatal period.

METHODS

This is a prospective study that enrolled all neonates born from August 2019 to July 2020 at one medical center. Postnatal ultrasound screening was conducted in all neonates at 1, 3, and 6 months old, respectively. Information on antenatal detection and pregnancy was collected. We performed logistic regression analyses and established a predictive model to assess the potential risk factors of abnormal ultrasound screening results.

RESULTS

Postnatal ultrasound scanning in 4,877 infants identified 268 cases (5.5%) of anomalies of kidney and urinary tract by primary screening and 92 cases (1.9%) by tertiary screening. A specific diagnosis was identified in 47 cases within the 6-month screening and follow-up program. Logistic regression revealed that preterm birth, oligohydramnios, antenatal ultrasound screening anomalies, and gestational hypothyroidism were independent risk factors for the early detection of CAKUT by postnatal ultrasound screening. The above factors were adopted to develop a predictive model that showed good calibration in predicting ultrasound findings of CAKUT. Decision curve analysis demonstrated good clinical utility.

CONCLUSIONS

Postnatal ultrasound screening should be conducted in infants with risk factors associated with CAKUT. Further study on prenatal and fetal factors could help establish the predictive model for the early detection of CAKUT.

Congenital Anomalies of the Kidney and Urinary Tract in Children with Congenital Heart Defects

BACKGROUND/AIMS

To investigate the incidence and clinical characteristics of congenital anomalies of the kidney and urinary tract (CAKUT) in children with congenital heart defects (CHD).

METHODS

We retrospectively analyzed the clinical data of children with CHD with CAKUT admitted to the Shanghai Children's Medical Center affiliated with the Shanghai Jiao Tong University School of Medicine between September 2018 and March 2019. Patients underwent routine examinations for liver, kidney, and coagulation function, and urinary tract ultrasonography, and we summarized patients' clinical manifestations and imaging abnormalities.

RESULTS

A total of 1,410 children with CHD were diagnosed and treated in our hospital. The total number of patients with abnormal urogenital systems was 104, and hydronephrosis was the most common abnormality, followed by vesicoureteral reflux and duplication of the kidney and ureter. The overall prevalence of CAKUT was 7.4%. There was no statistically significant difference for maternal age, sex, parity, gestational age, and history of medication during pregnancy between the patients with CAKUT and those without CAKUT.

CONCLUSION

The incidence of CAKUT in our patients with CHD was significantly higher than that in the general population. We recommend urinary ultrasonography as a routine examination for children with CHD for early detection of CAKUT, to avoid missed diagnoses, and to initiate appropriate treatment.

Factors Associated With the Development of Chronic Kidney Disease in Children With Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of end-stage renal disease in children and adolescents. The diversity of the malformations summarized by CAKUT is high and there are numerous associated syndromes. The genetic background of these malformations remains unknown in the majority of cases. The aim of this study was to evaluate factors associated with the development of chronic kidney disease (CKD) and underlying genetic aberrations in children and adolescents with CAKUT. For this purpose, data from patients with CAKUT presented at the pediatric nephrology outpatient clinic were analyzed in a cross-sectional single-center study. Among the 405 patients, the commonest findings related to CAKUT were renal hypoplasia/dysplasia (65%), followed by hydronephrosis (43%). Forty-four percent of the patients were suffering from CKD, 6% were ranked as end-stage renal disease. In the univariate analysis, male gender and premature birth were associated with higher CKD stages (p = 0.004 resp. p < 0.001). Children with an abnormal prenatal ultrasound had more often a glomerular filtration rate of <30 ml/min/1.73 m² (p = 0.004). Patients with urinary tract infections as first symptom whereas had significant lower CKD stages (p = 0,006). In the multivariate analysis, premature birth (p = 0.033) and urinary tract infection as the first symptom (p = 0.043) were significantly associated with CKD stage ≥ II. Among the 16% of the children who have undergone genetic analyses the most frequent genetic aberration was a mutation in HNF1β-gene. These results can be used for the care of patients with CAKUT subject to factors associated with developing CKD.

Albuminuria, Hypertension, and Reduced Kidney Volumes in Adolescents Born Extremely Premature

Background: Premature birth is associated with decreased nephron number and an increased risk for chronic kidney disease (CKD). To inform the development of guidelines for kidney follow up of children born prematurely, we undertook a study of individuals born extremely preterm, with the aim of characterizing the prevalence and predictors of microalbuminuria, elevated blood pressure, and/or abnormal kidney volume in adolescence. Methods: Study participants (n = 42) were born before 28 weeks of gestation and were enrolled at birth in the Extremely Low Gestational Age Newborns (ELGAN) study. When participants were 15 years old, we obtained 2 manual blood pressures, a spot urine microalbumin measurement, and sonographic measurements of kidney length and volume. Results: Of the 42 participants, 60% were male, 52% were Caucasian (18% Hispanic), and 43% were African-American. Their median age was 15 (IQR 15, 15.3) years. In 33.3% of the cohort, blood pressure was elevated (>120/80 mmHg). Microalbuminuria (>30 mg/g) was present in 11.9% of the cohort, and kidney volume below the 10th percentile of normative data was present in 14%. Twenty-one (50%) of the sample had at least one kidney abnormality (microalbuminuria, elevated blood pressures, and/or kidney hypoplasia); these individuals were more likely to have experienced neonatal hypotension [55% vs. 17% among those with no kidney abnormality, p = 0.02]. Conclusions: Half of adolescents in this subset of ELGAN cohort have at least one risk factor of kidney disease (reduced kidney volume, microalbuminuria, and/or elevated blood pressures) at 15 years of age. This study suggests the importance of monitoring kidney outcomes in children after extremely preterm birth, especially those with a history of neonatal hypotension.

Urinary tract anomalies and urinary tract dysfunction in children with Hirschsprung disease-Is follow-up indicated?

BACKGROUND/PURPOSE

Urinary tract function in children with Hirschsprung disease (HD) is rarely considered.

AIM

to evaluate the prevalence of urinary tract anomalies and dysfunction in children with HD compared to controls.

METHODS

This was an observational cross sectional case-control study. Children with HD who underwent transanal endorectal pull-through technique (TERPT) from 2005 to 2017 were invited to participate. Ultrasound of the urinary tract was performed postoperatively. Children >4 years were asked to answer a urinary tract function questionnaire. Controls were age-matched healthy children. Ethical approval was obtained.

RESULTS

Seventy two children with HD and TERPT were included. Ultrasound was performed in 58 children (83%) post-TERPT. Ten anomalies were diagnosed in six children (10%). Structural anomalies included abnormal kidney size (7%), renal agenesis (2%), prominent calyces (2%) and renal pelvis anomaly (25). Probable acquired anomalies included hydronephrosis (2%), hydroureter (2%) and parenchymal damage (2%). One child had a prior nephrectomy owing to a Wilms' tumor. All 37 children >4 years (27 boys and 10 girls), median aged 8 years (range 4-12), answered the questionnaire as did 284 healthy controls (144 boys and 140 girls). Boys with HD reported a higher frequency of enuresis: 65% versus 9% (p = 0.001) and urinary tract infections: 18% versus 3% (p = 0.012). Girls with HD reported enuresis more frequently (60%) than healthy girls (7%) (p = 0.001). Children with HD with constipation reported enuresis more frequently (p = 0.038).

CONCLUSIONS

Urinary tract anomalies and dysfunction deserve attention in the follow-up of children with HD. We suggest screening for urinary tract anomalies and urinary tract symptoms in follow-up of children with HD.

TYPE OF STUDY

Treatment study.

LEVEL

III.

Anhydramnios in the Setting of Renal Malformations: The National Institutes of Health Workshop Summary

Anhydramnios in the setting of severe malformations of the fetal kidney and urinary tract is associated with a high incidence of stillbirths and life-threatening complications, including severe pulmonary hypoplasia, umbilical cord compression, and perinatal asphyxia. To prevent such adverse outcomes, some centers in the United States and elsewhere are offering amniotic fluid restoration for women diagnosed with anhydramnios in the setting of fetal renal malformations. The procedures include infusions of amniotic fluid substitutes (normal saline), percutaneously or through an amnioport-an implanted system for serial or continuous infusion of normal saline to maintain the desired amniotic fluid volume. The procedures are intended to prevent pulmonary hypoplasia and allow the pregnancy to progress closer to term gestation, enabling postnatal renal management, including long-term dialysis and renal transplantation. However, these procedures have not been recommended as standard of care by the professional societies because there are many knowledge gaps, including few data on short-term and long-term renal outcomes. The available diagnostic methods do not provide reliable prognostic information, and the current maternal and fetal interventions have not been standardized. To address these unresolved issues and to propose a research agenda, the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute of Diabetes and Digestive and Kidney Diseases invited a panel of experts to a workshop in August 2016. This report provides a summary of that meeting.

The protective arm of the renin-angiotensin system may counteract the intense inflammatory process in fetuses with posterior urethral valves

OBJECTIVE

Posterior urethral valve is the most common lower urinary tract obstruction in male children. A high percentage of patients with posterior urethral valve evolve to end-stage renal disease. Previous studies showed that cytokines, chemokines, and components of the renin-angiotensin system contribute to the renal damage in obstructive uropathies. The authors recently found that urine samples from fetuses with posterior urethral valve have increased levels of inflammatory molecules. The aim of this study was to measure renin-angiotensin system molecules and to investigate their correlation with previously detected inflammatory markers in the same urine samples of fetuses with posterior urethral valve.

METHODS

Urine samples from 24 fetuses with posterior urethral valve were collected and compared to those from 22 healthy male newborns at the same gestational age (controls). Renin-angiotensin system components levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Fetuses with posterior urethral valve presented increased urinary levels of angiotensin (Ang) I, Ang-(1-7) and angiotensin-converting enzyme 2 in comparison with controls. ACE levels were significantly reduced and Ang II levels were similar in fetuses with posterior urethral valve in comparison with controls.

CONCLUSIONS

Increased urinary levels of angiotensin-converting enzyme 2 and of Ang-(1-7) in fetuses with posterior urethral valve could represent a regulatory response to the intense inflammatory process triggered by posterior urethral valve.

A Predictive Model of Postnatal Surgical Intervention in Children With Prenatally Detected Congenital Anomalies of the Kidney and Urinary Tract

The aim of this study was to identify predictive factors and develop a model to assess individualized risk of postnatal surgical intervention in patients with antenatal hydronephrosis. This is a retrospective cohort study of 694 infants with prenatally detected congenital anomalies of kidney and urinary tract with a median follow-up time of 37 months. The main event of interest was postnatal surgical intervention. A predictive model was developed using Cox model with internal validation by bootstrap technique. Of 694 patients, 164 (24%) infants underwent surgical intervention in a median age of 7.8 months. Predictors of the surgical intervention in the model were: baseline glomerular filtration rate, associated hydronephrosis, presence of renal damage and the severity of renal pelvic dilatation. The optimism corrected c statistic for the model was 0.84 (95%CI, 0.82-0.87). The predictive model may contribute to identify infants at high risk for surgical intervention. Further studies are necessary to validate the model in patients from other settings.

Clinico-Biochemical Profile of Children with Congenital Anomalies of the Kidney and Urinary Tract: A Cross-Sectional Study

Background

Congenital anomalies of the kidney and urinary tract (CAKUT) are a group of disorders responsible for the majority of pediatric end-stage renal disease cases. There are only a few studies on CAKUT.

Objectives

A study was conducted to determine the clinical and biochemical profile of children with CAKUT and to estimate the prevalence and the factors associated with hypertension in CAKUT.

Methods

A cross-sectional study was conducted in a tertiary center for 18 months from March 2014 to August 2015. Demographic data were recorded, and clinical examination including blood pressure measurement was performed. Various biochemical parameters including plasma renin activity (PRA), urinary beta-2-microglobulin (B2M), and microalbuminuria were evaluated.

Results

A total of 81 patients with CAKUT were studied. Twenty-two (27%) patients were underweight, 4 (5%) patients were stunted, and 26 (32%) were both underweight and stunted. Children with bilateral disease had a higher incidence of underweight (21/44 vs. 8/37; p = 0.04; 95% CI; Fisher exact test), and both underweight and stunted (25/44 vs. 10/37; p = 0.006; 95% CI; Fisher exact test) compared to children with unilateral disease. Hypertension was found in 27% cases. No association was found between hypertension and PRA, BM2, or microalbuminuria in our study. PRA was inversely proportional to the estimated glomerular filtration rate (eGFR) (Pearson test; 95% CI; p = 0.006).

Conclusions

Bilateral disease in CAKUT was significantly associated with poor somatic growth. PRA was inversely proportional to eGFR. The prevalence of hypertension was higher in children with CAKUT than in normal children and is possibly multifactorial as it was not associated with elevated PRA, B2M, or microalbuminuria.

Evaluation of Renal Function in Children with Congenital Scoliosis and Congenital Anomalies of the Kidney and Urinary Tract

Background

The aim of this study was to compare renal function in children with congenital scoliosis and congenital anomalies of the kidney and urinary tract, with healthy children.

Material/Methods

Biochemical tests were performed before surgery (pre-therapy) and after surgery (post-therapy) in 16 children with congenital scoliosis and congenital anomalies of the kidney and urinary tract. Thirty-two healthy children were matched for age, sex, and weight (healthy controls). General renal function tests included serum electrolytes, creatinine, urea, cystatin C, and estimated glomerular filtration rate (eGFR). Tests for early renal changes included N-acetyl-beta-D-glucosaminidase (NAG), urine microalbumin, serum transferrin, immunoglobulin G (IgG), urinary alpha-1-microglobulin (A1M), and beta-2-microglobulin (B2M).

Results

Sixteen patients with congenital anomalies of the kidney and urinary tract included eight boys (mean age, 11.38±2.00 years) and eight girls (mean age, 11.00±2.78 years). There were no significant differences in renal function between the pre-therapy and post-therapy groups (P>0.05), or between the three groups (pre-therapy, post-therapy, and healthy controls). In the pre-therapy group, there were significant differences in IgG, A1M, NAG, and serum phosphate levels between boys and girls, urine microalbumin was significantly increased in girls, but not boys (P<0.05). There were no significant differences between the pre-therapy group and post-therapy group (P>0.05).

Conclusions

Routine tests of renal function were normal in children with congenital scoliosis and congenital anomalies of the kidney and urinary tract, but early changes in renal function occurred before surgical treatment, indicating long-term follow-up of renal function is recommended.

Early detection of congenital anomalies of the kidney and urinary tract: cross-sectional results of a community-based screening and referral study in China

OBJECTIVE

To establish an effective screening model of congenital anomalies of the kidney and urinary tract (CAKUT) using ultrasound among neonates in Shanghai, China.

DESIGN

Cross-sectional study.

SETTING

A three-level screening model for CAKUT in neonates based on the child healthcare system was established since 2010 in Minhang District, Shanghai, China.

PARTICIPANTS

During 2010-2015, neonates with criteria such as preterm, low birth weight and so on were eligible to participate in the study. Cases with renal pelvis dilatation (RPD) and other abnormal renal findings were managed based on presumed strategies.

MAIN OUTCOME MEASURES

The proportion of RPD and other renal and urinary tract anomalies; number of diagnosed CAKUT under integrated management, especially obstructive uropathy. The anterior-posterior renal pelvic diameter (APRPD) cut-off points for likelihood of obstructive uropathy and need for surgery.

RESULTS

A total of 8827 infants were consecutively screened. Absolute and relative rates of different degrees of RPD classified by APRPD were: mild (5-9.9 mm), 984 (11.1%); moderate (10-14.9 mm), 176 (2.0%); severe (≥15 mm), 20 (0.2%). Of 639 followed cases with RPD, 11 were diagnosed as obstructive uropathies. Of these, nine patients underwent surgery, at median age 2 months. A total 85.4% of mild, 62.5% of moderate and 30.0% of severe RPD cases resolved spontaneously. Other renal and urinary morphological abnormalities were diagnosed in 15 (0.2%) patients. The APRPD cut-off points for significant obstructive uropathy and need for surgery were 9.7 mm and 13.5 mm, respectively.

CONCLUSIONS

This three-level screening model is an effective and feasible strategy for early detection and intervention of CAKUT in the early postnatal period, especially for patients with high-grade RPD and other renal and urinary malformations. This strategy could be useful in China and other developing areas with limited medical resources.

Causes of renal oligohydramnios: impact on prenatal counseling and postnatal outcome

The presence of renal oligohydramnios (ROH) in a fetus has been associated in the past with a poor prognosis for survival, although recent studies have shown that survival has improved considerably due to the advances in neonatology and pediatric nephrology. In an article recently published in Pediatric Nephrology, evaluation of a large series by Mehler and colleagues confirms the improved prognosis, showing a survival rate of 32 of 38 (84%). In addition, only 12 of 35 (34%) neonates required renal replacement therapy. In five of these 12 children the dialysis could be terminated after the neonatal period. This study has important implications on the decision-making process and counseling of families. While 37% of families of the study opted for termination of pregnancies, palliative care was chosen by 8% of the families, representing an important option when a decision cannot be made rapidly by affected families. A multidisciplinary approach is not only necessary in the active treatment of neonates with a history of ROH but also in antenatal counseling. In this regard future efforts should establish consensus on an ethical framework for the decision-making process in ROH.

Association between cord blood cystatin C levels and early mortality of neonates with congenital abnormalities of the kidney and urinary tract: a single-center, retrospective cohort study

BACKGROUND

Some fetuses with congenital abnormalities of the kidney and urinary tract (CAKUT) have severe renal dysfunction during the prenatal period that can result in oligohydramnios, pulmonary hypoplasia, and death following birth. We hypothesized that cord blood cystatin C (CysC) levels are elevated in neonates who have life-threatening pulmonary hypoplasia and oligohydramnios due to severe renal dysfunction. In this study we compared cord blood CysC levels between a non-survivor group with CAKUT and a survivor group.

METHODS

This was a single-center, retrospective cohort study conducted between January 2007 and December 2015. Eighty-seven neonates who were prenatally diagnosed with CAKUT were included in the study. Cord blood CysC and creatinine levels were compared between the survivor and non-survivor groups at discharge from hospital.

RESULTS

Of the 87 neonates enrolled in the study, 67 survived and 21 died before discharge. Median cord blood CysC levels were higher in the non-survivor group than in the survivor group (4.28 vs. 1.96 mg/L, respectively; p < 0.001). Cord blood creatinine levels were not significantly different between the two groups. In patients with oligohydramnios (n = 28), cord blood CysC levels were significantly higher in the non-survivor group than in the survivor group (4.28 vs. 2.23 mg/L, respectively; p = 0.002).

CONCLUSIONS

In this study population, cord blood CysC levels were significantly higher in the non-survivor group with CAKUT than in the survivor group. These results suggest that cord blood CysC levels may be a good marker of the severity of renal dysfunction at birth.

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.

Posterior urethral valve in fetuses: evidence for the role of inflammatory molecules

BACKGROUND

The aim of this cross-sectional study was to investigate inflammatory biomarkers in urine samples of 24 fetuses with posterior urethral valve (PUV) collected at 22 ± 4 weeks of gestation and to compare the findings with measurements in urine samples of 22 male healthy preterm neonates at 23 ± 4 weeks (control group).

METHODS

Inflammatory biomarkers in urine were measured using a cytometric bead array [interleukin (IL)-2, IL-4, IL-6, IL-10, interferon (IFN)-γ, soluable tumor necrosis factor receptor (TNFR) 1, sTNFR2, monocyte chemoattractant protein-1/chemokine ligand 2 (MCP-1/CCL2), eotaxin/CCL11 and interferon gamma-induced protein/10/C-X-C motif chemokine 10 (IP-10/CXCL10)] and ELISA assays [TNF, IL-8/CXCL8 and transforming growth factor-beta (TGF-β)]. The Mann-Whitney test was used to compare medians. Markers of glomerular (creatinine) and tubular [beta 2 (β₂)-microglobulin, uromodulin, osmolality] functions were correlated with inflammatory biomarkers (Spearman test).

RESULTS

An intense inflammatory profile was identified, with significantly increased concentrations of urinary IL-2, IL-4, IL-6, TNF, sTNFRI, sTNFRII, IFN-γ, MCP-1/CCL2, eotaxin/CCL11 and IL-8/CXCL8 in the PUV group compared to the controls. The same was observed for the anti-inflammatory cytokine IL-10 and for the fibrogenic mediator TGF-β. In the correlation analysis, β₂-microglobulin positively correlated with the presence of MCP-1/CCL2, sTNFRI and eotaxin/CCL11 and negatively correlated with the presence of creatinine.

CONCLUSIONS

This study shows that inflammatory molecules are already increased in fetuses with PUV at the mean gestational age of 22 weeks, suggesting a physiopathological role for inflammation just after the embryological formation of the urethral membrane.

Evidence-based, ethically justified counseling for fetal bilateral renal agenesis

BACKGROUND

Not much data are available on the natural history of bilateral renal agenesis, as the medical community does not typically offer aggressive obstetric or neonatal care asbilateral renal agenesis has been accepted as a lethal condition.

AIM

To provide an evidence-based, ethically justified approach to counseling pregnant women about the obstetric management of bilateral renal agenesis.

STUDY DESIGN

A systematic literature search was performed using multiple databases. We deploy an ethical analysis of the results of the literature search on the basis of the professional responsibility model of obstetric ethics.

RESULTS

Eighteen articles met the inclusion criteria for review. With the exception of a single case study using serial amnioinfusion, there has been no other case of survival following dialysis and transplantation documented. Liveborn babies die during the neonatal period. Counseling pregnant women about management of pregnancies complicated by bilateral renal agenesis should be guided by beneficence-based judgment informed by evidence about outcomes.

CONCLUSIONS

Based on the ethical analysis of the results from this review, without experimental obstetric intervention, neonatal mortality rates will continue to be 100%. Serial amnioinfusion therefore should not be offered as treatment, but only as approved innovation or research.

Copy-number variation analysis in familial nonsyndromic congenital anomalies of the kidney and urinary tract: Evidence for the causative role of a transposable element-associated genomic rearrangement

Most congenital anomalies of the kidney and urinary tract (CAKUT) are sporadic, but familial occurrence has been described, suggesting a genetic contribution. Copy-number variations (CNVs) were detected in patients with CAKUT to identify possible novel genomic regions associated with CAKUT. CNVs were investigated in 7 children with CAKUT from three unrelated families using array comparative genomic hybridization: female monozygotic twins with bilateral duplex collecting system/vesicoureteral reflux (VUR)/unilateral renal hypodyspasia (URHD); two male siblings with VUR/URHD; 3 male second cousins, one with bilateral VUR/URHD, one with bilateral VUR and one with ureterovesical junction obstruction (UVJO). Five patients had a normal constitution of CNVs, one had a duplication of 0.2 Mb on the 5q-arm (5q23.3), probably unrelated to CAKUT, and one with UVJO had a 1.4 Mb deletion on the 17q-arm (17q12) which includes a known CAKUT gene, HNF1B. The phenotype of HNF1B deletion was extended including renal magnesium wasting. A higher coverage in transposable elements (TEs) was found in the deleted region compared with the expected density in any random genomic region. Notably, the 5′ breakpoint was mapped within a solo long terminal repeat (LTR) sequence. Moreover, highly similar members of solo LTR and mammalian interspersed repetitive (MIR) elements, as well as nucleotide sequence microhomology were detected at the breakpoint regions. In conclusion, the deletion detected in one patient suggests this genomic imbalance as causative for UVJO. A not very well known phenotype of HNF1B deletion resulting in both low urinary tract malformations and renal wasting of magnesium was described. The high load in TEs of the deleted region, the presence of highly similar elements, and the microhomology found at breakpoint regions may have contributed to the generation of the deletion. CNV analysis could reveal novel causative genomic regions in patients with CAKUT, and further studies in larger cohorts are needed.

Severe congenital anomalies of the kidney and urinary tract: epidemiology can inform ethical decision-making

OBJECTIVE

Decision-making for pregnancies complicated by severe congenital anomalies of the kidneys and urinary tract (CAKUT) are ethically challenging, partly because the outcomes are not well studied.

STUDY DESIGN

Retrospective cohort study of severe cases of CAKUT over 14 years.

RESULTS

Seventy-one of the 108 cases could be completely analyzed. Forty-six percent (n=33) infants were live-born; one-third (n=11) survived to 12 months. Twice as many non-surviving infants received a trial of therapy vs comfort care only. Two-thirds of non-survivors who received a trial of therapy died within the first 9 h of life. Live-born infants faced morbidities such as pneumothorax and neonatal dialysis.

CONCLUSIONS

Over half of pregnancies complicated by severe CAKUT ended in termination or stillbirth, but one-third of live-born infants survived to 12 months and the majority of non-survivors died within hours. This may allay concerns about prolonged and futile intensive care for parents considering a trial of therapy.

Outcome after prenatal diagnosis of congenital anomalies of the kidney and urinary tract

Congenital anomalies of the kidney and urinary tract are common findings on fetal ultrasound. The aim of this prospective observational study was to describe outcome and risk factors in 115 patients born 1995-2001. All prenatally diagnosed children were stratified into low- and high-risk group and followed postnatally clinically and by imaging at defined endpoints. Risk factors were evaluated using odds ratios. Neonatal diagnosis included pelvi-ureteric junction obstruction (n = 33), vesicoureteral reflux (n = 27), solitary mild pelvic dilatation (postnatal anteroposterior diameter 5-10 mm; n = 25), and further diagnosis as primary obstructive megaureter, unilateral multicystic dysplastic kidney, renal dysplasia and posterior urethral valves. In 38 children with prenatal isolated hydronephrosis, ultrasound normalized at median age of 1.2 years (range 0.1-9). Surgery was performed in 34 children at median age of 0.4 years (0.1-10.8). Persistent renal anomalies without surgery were present in 43 children and followed in 36 for median time of 16 years (12.2-18). Oligohydramnios and postnatal bilateral anomalies were significantly associated with surgery and impaired renal function.

CONCLUSION

The majority of children had a favourable postnatal outcome, in particular children with prenatally low risk, i.e. isolated uni- or bilateral hydronephrosis. Oligohydramnios and postnatal bilateral anomalies were risk factors for non-favourable outcome.

WHAT IS KNOWN

• In congenital anomalies of the kidney and urinary tract significantly poorer outcome is known in patients with bilateral renal hypoplasia or solitary kidney associated with posterior urethral valves. • Other factors as proteinuria and vesicoureteral reflux were associated with a higher risk of progression to chronic renal failure in these patients. What is New: • Unlike other studies giving us above-mentioned information, we included all patients with any kind of prenatally diagnosed congenital anomalies of the kidney and urinary tract. Our study shows long-term follow up (median 16 years, range 12.2-18 years), especially in patients not needing surgery, but with persistent anomalies. • During postnatal long-term follow up (median 2.2 years, range 0.1-18 years) one third each showed normalization, need of surgery or persistence of anomalies without need of surgery. Our study revealed a good prognosis in the majority of these children, in particular with prenatally low risk, i.e. isolated uni- or bilateral hydronephrosis, and revealed oligohydramnios and postnatal bilateral anomalies as risk factors for a non-favourable outcome, defined as need of surgery, persistent anomalies with impaired renal function, end stage renal failure or death.

Signs and symptoms of developmental abnormalities of the genitourinary tract

OBJECTIVE

The abnormalities of the genitourinary tract development are the leading cause of chronic kidney disease (CKD) in children. The diagnosis of this disease in Brazil is late and incomplete, which results in increased morbidity and mortality in this age group. Early diagnosis of this condition is the prerogative of generalist pediatricians, and the aim of this study was to review the clinical signs and symptoms associated with developmental abnormalities of the genitourinary tract.

DATA SOURCES

Based on the description of a symbolic clinical case, the authors conducted a non-systematic review of medical literature.

DATA SYNTHESIS

The results suggest that the following data should be used as a warning for early diagnosis of affected children: (a) combined urinary tract abnormalities (chromosomal abnormalities; sequence of malformations [VACTERLand Prune-Belly]; and musculoskeletal, digestive tract, heart, and nervous system malformations); (b) previous history (congenital anomalies of the kidney and urinary tract [CAKUT] in the family, low birth weight, and oligoamnios); (c) clinical signs (polyuria/nocturia, urinary tract infection, systemic arterial hypertension, failure to thrive, weak urinary stream, difficulty to start urination, distended bladder, non-monosymptomatic enuresis, urinary/urge incontinence, and bowel and bladder dysfunction); and (d) pre- and postnatal ultrasonographic alterations (increased anteroposterior diameter of the renal pelvis, mainly in the third trimester of pregnancy; single kidney; hydronephrosis associated with other abnormalities; and hydronephrosis with parenchymal involvement in the post-neonatal assessment).

CONCLUSION

The suggestions shown here can help the pediatrician to establish clinical hypotheses for the early diagnosis of developmental abnormalities of the genitourinary tract without resorting to expensive and invasive procedures.

Cardiac Physiology of Pregnancy

Although the physiology of the heart and vascular system has not changed, there are many things we have learned and are still learning today. Research related to heart adaptations during pregnancy has been performed since the 1930s. Since the mid-1950s, researchers began to look at changes in the maternal cardiovascular system during exercise while pregnant. Research related to exercise during pregnancy and offspring heart development began and has continued since the 1970s. We will review the normal female cardiovascular system adaptations to pregnancy in general. Additionally, topics related to maternal cardiac adaptations to pregnancy during acute exercise, as well as the chronic conditioning response from exercise training will be explored. Since physical activity during pregnancy influences fetal development, the fetal cardiac development will be discussed in regards to acute and chronic maternal exercise. Similarly, the influence of various types of maternal exercise on acute and chronic fetal heart responses will be described. Briefly, the topics related to how and if there is maternal-fetal synchrony will be explained. Lastly, the developmental changes of the fetal cardiovascular system that persist after birth will be explored. Overall, the article will discuss maternal cardiac physiology related to changes with normal pregnancy, and exercise during pregnancy, as well as fetal cardiac physiology related to changes with normal development, and exercise during pregnancy as well as developmental changes in offspring after birth.

Severe antenatally diagnosed renal disorders: background, prognosis and practical approach

Nowadays most renal disorders, especially urinary tract malformations and renal cystic disease, are diagnosed antenatally. In cases of severe bilateral disease, intrauterine renal dysfunction may lead to renal oligohydramnios (ROH), resulting in pulmonary hypoplasia which affects perinatal mortality and morbidity as well as the long-term outcome. However, some infants may only have mild pulmonary and renal disease, and advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcome even in those infants with severe ROH. Here, we review the current state of knowledge and clinical experience of patients presenting antenatally with severe bilateral renal disorders and ROH. By addressing underlying mechanisms, intrauterine tools of diagnosis and treatment as well as published outcome data, we hope to improve antenatal counselling and postnatal care. KEY SUMMARY POINTS: 1. Nowadays most renal disorders are diagnosed antenatally, especially urinary tract malformations and renal cystic disease. 2. Severe kidney dysfunction may lead to renal oligohydramnios, which can cause pulmonary hypoplasia and is a risk factor of perinatal mortality and postnatal renal outcome. However, as considerable clinical heterogeneity is present, outcome predictions need to be treated with caution. 3. Advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcomes even in infants with severe renal oligohydramnios. 4. A multidisciplinary approach with specialist input is required when counselling a family with an ROH-affected fetus as the decision-making process is very challenging.

Incidence and Risks of Congenital Anomalies of Kidney and Urinary Tract in Newborns: A Population-Based Case-Control Study in Taiwan

Congenital anomalies of the kidney and urinary tract (CAKUT) are 1 of the major factors in young adults needing renal replacement therapy, but there is little extensive assessment of their incidence and risk factors. This study aimed to evaluate trends in the incidence of and risk factors for CAKUT among all births in Taiwan.This population-based case-control study design was conducted using the Taiwan national births registry, which contains detailed information about maternal health and characteristics of newborns, supplied by health professionals. Of 1,603,794 newborns registered between 2004 and 2014, 668 infants were reported to have CAKUT. Newborns without congenital anomalies were matched with CAKUT cases by birth year, month, and Apgar score in a ratio of 5:1. Odds ratio (OR) and 95% confidence interval (CI) for developing CAKUT were calculated using a conditional multivariate logistic regression model.The incidence of CAKUT was approximately 4.2 per 10,000 births. The adjusted ORs for CAKUT in newborns associated with maternal age of 20 to 29 (OR, 2.18; 95% CI, 1.11-4.28), or 30 to 39 (OR, 2.29; 95% CI, 1.17-4.51), maternal gestational diabetes (OR, 2.22, 95% CI, 1.06-4.67), maternal thalassemia/hemochromatosis (OR, 2.67; 95% CI, 1.35-5.27), polyhydramnios or oligohydramnios (OR, 9.16; 95% CI, 5.46-15.37), birth parity >1 (OR, 0.27; 95% CI, 0.15-0.50), having a gestational age <37 weeks (OR, 1.48; 95% CI, 1.23-1.78), and being a boy (OR, 1.83; 95% CI, 1.53-2.19). Infants of mother with gestational diabetes were more likely to have congenital anomalies, small gestational age (<37 weeks) and low birth weight.CAKUT are associated with several maternal health risk factors. As Taiwan has the highest prevalence and incidence rates of end-stage renal disease in the world, these findings strongly support the need to develop professional guidelines for prenatal counseling and management of women at risk of adverse birth outcomes, to prevent kidney disease progression and reduce complications.