Mild fetal renal pelvis dilatation: much ado about nothing?

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

Development and multi-institutional validation of a deep learning model for grading of vesicoureteral reflux on voiding cystourethrogram: a retrospective multicenter study

Background

Voiding cystourethrography (VCUG) is the gold standard for the diagnosis and grading of vesicoureteral reflux (VUR). However, VUR grading from voiding cystourethrograms is highly subjective with low reliability. This study aimed to develop a deep learning model to improve reliability for VUR grading on VCUG and compare its performance to that of clinicians.

Methods

In this retrospective study in China, VCUG images were collected between January 2019 and September 2022 from our institution as an internal dataset for training and 4 external data sets as external testing set for validation. Samples were divided into training (N = 1000) and validation sets (N = 500), internal testing set (N = 168), and external testing set (N = 280). An ensemble learning-based model, Deep-VCUG, using Res-Net 101 and the voting methods was developed to predict VUR grade. The grading performance was assessed using heatmaps, area under the receiver operating characteristic curve (AUC), sensitivity, specificity, accuracy, and F1 score in the internal and external testing set. The performances of four clinicians (2 pediatric urologists and 2 radiologists) with and without the Deep-VCUG assisted to predict VUR grade were explored in external testing sets.

Findings

A total of 1948 VCUG images were collected (Internal dataset = 1668; multi-center external dataset = 280). For assessing unilateral VUR grading, the Deep-VCUG achieved AUCs of 0.962 (95% confidence interval [CI]: 0.943-0.978) and 0.944 (95% [CI]: 0.921-0.964) in the internal and external testing sets, respectively, for bilateral VUR grading, the Deep-VCUG also achieved high AUCs of 0.960 (95% [CI]: 0.922-0.983) and 0.924 (95% [CI]: 0.887-0.957). The Deep-VCUG model using voting method outperformed single model and clinician in terms of classification based on VCUG image. Moreover, Under the Dee-VCUG assisted, the classification ability of junior and senior clinicians was significantly improved.

Interpretation

The Deep-VCUG model is a generalizable, objective, and accurate tool for vesicoureteral reflux grading based on VCUG imaging and had good assistance with clinicians to VUR grading applicability.

Funding

This study was supported by Natural Science Foundation of China, "Fuqing Scholar" Student Scientific Research Program of Shanghai Medical College, Fudan University, and the Program of Greater Bay Area Institute of Precision Medicine (Guangzhou).

Outcomes of intermediate-risk hydronephrosis in pediatric patients

PURPOSE

Hydronephrosis is a common antenatal diagnosis and is present in approximately 1-5% of pregnancies. The urinary tract dilation (UTD) classification system was introduced in 2014 and stratifies post-natal hydronephrosis risk into three groups: low-risk (P1), intermediate-risk (P2), and high-risk (P3). Recommendations for P3 hydronephrosis have been established, whereas those for P1 and P2 UTD are often left to the discretion of providers with P1 considered low-grade and less concerning significant pathology. Given the obscure nature of P2 hydronephrosis, we sought to determine the natural history and outcomes of pediatric patients with P2 hydronephrosis within a single institution.

MATERIALS AND METHODS

Children <18 years old diagnosed with hydronephrosis between January 2015 and December 2018 were identified by ICD-9 and ICD-10 codes. Patients with P1 hydronephrosis, P3 hydronephrosis, known vesicoureteral reflux, complex anomalies (ex. Posterior urethral valve), neurological impairments, neurogenic bladder secondary to spinal abnormalities, and <6 months of follow-up were excluded. The development of urinary tract infection (UTI; ≥100 000 CFU/mL of bacterial growth, UA > 10 WBCs/hpf with fever >38C), need for surgical intervention (impaired renal function, worsening hydronephrosis, and/or delayed drainage on diuretic renography), and stability of hydronephrosis were collected retrospectively.

RESULTS

Eighty-seven patients [105 renal units (RU)] were included. Twenty-six patients (30%) were female and 61 (70%) were male. Of the male patients, 30 (49%) of them were circumcised. The median age at initial evaluation was 1 month, and the median duration of follow-up was 13 months. Thirty-four (32%) RU had complete resolution, 24 (23%) improved to P1 hydronephrosis, 33 (31%) remained stable, and 14 (13%) progressed to P3 hydronephrosis. The median duration to resolution and improvement was 8.5 months and 5 months, respectively. Eleven (11%) RU required surgical intervention, 10 of which underwent pyeloplasty, with a median duration to intervention of 9 months. Fifty-five patients (63%) received antibiotic prophylaxis (amoxicillin or sulfamethoxazole-trimethoprim) for a median duration of 5 months. Nine patients (10%) developed a UTI, 3 of which were taking antibiotic prophylaxis at the time of infection.

CONCLUSIONS

Intermediate-risk hydronephrosis diagnosed in the pediatric population will either improve, resolve, or remain stable during 1-year follow-up in 87% of RU. Only 11% of RU required surgical intervention, and 19% of patients developed a UTI in the absence of antibiotic prophylaxis. These findings will assist with counseling parents concerning the importance of follow-up imaging and monitoring for UTI. However, the low risk of surgical intervention is encouraging and should be discussed with the children's caretakers.

A machine learning-based approach for quantitative grading of vesicoureteral reflux from voiding cystourethrograms: Methods and proof of concept

INTRODUCTION

The objectivity of vesicoureteral reflux (VUR) grading has come into question for low inter-rater reliability. Using quantitative image features to aid in VUR grading may make it more consistent.

OBJECTIVE

To develop a novel quantitative approach to the assignment of VUR from voiding cystourethrograms (VCUG) alone.

STUDY DESIGN

An online dataset of VCUGs was abstracted and individual renal units were graded as low-grade (I-III) or high-grade (IV-V). We developed an image analysis and machine learning workflow to automatically calculate and normalize the ureteropelvic junction (UPJ) width, ureterovesical junction (UVJ) width, maximum ureter width, and tortuosity of the ureter based on three simple user annotations. A random forest classifier was trained to distinguish between low-vs high-grade VUR. An external validation cohort was generated from the institutional imaging repository. Discriminative capability was quantified using receiver-operating-characteristic and precision-recall curve analysis. We used Shapley Additive exPlanations to interpret the model's predictions.

RESULTS

41 renal units were abstracted from an online dataset, and 44 renal units were collected from the institutional imaging repository. Significant differences observed in UVJ width, UPJ width, maximum ureter width, and tortuosity between low- and high-grade VUR. A random-forest classifier performed favourably with an accuracy of 0.83, AUROC of 0.90 and AUPRC of 0.89 on leave-one-out cross-validation, and accuracy of 0.84, AUROC of 0.88 and AUPRC of 0.89 on external validation. Tortuosity had the highest feature importance, followed by maximum ureter width, UVJ width, and UPJ width. We deployed this tool as a web-application, qVUR (quantitative VUR), where users are able to upload any VCUG for automated grading using the model generated here (https://akhondker.shinyapps.io/qVUR/).

DISCUSSION

This study provides the first step towards creating an automated and more objective standard for determining the significance of VUR features. Our findings suggest that tortuosity and ureter dilatation are predictors of high-grade VUR. Moreover, this proof-of-concept model was deployed in a simple-to-use web application.

CONCLUSION

Grading of VUR using quantitative metrics is possible, even in non-standardized datasets of VCUG. Machine learning methods can be applied to objectively grade VUR in the future.

Reproductive issues in women on direct oral anticoagulants

Direct oral anticoagulants (DOACs) are replacing warfarin and other vitamin K antagonists for a wide range of indications. Advantages of DOAC therapy are fewer food and drug interactions and fixed dosing without routine laboratory monitoring, making DOACs the perfect choice especially for younger patients, in whom the main indication for anticoagulation is prevention and treatment of venous thromboembolism (VTE). Although DOACs are safer and much more convenient than other anticoagulant alternatives, their profile may have drawbacks, especially for younger female patients in whom reproductive issues need special considerations. These may include the issue of heavy menstrual bleeding (HMB) during anticoagulant therapy, the embryotoxicity risk from inadvertent DOAC exposure during pregnancy, and the prevention or planning of pregnancies during DOAC therapy. This review summarizes the most relevant evidence in this increasingly important field of women's health.

Diagnostic accuracy of an interdisciplinary tertiary center evaluation in children referred for suspected congenital anomalies of the kidney and urinary tract on fetal ultrasound - a retrospective outcome analysis

BACKGROUND

Fetal ultrasound organ screening has become a standard of care in most high-income countries. This has resulted in increased detection of congenital abnormalities, which may lead to major uncertainty and anxiety in expectant parents, even though many of them are of minor relevance. In order to optimize prenatal counselling, we introduced an interdisciplinary approach for all pregnant women referred to our center by private obstetricians for a co-assessment of suspected relevant fetal abnormalities of the kidney or urinary tract, involving both experienced prenatal ultrasound specialists and a pediatric nephrologist or urologist.

METHODS

In a retrospective analysis, we evaluated reports of intrauterine evaluation and postnatal follow-up in order to assess accuracy of explicit intrauterine diagnoses and outcome of hydronephroses according to their severity in this setting.

RESULTS

A total of 175 fetuses were examined between 2012 and 2019 and followed postnatally at our Pediatric Nephrology or Urology Department. There was a high concordance (85.9%) between explicit intrauterine and final diagnoses. Resolution rate of hydronephrosis was higher in patients with intrauterine low-grade than high-grade hydronephrosis (61.8% versus 11.9%). An etiological diagnosis was found in 62.5%, 52.0%, and 11.1% of patients with intrauterine bilateral high-grade, unilateral high-grade, and unilateral high-grade with contralateral low-grade hydronephrosis, respectively, but in none of the patients with intrauterine low-grade hydronephrosis.

CONCLUSIONS

The results of our study demonstrate that, through interdisciplinary teamwork, intrauterine assessment of the fetal kidneys and urinary tract is highly accurate and allows a good discrimination between relevant and transient/physiological hydronephroses. A higher resolution version of the Graphical abstract is available as Supplementary information.

Safety of direct oral anticoagulant exposure during pregnancy: a retrospective cohort study

BACKGROUND

Direct oral anticoagulants (DOACs) have largely replaced vitamin K antagonists in many indications for anticoagulation. Prescribed to millions of patients, including women of reproductive age, exposure to DOACs in early pregnancy is not uncommon, but data on the embryotoxic risks are scarce. We aimed to assess the risk of DOAC embryotoxicity in a large sample of reported cases.

METHODS

In this retrospective cohort study, we collected individual case reports of DOAC exposure in pregnancy from gynaecologists, haematologists, and vascular specialists starting from May, 2015. We obtained exports in April and October, 2017, August, 2018, and December, 2019, from the pharmacovigilance databases of the DOAC manufacturers, the European Medicines Agency (EMA), the German drug authority, and searched the homepage of the US Food and Drug Administration (FDA) for pregnancy exposure reports. Data from the International Society of Thrombosis and Haemostasis (ISTH) registry were obtained in August, 2018, and on July 21, 2020; data from the Teratology Information Service in Ulm, Germany, were received July 22, 2020. We also ran a systematic literature search on July 22, 2020, for cases of DOAC exposure. These data were compiled with those from our 2016 risk assessment and duplicate reports were excluded. Fetal or neonatal abnormalities were classified as a major birth defect according to the European Concerted Action on Congenital Anomalies and Twins (EUROCAT) classification and adjudicated into four categories: relation to DOAC exposure likely, possible, unlikely, or unrelated.

FINDINGS

We identified 1193 reports of DOAC exposure during pregnancy: 49 from physicians, 48 from the ISTH registry, 29 from the Teratology Information Service, 62 from the German drug authority, 536 from Bayer (extracted from the Bayer pharmacovigilance system, the WHO VigiBase, and from the FDA Adverse Event Reporting System), 87 from Boehringer Ingelheim, 16 from Daiichi Sankyo, 98 from the literature search, two from the FDA homepage search, ten from the Risk Evaluation and Mitigation Strategy Review, and 256 from the EMA reports. After excluding potential duplicates, we identified 614 unique cases of DOAC exposure in pregnancy occurring between Feb 1, 2007, and July 9, 2020, that consisted of rivaroxaban in 505 (82%) pregnancies, dabigatran in 36 (6%), apixaban in 50 (8%), and edoxaban in 23 (4%). The median duration of DOAC exposure was 5·3 weeks (IQR 4·0-7·0) into pregnancy. Information on pregnancy outcome was available in 336 (55%) of 614 pregnancies: 188 (56%) livebirths, 74 (22%) miscarriages, and 74 (22%) elective pregnancy terminations. 21 (6%; 95% CI 4-9) of 336 showed fetal abnormalities, of which 12 (4%; 2-6) were adjudicated as major birth defects potentially related to DOAC exposure.

INTERPRETATION

Although reports of pregnancy outcomes after DOAC exposure are missing important details and predominantly describe rivaroxaban exposures, the available data do not suggest that DOAC exposure in pregnancy carries a high risk of embryopathy. The 2016 ISTH guidance against elective pregnancy termination for fear of DOAC embryotoxicity and the recommendation in favour of close pregnancy surveillance is still valid. Pregnancy outcome data are inconsistently captured in pharmacovigilance databases, indicating a strong need for a more robust system of reporting.

FUNDING

None.

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.

A clinical predictive model of renal injury in children with isolated antenatal hydronephrosis

Background

Antenatal hydronephrosis (ANH) affects ∼1-5% of pregnancies. The aim of this study was to develop a clinical prediction model of renal injury in a large cohort of infants with isolated ANH.

Methods

This is a longitudinal cohort study of 447 infants with ANH admitted since birth between 1989 and 2015 at a tertiary care center. The primary endpoint was time until the occurrence of a composite event of renal injury, which includes proteinuria, hypertension and chronic kidney disease (CKD). A predictive model was developed using a Cox proportional hazards model and evaluated by C-statistics.

Results

Renal pelvic dilatation (RPD) was classified into two groups [Grades 1-2 (n = 255) versus Grades 3-4 (n = 192)]. The median follow-up time was 6.4 years (interquartile range 2.8-12.5). Thirteen patients (2.9%) developed proteinuria, 6 (1.3%) hypertension and 14 (3.1%) CKD Stage 2. All events occurred in patients with RPD Grades 3-4. After adjustment, three covariables remained as predictors of the composite event: creatinine {hazard ratio [HR] 1.27, [95% confidence interval (CI) 1.05-1.56]}, renal parenchyma thickness at birth [HR 0.78(95% CI 0.625-0.991)] and recurrent urinary tract infections [HR 4.52 (95% CI 1.49-13.6)]. The probability of renal injury at 15 years of age was estimated as 0, 15 and 24% for patients assigned to the low-risk, medium-risk and high-risk groups, respectively (P < 0.001).

Conclusion

Our findings indicate an uneventful clinical course for patients with Society for Fetal Urology (SFU) Grades 1-2 ANH. Conversely, for infants with SFU Grades 3-4 ANH, our prediction model enabled the identification of a subgroup of patients with increased risk of renal injury over time.

[Fetal anteroposterior renal pelvic diameter for predicting antenatal hydronephrosis requiring postnatal surgery]

OBJECTIVE

To assess the value of fetal anteroposterior renal pelvic diameter (APD) in predicting antenatal hydronephrosis requiring surgical treatment after birth.

METHODS

A total of 525 cases of antenatal hydronephrosis detected by prenatal ultrasonography (ultrasound index APD ≥ 4 mm in the second trimester and APD ≥ 7 mm in the third trimester) in Zhejiang Prenatal Diagnosis Center from June 2007 to June 2018 were retrospectively analyzed. ROC curve was used to analyze the relationship between these ultrasound indicators and the requirement for surgical treatment after birth.

RESULTS

There were 162 cases (30.9%) diagnosed in the second trimester and 363 cases (69.1%) diagnosed in the third trimester; 131 cases were diagnosed pathologically after birth, of which 121 finally underwent surgical treatment. The area under ROC curve (AUC) of APD in middle pregnancy for prediction of requiring surgery 1-12 years after birth was 0.910; the cut-off value of APD was 8.45 mm with a sensitivity of 97.1%, specificity of 70.9%, positive predictive value (PPV) of 47.9%, and negative predictive value (NPV) of 98.9%. The AUC of APD in late pregnancy for prediction of requiring surgery 1-12 years after birth was 0.800; the cut-off value of APD was 12.25 mm with a sensitivity of 66.7%, specificity of 81.2%, PPV of 51.7%, and NPV of 89.1%.

CONCLUSIONS

APD in pregnancy can be used to predict whether the fetus with hydronephrosis needs surgical treatment after birth, and the prediction value of APD in the middle pregnancy is better.

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.

Management of antenatally detected kidney malformations

Congenital anomalies of the kidneys and the urinary tract (CAKUT) are one of the most common sonographically identified antenatal malformations. Dilatation of the renal pelvis accounts for the majority of cases, but this is usually mild rather than an indicator of obstructive uropathy. Other conditions such as small through large hyperechogenic and/or cystic kidneys present a significant diagnostic dilemma on routine scanning. Accurate diagnosis and prediction of prognosis is often not possible without a positive family history, although maintenance of adequate amniotic fluid is usually a good sign. Both pre- and postnatal genetic screening is possible for multiple known CAKUT genes but less than a fifth of non-syndromic sporadic cases have detectable monogenic mutations with current technology. In utero management options are limited, with little evidence of benefit from shunting of obstructed systems or installation of artificial amniotic fluid. Often outcome hinges on associated cardiac, neurological or other abnormalities, particularly in syndromic cases. Hence, management centres on a careful assessment of all anomalies and planning for postnatal care. Early delivery is rarely indicated since this exposes the baby to the risks of prematurity in addition to their underlying CAKUT. Parents value discussions with a multidisciplinary team including fetal medicine and paediatric nephrology or urology, with neonatologists to plan perinatal care and clinical geneticists for future risks of CAKUT.

Diagnostic Value of Anteroposterior Diameter of Renal Pelvis for Predicting Postnatal Surgery: A Systematic Review and Meta-Analysis

PURPOSE

We assessed the diagnostic value of anteroposterior diameter of the fetal renal pelvis in predicting postnatal surgery.

MATERIALS AND METHODS

PubMed®, Embase® and Cochrane Library databases were searched for articles comparing patients who underwent surgery or conservative therapy with 15 mm anteroposterior diameter as a cutoff value. Data on sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic OR and area under the summary ROC curve were used to evaluate the diagnostic value of anteroposterior diameter of the fetal renal pelvis in predicting postnatal surgery.

RESULTS

Five studies involving a total of 1,159 patients met the inclusion criteria. The summary sensitivity and specificity were 0.81 (95% CI 0.60 to 0.92) and 0.78 (95% CI 0.68 to 0.86), respectively. Positive and negative likelihood ratios of anteroposterior diameter were 3.73 (95% CI 2.75 to 5.06) and 0.24 (95% CI 0.11 to 0.52), respectively. Diagnostic OR of anteroposterior diameter for predicting postnatal surgery was 13.33 (95% CI 6.61 to 26.89) and area under the summary ROC curve was 0.85 (95% CI 0.82 to 0.88). Subgroup analysis suggested postnatal anteroposterior diameter was associated with higher diagnostic OR compared to prenatal anteroposterior diameter for predicting postnatal surgery (ratio between prenatal and postnatal anteroposterior diameter 0.27, 95% CI 0.09 to 0.86, p = 0.026).

CONCLUSIONS

Using 15 mm anteroposterior diameter of the fetal renal pelvis as a cutoff showed moderate diagnostic value for predicting postnatal surgery.

The antenatal urinary tract dilation classification system accurately predicts severity of kidney and urinary tract abnormalities

BACKGROUND

Urinary tract dilation (UTD) is a commonly diagnosed prenatal condition; however, it is currently unknown which features lead to benign and resolving or pathologic abnormalities. A consensus UTD classification system (antenatal UTD classification, UTD-A) was created by Nguyen et al. in 2014 [1], but has not yet been validated.

OBJECTIVE

To evaluate the ability of the UTD-A system to identify kidney and urinary tract (KUT) abnormalities, assess whether UTD-A can predict severity of KUT conditions, and perform a cost analysis of screening ultrasound (US).

METHODS

A retrospective single-center study was conducted at an academic medical center. Inclusion criteria were: neonates in the well or sick nursery who had a complete abdominal or limited renal US performed in the first 30 days of life between January 01, 2011 and December 31, 2013. Data were collected on prenatal US characteristics from which UTD-A classification was retrospectively applied, and postnatal data were collected up to 2 years following birth.

RESULTS

A total of 203 patients were identified. Of the 36 abnormal postnatal KUT diagnoses, 90% were identified prenatally as UTD A1 or UTD A2-3. The remaining 10% developed postnatal KUT abnormalities due to myelomeningocele, such as VUR or UTD, which were not evident prenatally. Overall sensitivity and specificity of the UTD-A system was 0.767 (95% CI 0.577, 0.901) and 0.836 (95% CI 0.758, 0.897), respectively, when resolved UTD was counted as a normal diagnosis. Postnatal diagnoses differed by UTD-A classification as shown in the Summary fig. Of all the obstructive uropathies, 90.9% occurred in the UTD A2-3 class and none occurred in UTD-A Normal. Rate of postnatally resolved UTD was significantly higher in the UTD A1 group (78%) compared with UTD A2-3 (31%) or UTD-A Normal (12%, all P < 0.001). There was a notable trend towards more UT surgeries, UTI, and positive VUR among UTD A2-3 patients, but statistical significance was limited by a small number of patients.

CONCLUSIONS

This study found that the UTD-A classification system revealed important differences in the severity of UTD abnormalities. With repeated validation in larger cohorts, the UTD-A classification may be used to offer a prognosis for parents regarding prenatally diagnosed KUT conditions. Larger prospective studies should be designed to validate whether the UTD-A system can predict postnatal events related to UTD morbidity such as need for UT-related surgery or UTI.

Pregnancy outcome in patients exposed to direct oral anticoagulants - and the challenge of event reporting

Today, direct oral anticoagulants (DOAC) are widely used alternatives to Vitamin-K antagonists (VKA). Women of reproductive age may become pregnant during anticoagulation and, while VKA carry an embryotoxic potential, the risk of DOAC embryopathy is unknown. As a result, some patients elect to terminate pregnancy for fear of DOAC embryotoxicity. To assess the risk of DOAC embryopathy, we reviewed cases of DOAC exposure in pregnancy collected from physicians, literature and pharmacovigilance systems of drug authorities and manufacturers. A total of 357 reports including duplicates were available from which 233 unique cases could be identified. Information on pregnancy outcome was available in only 137/233 cases (58.8 %): 67 live births (48.9 %); 31 miscarriages (22.6 %); 39 elective pregnancy terminations (28.5 %). In 93 cases (39.9 %) no outcome data were available (including 3 cases of ongoing pregnancy). Of the 137 pregnancies with reported outcomes, seven showed abnormalities (5.1 %) of which three (2.2 %) could potentially be interpreted as embryopathy: live birth with facial dysmorphism; miscarriage in week 10 with limb abnormality; elective pregnancy termination due to a foetal cardiac defect in a woman who had to terminate a previous pregnancy due to Fallot tetralogy. Within its limitations (small numbers, incomplete outcome data) our results do not indicate that DOAC exposure in pregnancy carries a high risk of embryopathy or that DOAC exposure per se should be used to direct patient counselling towards pregnancy termination. Pregnancy outcome data are inconsistently captured in pharmacovigilance databases indicating the strong need for a more robust system of reporting.

Neonatal and early infancy management of prenatally detected hydronephrosis

Hydronephrosis discovered during prenatal ultrasound will often resolve spontaneously; however, it should be evaluated in the postnatal period in a manner commensurate with its risk of renal injury. Early intervention is appropriate in cases of bladder outlet obstruction or the severely obstructed solitary kidney. In most other cases, it is both safe and reasonable to allow the possibility of spontaneous improvement with the intensity of follow-up based on the severity of the hydronephrosis. Clinical decision making should be a shared process between families and caregivers.

Teaching of the Society for Fetal Urology grading system for pediatric hydronephrosis is improved by e-Learning using Computer Enhanced Visual Learning (CEVL): A multi-institutional trial

INTRODUCTION

It is unclear how clinicians learn to grade pediatric hydronephrosis (HN) and how effective their training has been. We sought to: 1. Assess how clinicians learn to grade HN and their confidence in their training and abilities and 2. To assess Computer Enhanced Visual Learning (CEVL) e-Learning to learn the Society for Fetal Urology (SFU) grading system for pediatric HN.

METHODS AND MATERIALS

A multi-institutional online survey was distributed to pediatric urologists, nephrologists, and radiologists. Respondents used a 6-point Likert scale (0 = not confident to 5 = very confident) to assess their confidence in knowledge of the criteria, indications, and ability to grade HN, and how they learned to grade. Participants assigned SFU grades to 15 neonatal ultrasounds (US). A CEVL module on the SFU grading system was accessed and a post-CEVL survey completed. Changes in confidence and accuracy of grading were compared before and after CEVL e-Learning.

RESULTS

The most common method of learning was "casually during training" (44.5%). Significant increases in confidence in knowledge of criteria, indications, and ability to grade, as well as the accuracy of grading were seen following CEVL e-Learning (Figure A and B).

DISCUSSION

Although the SFU grading system is considered the predominant grading system for HN, its application in clinical practice has been inconsistent. While this may be due to the grading system itself, it is possible that deficient training and confidence are the root causes. Our data supports this by demonstrating that most clinicians receive only casual training and accordingly, report low confidence in their knowledge and ability to grade HN. Therefore, we conclude that there exists a strong need to improve the teaching of the SFU grading system. e-Learning has been shown to be effective in teaching difficult topics and skills. We demonstrate that e-Learning with CEVL is effective in increasing both the confidence and accuracy of SFU grading of pediatric HN. Limitations of our study include a small sample size, low response rate, and discrepant participation. Furthermore, we did not assess the extent to which the CEVL module was used or include a control group learning through traditional means. Therefore, we were unable to evaluate the efficiency of learning or be certain that the improvements seen were derived exclusively from CEVL.

CONCLUSION

Current training in SFU grading of HN is mostly unstructured and inaccurate grading is common. Learners who use CEVL show improvements in their confidence and ability to SFU grade HN.

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.

Prenatal anteroposterior pelvic diameter cutoffs for postnatal referral for isolated pyelectasis and hydronephrosis: more is not always better

PURPOSE

Congenital hydronephrosis and isolated pyelectasis are frequently diagnosed by prenatal ultrasound. About 80% of cases resolve spontaneously in early childhood. Currently there is no agreed on protocol for prenatal followup. Most clinicians use a renal pelvis anteroposterior diameter of greater than 4 mm as a threshold for identifying isolated pyelectasis and hydronephrosis at 33 weeks of gestation or anteroposterior diameter greater than 7 mm at 40 weeks of gestation. We sought to determine a fetal renal pelvis diameter cutoff at 20 and 30 weeks of gestation that would be able to predict significant nephron uropathy requiring surgery.

MATERIALS AND METHODS

Our protocol included 2 prenatal ultrasounds at 20 and 30 weeks of gestation and 3 postnatal ultrasounds at ages 1, 6 and 12 months. Between January 2009 and December 2011 we evaluated 149 prenatal cases (130 males, 19 females) of isolated pyelectasis and 41 cases (28 males, 13 females) of hydronephrosis with a renal pelvis anteroposterior diameter of greater than 4 mm at 20 weeks of gestation.

RESULTS

For isolated pyelectasis we identified cutoffs of 6 mm at 20 weeks of gestation (100% sensitivity, 84.3% specificity) and 10 mm at 30 weeks of gestation (100% sensitivity, 91.9% specificity). For hydronephrosis we identified cutoffs of 10 mm at 20 weeks of gestation (100% sensitivity, 86.1% specificity) and 12 mm at 30 weeks of gestation (100% sensitivity, 66.7% specificity).

CONCLUSIONS

Using these thresholds, we could avoid a significant number of followup ultrasounds in the prenatal and postnatal periods, as well as invasive postnatal tests (ie voiding cystourethrography and mercaptoacetyltriglycine scintigraphy) without missing even a single case of obstructive nephropathy requiring surgery.

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.

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

BACKGROUND

Congenital abnormalities of the kidney and urinary tract (CAKUT) are significant causes of morbidity. The aim of the study was to determine predictive factors of mortality in newborns with CAKUT.

METHODS

All 29,653 consecutive newborns hospitalized in a tertiary neonatal unit between 1996 and 2006 were evaluated. The main outcome was neonatal mortality. The variables analyzed as risk factors were maternal age, first pregnancy, low birth weight (LBW), prematurity, oligohydramnios, and CAKUT associated with other malformations (Associated CAKUT).

RESULTS

CAKUT was detected in 524 newborns, with an overall prevalence of 17.7 per 1,000 live births. A total of 325 (62%) cases were classified as urinary tract dilatation, 79 (15.1%) as renal cystic disease, and 120 (22.9%) as other subgroups. In the urinary tract dilatation subgroup, independent risk factors for early mortality were Associated CAKUT [odds ratio (OR) 20.7], prematurity (OR 4.5) LBW (OR 3.8), oligohydramnios (OR 3.0), and renal involvement (OR 3.0). In the renal cystic disease subgroup, two variables remained associated with neonatal mortality: LBW (OR 12.3) and Associated CAKUT (OR 21.4).

CONCLUSION

The presence of extrarenal anomalies was a strong predictor of poor outcome in a larger series of infants with CAKUT.

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.

Urine IL-8 concentrations in infectious and non-infectious urinary tract conditions

Urine IL-8 concentrations are known to be elevated in urinary tract infection (UTI), as well as in vesicoureteral reflux (VUR) even in the absence of infection. In this study we further investigated urine IL-8 in infants with congenital anomalies of the kidneys and urinary tract and with antenatally diagnosed isolated pelvic dilatation. Urine IL-8 was measured in 159 infants aged 1 month to 1 year with acute UTI (group A, n = 26), resolved UTI (group B, n = 16), VUR without recent UTI (group C, n = 44), non-VUR congenital urinary anomalies without recent UTI (group D, n = 30), isolated antenatal pelvic dilatation (group E, n = 14) and in infants without known urinary tract condition (control group F, n = 29). Median values of urine IL-8/creatinine levels were 61.5, 4.64, 15.5, 14.3, 1.06 and 4.19 pg/μmol in groups A, B, C, D, E and F respectively. Compared with the control group, urine IL-8 was elevated in infants with acute UTI, VUR without acute UTI and congenital anomalies without acute UTI (p < 0.0001; p < 0.005; and p = 0.027 respectively), but not in infants with resolved UTI or with antenatal pelvic dilatation. Urine IL-8 levels are elevated in a variety of infectious and non-infectious urinary tract conditions, and hence may serve as a sensitive but not specific screening biomarker of urinary tract diseases.

Urinary levels of TGF β-1 and of cytokines in patients with prenatally detected nephrouropathies

This study aimed to identify noninvasive biomarkers of clinically significant nephrouropathies in patients with antenatal renal and/or urinary tract alterations. Spot-urine levels of interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) were measured in 100 patients with antenatal detected nephrouropathies. Patients were divided in idiopathic hydronephrosis (n = 47), urinary tract malformations (n  = 35), and dysplastic kidneys (n = 18). Urinary concentrations of TGF-β1, IL-6, and TNF-α were compared between groups according to clinical and image findings. Receiver-operating characteristic (ROC) curves were analyzed for the overall diagnostic accuracy of TGF-β1, IL-6, and TNF-α levels in discriminating infants with nephrouropathies. No significant differences in urinary TGF- β1, IL-6, and TNF-α levels were found in the comparison between the groups. TGF-β1 levels tended to be higher in patients with renal hypodysplasia compared to idiopathic hydronephrosis (p = 0.07). Twenty-nine patients had reduced DMSA uptake. In these cases, absolute urinary concentration of TGF-β1 and levels standardized for creatinine were significantly higher than in patients with normal DMSA uptake, while IL6 and TNF-α did not differ between groups. Urinary cytokine measurements were not useful as a screening test for clinically significant nephrouropathies. Conversely, increased concentrations of TGF-β1 pointed out to renal damage as indicated by reduced DMSA uptake.

Prenatal genetic screening and diagnosis for pediatricians

PURPOSE OF REVIEW

Prenatal genetic screening and diagnostic testing can identify many disorders that will require specialized newborn care and follow-up. Pediatricians should be aware of recent advances in testing that may have implications for their patients and families.

RECENT FINDINGS

Over the last half decade, there have been important changes in the breadth and depth of prenatal screening and diagnostic procedures. Carrier screening for selected genetic disorders is now offered routinely to pregnant women or those contemplating pregnancy. Newly developed strategies for first-trimester screening for fetal chromosome abnormalities have improved the detection rate for these disorders, while maintaining a low screen-positive rate. The American College of Obstetricians and Gynecologists and the American College of Medical Genetics now recommend that invasive prenatal diagnostic testing be made available to all pregnant women, regardless of age or prenatal screening results. And prenatal ultrasound findings of unknown clinical significance require that pediatricians provide appropriate follow-up in the newborn period and beyond.

SUMMARY

Prenatal genetic screening and diagnostic tests are changing rapidly, and results of these tests may impact the postnatal evaluation and treatment strategies for pediatric care.

Ultrasound Scanning in Fetal Renal Pelvis Dilatation: not only Hydronephrosis

Pelvic dilatation is the alteration of the urinary tractmost frequently detected by maternal-fetalultra-sound. Hydronephrosis is not a diagnosis; it is an imagefinding. The diagnosis is the cause that produces it. Since pelvic dilatation is relatively frequent in thenormal fetus, and the definition and diagnosis of hy-dronephrosis are difficult, once it is detected, adequate follow-up is required. Therefore, it is important for the urologist and obstetrician to understanddifferential diagnosis and clinical implications in order to offer an accurate counselling to the parents.

Predictive factors for vesicoureteral reflux and prenatally diagnosed renal pelvic dilatation

PURPOSE

We sought to identify predictive factors for primary vesicoureteral reflux among infants with prenatally detected renal pelvic dilatation.

MATERIALS AND METHODS

A total of 250 neonates were diagnosed with isolated renal pelvic dilatation between 1999 and 2008, and followed prospectively. The main event of interest was presence of moderate to severe reflux (grade III to V). Diagnostic odds ratio, sensitivity, specificity, and diagnostic accuracy (assessed by AUC) of fetal and postnatal renal pelvic dilatation were determined. Severity of dilatation was classified by Society for Fetal Urology grade. Binary logistic regression was performed to identify variables significantly associated with vesicoureteral reflux.

RESULTS

A total of 23 patients (9.2%) had primary vesicoureteral reflux, of whom 16 had grade III to V disease. Diagnostic accuracy was 0.70 (95% CI 0.63 to 0.75) for fetal and 0.65 (95% CI 0.59 to 0.71) for postnatal renal pelvic dilatation. Combined results of fetal and postnatal renal pelvic dilatation were also assessed. When both tests less than 10 mm were considered negative indicators of moderate to severe vesicoureteral reflux sensitivity increased to 97% and diagnostic odds ratio to 19.1. After adjustment by logistic regression only Society for Fetal Urology grade greater than I and ureteral dilatation were variables independently associated with grade III to V reflux.

CONCLUSIONS

Fetal and postnatal renal pelvic dilatation was a poor predictor of vesicoureteral reflux. Nevertheless, diagnostic accuracy regarding clinically significant vesicoureteral reflux improved when fetal and postnatal renal pelvic dilatation less than 10 mm was considered a negative indicator of reflux.