Antenatal minimal hydronephrosis: is its follow-up an unnecessary cause of concern?

Renal cortical transit time in the evaluation of prenatally detected presumed pelvi ureteric junction like obstruction: A systematic review

Introduction

Differentiating nonobstructive from obstructive dilatation of the kidney is a clinical dilemma in prenatally detected hydronephrosis. Many radionuclide renogram parameters have been used to differentiate obstructed from non-obstructed units, including cortical transit time (CTT). We evaluate the role of CTT in identifying obstruction through a systematic review.

Methods

A literature search of the MEDLINE, MEDLINE In-Process, and MEDLINE Epub Ahead of Print, EMBASE, Google scholar, Pub Med, and Cochrane Library was done using key words - radionuclide renogram, CTT, parenchymal transit time, cortical transit, renography to identify articles on the subject. The identified articles were assessed for appropriateness and reviewed.

Results

The initial search yielded a total of 1583 articles, after adding the articles from references and applying the inclusion and exclusion criteria a total of 28 articles were selected. CTT showed good inter observer agreement in identifying obstruction. The use of CTT as a single parameter for determining the need for surgery and to identify those kidneys which will have functional improvement after surgery has been evaluated and has been found to be useful. CTT is best used in conjunction with ultrasonography to make clinical decisions.

Conclusion

The commonly used visual method of estimating the CTT, is a promising parameter for the evaluation of prenatally detected pelviureteric junction obstruction. Further well-designed multicenter prospective studies are needed to establish it as the most specific parameter to differentiate obstructive from nonobstructive dilatation of the pelvicalyceal system.

Postnatal management of children with antenatal hydronephrosis

Background

Postnatal management of infants with antenatal hydronephrosis (ANH) is still one of the most controversial issues. The majority of infants with ANH are asymptomatic with only few children who develop renal insufficiency. Thus, the biggest challenge for pediatric urologists is to distinguish children who will require further investigations and possible intervention prior to the development of symptoms, complications or renal damage in a cost effective manner without exposing them to the hazards of unnecessary investigations.

Main body

In this review article, literature on ANH were reviewed to present the current suggestions, recommendations, guidelines and their rational for postnatal management of ANH. It is agreed that a large portion of infants with ANH will improve; thus, the protocol of management is based mainly on observation and follow-up by ultrasound to detect either resolution, stabilization or worsening of hydronephrosis. The first 2 years of life are critical for this follow-up as the final picture is mostly reached during that period. Advanced imaging using voiding cystourethrography or renal scintigraphy are required for children at risk. Then, surgical intervention is selected only for a subgroup of these infants who showed worsening of hydronephrosis or renal function.

Conclusions

The protocol of management is based mainly on observation and follow-up by US to detect either resolution, stabilization or worsening of hydronephrosis. Postnatal evaluation should be performed for any neonate with a history ANH at any stage during pregnancy even if it was resolved during third trimester. Exclusion of UTI should be performed by urinalysis for all cases followed by urine culture if indicated. Serum creatinine should be performed especially in patients with bilateral ANH. US is the initial standard diagnostic imaging technique. Other imaging modalities like VCUG and nuclear renal scans may be required according to the results of the US evaluation. The most important items in decision making are the presence of bilateral or unilateral hydronephrosis, presence or absence of hydroureter, presence of lower urinary tract obstruction and degree of hydronephrosis on the initial postnatal US. Then an intervention is selected only for a subgroup of these patients who showed deterioration in renal function or degree of hydronephrosis or were complicated by UTIs. All these recommendations are based on the available literature. However, management of ANH is still a controversial issue due to lack of high evidence-based recommendations. Randomised controlled studies are still needed to provide a high level evidence for different aspects of management.

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.

Value of renal pelvic diameter and urinary tract dilation classification in the prediction of urinary tract anomaly

BACKGROUND

The aim of this study was to identify the cut-offs of postnatal anteroposterior renal pelvic diameter (APRPD), according to the urinary tract dilation (UTD) classification system, to identify the predictors of final diagnosis of UTD and the need for surgery.

METHODS

A total of 260 infants (336 renal units) with prenatally detected UTD were prospectively evaluated on serial ultrasonography by the same radiologist. Additional voiding cystourethrography and scintigraphy was done according to the clinical algorithm.

RESULTS

Prenatal and postnatal APRPD in patients with transient dilation were significantly lower than in those with urinary tract anomalies (UTA). On follow up, the slope of decrease in APRPD was significantly higher in transient dilation compared with UTA. APRPD 10 mm at first-month ultrasonography, predicted UTA with a sensitivity of 83.1%, and specificity of 71.1%. On multivariate analysis the likelihood of surgical intervention and final diagnosis were predicted independently by the UTD system risk group.

CONCLUSIONS

Careful ultrasonography evaluation can avoid unnecessary testing in patients with transient or clinically insignificant dilation. The UTD classification system is valid for evaluation of postnatal hydronephrosis and is reliable in predicting the need for surgical intervention.

Diagnostic value of urinary RBP, ALB and AQP2 in neonatal hydronephrosis and the relationship with expression of MCP-1 in the prenatal maternal peripheral blood

Diagnostic value of urinary retinol binding protein (RBP), albumin (ALB) and aquaporin-2 (AQP2) in neonatal hydronephrosis and their relationship with the expression of monocyte chemoattractant protein 1 (MCP-1) in the prenatal maternal peripheral blood was investigated. Forty-six child patients with hydronephrosis admitted to Hongqi Hospital Affiliated to Mudanjiang Medical College from December 2016 to November 2017 were selected as the observation group and the control included 46 normal newborn infants. The urinary RBP, ALB, AQP2 and the expression of MCP-1 in the prenatal maternal peripheral blood in the two groups were compared. The diagnostic value of the combination of urinary RBP, ALB and AQP2 for the neonatal hydronephrosis was accessed through the area under curve (AUC). The changes of urinary RBP, ALB and AQP2 of child patients were observed and the correlations between RBP, ALB, AQP2 and MCP-1 were analyzed. The concentrations of RBP and ALB in the observation group were obviously increased compared to those in the control group. The AQP2 concentration in the observation group was lower than that in the control group. In the observation group, the MCP-1 level in the prenatal maternal blood was significantly higher than that in the control group (P<0.05). After treatment, the concentration of RBP and ALB in the child patients were significantly decreased and AQP2 concentration was increased compared with that before treatment (P<0.05). The AUC of the diagnosis combining with RBP, ALB and AQP2 was 0.913. RBP and ALB were positively correlated to MCP-1 in the prenatal maternal peripheral blood and there was a negative correlation between AQP2 and MCP-1 (P<0.05). In conclusion, urinary RBP, ALB and AQP2 can be regarded as markers for the diagnosis of the neonatal hydronephrosis and they are also closely related to the MCP-1 level in the prenatal maternal peripheral blood.

Outcomes of Isolated Antenatal Hydronephrosis at First Year of Life

Objectives

To compare the grade of hydronephrosis between the antenatal and first postnatal ultrasound (US) and their clinical outcomes.

Methods

This retrospective study included all cases of isolated hydronephrosis detected by antenatal US from August 2005 to February 2011. Hydronephrosis was classified based on the standard criteria into mild, moderate, or severe. Cases associated with other major congenital anomalies were excluded. All patients were followed-up postnatally and outcomes available were analyzed at one year of age.

Results

A total of 105 cases were included out of which 83 (79.0%) were males and 22 (20.9%) were females with a median gestational age of 38 weeks. First postnatal US of 105 cases showed that 20 (19.0%) were free of hydronephrosis, 39 (37.1%) had mild, 29 (27.6%) moderate, and 17 (16.1%) had severe hydronephrosis. Half (50.4%) of hydronephrosis cases improved in their clinical presentation while 13.3% showed deterioration and 36.3% remained the same. Almost half of all cases (52 cases) were diagnosed by US at the end of first year without any effect on renal function.

Conclusions

Antenatal and postnatal US are sensitive tools for detecting hydronephrosis as well as for postnatal counseling. Fetal anatomy US is usually done at 18 weeks gestation and if this reveals any evidence of hydronephrosis, the patient is followed according to the severity. Postnatal US is not done routinely for cases where hydronephrosis resolves completely during pregnancy. Although newborns with antenatal hydronephrosis due to secondary causes are at greater risk for renal impairment, surgical intervention reserves renal function.

Comparative effectiveness of a pilot patient-centered ultrasound report in the management of hydronephrosis

PURPOSE

Hydronephrosis is a common pediatric abnormality and can be associated with substantial parental anxiety, especially in the prenatal period. Radiology reports contain complex content that can be difficult for lay audiences to comprehend, potentially contributing to parental distress.

MATERIALS AND METHODS

We developed and piloted a patient-centered radiology report (PCRR) for renal ultrasounds (US) in children with hydronephrosis (Figure). We obtained consensus from a multidisciplinary panel of experts regarding critical US report components. A parent focus group provided input regarding syntax and formatting of a PCRR, incorporating elements deemed valuable by the expert panel. We prospectively recruited parents of children who underwent US for hydronephrosis and randomized parents to receive either the PCRR + standard report (SR) or SR alone. Web-based surveys assessed self-efficacy and knowledge of US elements.

RESULTS

Our pilot study included 20 SR patients and 24 PCRR patients, with no difference in demographic or disease characteristics between groups. Self-efficacy scores were uniformly high in both groups (p = 0.79). PCRR parents trended towards increased accuracy in identifying presence of severity (88% vs. 70%; p = 0.15) and bilaterality (67% vs. 45%; p = 0.15), with minimal difference in identifying parenchymal pathology (75% vs. 70%; p = 0.71) and bladder abnormalities (88% vs. 85%; p = 0.81). Parents were more confident in their ability to understand the PCRR (92% vs. 60%; p = 0.01).

CONCLUSIONS

A PCRR was associated with significantly higher confidence in US report interpretation, but was underpowered to demonstrate increased accuracy in identifying US findings. These findings justify future studies of PCRRs for hydronephrosis care.

Usefulness of Ultrasonography and Cortical Transit Time to Differentiate Nonobstructive From Obstructive Dilatation in the Management of Prenatally Detected Pelvic Ureteric Junction Like Obstruction

OBJECTIVE

To differentiate a nonobstructive dilatation from an obstructive dilatation in prenatally detected presumed pelvi-ureteric junction obstruction so that intervention can be planned before irreversible damage can occur to the renal unit.

MATERIALS AND METHODS

From January 2012 to December 2016, all patients with prenatally detected or asymptomatic incidentally detected presumed pelvi-ureteric junction obstruction were evaluated by ultrasonography and renogram. The anteroposterior diameter of the renal pelvis was measured in supine and prone position. Presence of calyceal dilatation in prone position was noted. They were categorized into obstructed, nonobstructed, and equivocal groups based on sonography findings. The differential renal function and the cortical transit time (CTT) was calculated and compared with the sonography groups.

RESULTS

Of the 98 patients, 72 were in the obstructed, 18 were in the nonobstructed, and 8 were in the equivocal category. All except 1 in the nonobstructed category had a function of >40% with CTT of <3 minutes. Seventy patients in the obstructed category had a CTT of >3 minutes, whereas 61 had function <40% on initial evaluation. Eleven patients in the obstructed category with an initial function of >40% had CTT of >3 minutes. All of them showed increasing hydronephrosis and deterioration of function during follow-up, necessitating pyeloplasty. All patients in the equivocal group had function >40% and CTT <3 minutes.

CONCLUSION

Ultrasonography along with CTT can help to differentiate nonobstructive from obstructive dilatation.

Ultrasonography of hydronephrosis in the newborn: a practical review

Widespread use of fetal ultrasonography is accompanied by more frequent detection of antenatal hydronephrosis. Therefore, sonographic evaluation of neonates with a history of antenatal hydronephrosis is becoming more widespread. As an initial postnatal non-invasive imaging modality, ultrasonography is used to screen for persistence of hydronephrosis, determine the level and severity of obstruction, and contribute to appropriate diagnosis and treatment. This review aims to provide a practical overview of the sonographic evaluation of neonatal hydronephrosis and to describe the sonographic findings of conditions associated with hydronephrosis in the newborn.

Evaluation of Urinary Tract Dilation Classification System for Grading Postnatal Hydronephrosis

PURPOSE

We assessed the reliability and validity of the Urinary Tract Dilation classification system as a new grading system for postnatal hydronephrosis.

MATERIALS AND METHODS

We retrospectively reviewed charts of patients who presented with hydronephrosis from 2008 to 2013. We included patients diagnosed prenatally and those with hydronephrosis discovered incidentally during the first year of life. We excluded cases involving urinary tract infection, neurogenic bladder and chromosomal anomalies, those associated with extraurinary congenital malformations and those with followup of less than 24 months without resolution. Hydronephrosis was graded postnatally using the Society for Fetal Urology system, and then the management protocol was chosen. All units were regraded using the Urinary Tract Dilation classification system and compared to the Society for Fetal Urology system to assess reliability. Univariate and multivariate analyses were performed to assess the validity of the Urinary Tract Dilation classification system in predicting hydronephrosis resolution and surgical intervention.

RESULTS

A total of 490 patients (730 renal units) were eligible to participate. The Urinary Tract Dilation classification system was reliable in the assessment of hydronephrosis (parallel forms 0.92). Hydronephrosis resolved in 357 units (49%), and 86 units (12%) were managed by surgical intervention. The remainder of renal units demonstrated stable or improved hydronephrosis. Multivariate analysis revealed that the likelihood of surgical intervention was predicted independently by Urinary Tract Dilation classification system risk group, while Society for Fetal Urology grades were predictive of likelihood of resolution.

CONCLUSIONS

The Urinary Tract Dilation classification system is reliable for evaluation of postnatal hydronephrosis and is valid in predicting surgical intervention.

Predictors for the need of surgery in antenatally detected hydronephrosis due to UPJ obstruction--a prospective multivariate analysis

INTRODUCTION

Disagreement exists over the ability of different diagnostic tests to define obstruction, indications and timing of surgery and which patients will benefit from surgical intervention in antenatal hydronephrosis (ANH) due to ureteropelvic junction obstruction (UPJO). We try to find a way to predict which patients of ANH due to UPJO will eventually need surgery during conservative management.

MATERIAL AND METHODS

Prospective single centre study involving 122 renal units at a referral centre in India. Patients on conservative management were followed using a standard protocol and operated for pre-defined indications defining failure of conservative management. Patients who underwent surgery were compared with the non-operated group in terms of sex, side, baseline grade of hydronephrosis, maximum anterioposterior diameter on first postnatal ultrasound and differential renal function on first renal scan.

RESULTS

A total of 109 renal units qualified for conservative management. Of those, 23.9% required operative intervention during follow-up. Median time to failure of conservative management was 37 weeks. The median follow-up of non-operated cases was 54 months. Univariate analysis revealed that society of fetal urology (SFU) grade of hydronephrosis, anteroposterior diameter (APD), cortical thickness (CT), and pre-operative differential renal function (DRF) had a significant association with surgery (P < 0.05). Multivariate analysis revealed APD and pre-operative DRF as the only independent predictors for requiring surgery, while CT and initial SFU grade of hydronephrosis were not. Receiver operating curve analysis showed that an APD of 24.3 mm could predict the need for surgery, with a sensitivity of 73.1% and a specificity of 88.0%.

CONCLUSIONS

APD and DRF are the predictive factors for surgery. We stop short of recommending surgery only on the basis of APD. Instead we recommend that efforts be made to improve the specificity of this criterion, or by using APD in perspective with the differential renal function. We can reduce the burden of investigations in those with APD <24 mm while those with APD >24 mm can be more comprehensively monitored.

Should prenatal hydronephrosis that resolves before birth be followed postnatally? Analysis and comparison to persistent prenatal hydronephrosis

BACKGROUND

Prenatal ultrasonography has greatly enhanced detection of congenital genitourinary abnormalities. However, although persistent prenatal hydronephrosis (PPH) is typically imaged and followed postnatally, it remains unclear if prenatal hydronephrosis that resolves in utero (RPH) should be similarly managed. We determined postnatal abnormalities associated with RPH and compared these to those associated with PPH.

METHODS

We performed a retrospective review of all consecutive patients evaluated for prenatal hydronephrosis over 24 months. Patients were followed prenatally with serial ultrasounds and postnatally with ultrasonography and a voiding cystourethrogram.

RESULTS

Of the consecutive 165 patients enrolled in the study, 72 had RPH. The average prenatal anterior-posterior renal pelvis length was significantly longer in patients with PPH (5.5 mm) than in those with RPH (4.9 mm) (p = 0.01). Recurrent postnatal hydronephrosis occurred in 44% of patients with RPH, with eventual resolution in 34% of those affected. In comparison, 29% of PPH cases resolved postnatally. Mean time to resolution was statistically shorter for PPH (116 days) than for RPH (175 days) (p = 0.01). Seven PPH patients required surgery, while no RPH patients needed intervention (difference was statistically significant).

CONCLUSIONS

A significant number of RPH children had postnatal hydronephrosis. Despite a slower resolution time, no children with RPH required intervention. Although RPH may recur postnatally, the significantly lower chance of intervention being required suggests that these children may not require postnatal imaging.

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.

Prediction of the outcome of antenatally diagnosed hydronephrosis: a multivariable analysis

PURPOSE

The majority of cases of antenatal hydronephrosis (ANH) resolve postnatally. The purpose of this study was to determine independent predictors for resolution of ANH using a multivariable analysis model.

METHODS

A retrospective study was performed on 100 children (80 males and 20 females, 118 renal units) referred to a single pediatric urology clinic with the diagnosis of ANH. Patients with ultimately resolved ANH were compared to unresolved cases in a univariate analysis in terms of sex, laterality, severity of ANH using Society for Fetal Urology (SFU) grading, antero-posterior pelvic diameter (APD), parenchymal thickness, renographic differential function and development of clinical complications, followed by a Cox proportional hazard model for multivariable analysis.

RESULTS

Median follow up was 34 months (range 3-204). Hydronephrosis in 62 units resolved spontaneously and pyeloplasty was done in 29. The remaining 27 units had persistent uncomplicated hydronephrosis at last follow up. Multivariate analysis showed larger APD (hazard ratio 0.54; 95%CI 0.36-0.80) and SFU grade 4 (HR 0.34; 95%CI 0.13-0.90) to be associated with a significantly lower likelihood of resolution. The mean initial APD in resolved cases was 9.4mm as opposed to 29.0mm in cases requiring surgery.

CONCLUSION

Large initial APD has predictive value for surgical intervention. This model is helpful in counseling families about the potential outcomes of ANH.

Predictive value of decreased renal pelvis anteroposterior diameter in prone position for prenatally detected hydronephrosis

PURPOSE

It is important to differentiate between those cases of prenatally detected hydronephrosis that are significant and those that are likely to resolve spontaneously. We evaluated the anteroposterior pelvic diameter of the renal pelvis postnatally in the supine and prone positions, and determined whether the difference between these 2 positions helps predict the outcome of prenatally detected hydronephrosis.

MATERIALS AND METHODS

From May 2009 to June 2011, 38 infants with prenatally detected unilateral ureteropelvic junction type hydronephrosis were evaluated. The anteroposterior pelvic diameter was noted in the supine and prone positions. Functional evaluation was done by radionuclide renogram. Those with a split function of less than 40% underwent pyeloplasty. All other patients were followed by serial ultrasound examination.

RESULTS

Six infants had an anteroposterior pelvic diameter larger than 40 mm with no change in diameter in the supine vs prone positions. Seven of 16 infants with an anteroposterior pelvic diameter between 30 and 40 mm, and 11 of 15 infants with an anteroposterior pelvic diameter between 15 and 30 mm had a smaller anteroposterior pelvic diameter in the prone position. These infants had normal renal function, improvement in hydronephrosis and did not need pyeloplasty. All the infants with no change in anteroposterior pelvic diameter in either position had poorer renal function, necessitating pyeloplasty.

CONCLUSIONS

Those cases of prenatally detected ureteropelvic junction type of hydronephrosis in which the anteroposterior pelvic diameter is smaller in the prone position than in the supine position showed improvement in hydronephrosis, while those with no change in anteroposterior pelvic diameter had worsening of hydronephrosis and needed surgical intervention.

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

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

Management in children of mild postnatal renal dilatation but without vesicoureteral reflux

Infants with mild postnatal renal dilatation but without vesicoureteral reflux pose a challenge. For how long and in what way should they be followed? From May 1989 to December 2006, we prospectively followed 1,795 pregnancies in which the foetal renal pelvis measured 4 mm or greater. Voiding cystourethrography (VCUG) and renal ultrasound were performed on 1,315 infants at 6 weeks of age. Our study group comprised 208 (167 male) infants with normal VCUG findings who had a renal pelvis of 6-11 mm. We followed them for 1-17 years (mean 11 years). Medical and radiological records were reviewed to determine any urinary symptoms and final outcome. They underwent, on average, four further imaging tests. The renal dilatation had resolved by 24 months in approximately 70%. Urinary tract infection (UTI) developed in 16 (8%). Calyceal dilatation was more likely in those developing UTI (P=0.02). Twenty-two (10.6%) had a radiologically demonstrated urinary tract abnormality. Of the five who had renal scarring or severe obstruction, four became symptomatic. Most infants with mild postnatal renal dilatation can be investigated with only one further sonogram at 24 months of age. Mild postnatal renal dilatation is associated with subsequent UTI or renal tract abnormality in 18%. Severe renal abnormality occurred in 2.4%.

Postnatal follow-up of antenatal hydronephrosis: a health-care challenge

OBJECTIVE

To examine our experience with ANH and to determine the success of our postnatal follow-up program.

STUDY DESIGN

Charts of mothers and infants seen (2004 to 2008) at our Regional Perinatal Center were reviewed retrospectively. ANH was defined during the third trimester by anterior pelvic diameters as follows: mild 7 to 9, moderate 10 to 14 or severe >or=15 mm. Fetuses with multicystic dysplastic kidney (MCDK) were included.

RESULT

Screening of approximately 15 000 ultrasound (US) reports identified 268 fetuses with ANH. After prenatal US surveillance, 88 (33%) fetuses had resolved, while 180 (67%) required postnatal follow-up. These 180 fetuses were diagnosed with mild 38 (21%), moderate 83 (46%) and severe 19 (11%) ANH, uni or bilateral hydroureters 12 (7%), MCDK 19 (10%) and miscellaneous 9 (5%). Postnatal follow-up was successfully established for 75% of infants with hydroureters, 68% for those with MCDK and for 37% of infants with mild, 53% with moderate and 58% with severe ANH. Factors commonly known to influence compliance were not found more frequently among the 91 infants who were lost to follow-up. The only positive predictor for postnatal follow-up was a prenatal consultation with the pediatric urologist.

CONCLUSION

Our antepartum program for diagnosis of ANH is accessible and efficient; however, there was an unacceptably high number of infants lost to follow-up. The absence of traditional barriers for compliance highlights the need to explore new ways of improving postnatal follow-up of infants with ANH.

Antenatal renal pelvis dilatation: 2-year follow-up with DMSA scintigraphy

The aim of this study was to determine whether a postnatal ultrasound (US) can detect infants with antenatal renal pelvis dilatation (ARPD) who run a minimal risk of renal damage 2 years after birth. The study cohort consisted of 14,000 pregnant women who consecutively underwent routine US examinations during the second trimester. Subsequent examinations were performed on the basis of obstetrical indications. In total, 106 foetuses were diagnosed with ARPD > or =5 mm. Two postnatal US were performed on the newborns: on postpartum days 5-7 and during the third week of life. The findings were considered to be normal when the renal pelvis diameter (RPD) was < or = 7 mm and when there was no calyceal or ureteric dilatation or signs of renal dysplasia or other anomalies. Voiding cystourethrography (VCUG) was done at 6-8 weeks after birth. When the children reached 2 years of age, renal status was evaluated with DMSA scintigraphy or, if not possible, US. In 53 of the 103 children available for evaluation, the postnatal US findings were normal; 49 of the 53 children were also given a DMSA, and the results were normal in all cases. An US scan (all normal) only was performed in three children because the families refused a DMSA. One family refused any form of examination at the 2-year follow-up. Based on our results, we conclude that postnatal US can detect infants who do not require follow-up assessments of renal development.

Upper urinary tract dilatation: prenatal diagnosis, management and outcome

Upper urinary tract dilatation is one of the most common abnormalities detected on prenatal ultrasound scanning. It is commonly due to transient urine flow impairment (UFI) at the level of the pelvi-ureteric and vesico-ureteric junctions, which improves with time in most cases. It is usually in the neonatal period that the diagnosis is confirmed and during the first 18 months of life that the prognosis of the dilatation is defined.

Congenital urinary tract obstruction

Congenital urinary tract obstruction is a heterogenous condition with a varying natural history. Accurate diagnosis within the late-first and second trimesters allows for counselling of the parents and planning of multi-disciplinary care for the pregnancy and newborn. Antenatal investigations to predict postnatal renal function are of varying accuracy. However, some factors have been shown to be predictive of poor outcome in terms of renal function at birth and infancy. There is the possibility of in-utero intervention in these fetuses.

Is fetal anatomic assessment on follow-up antepartum sonograms clinically useful?

OBJECTIVE

The purpose of this study was to evaluate the clinical usefulness of a fetal anatomic survey on follow-up antepartum sonograms.

METHODS

A retrospective follow-up study was conducted at a low-risk maternity clinic from July 1, 2005, to June 30, 2006. Eligible women had at least 1 prior sonographic examination beyond 18 weeks' gestation with a complete and normal fetal anatomic assessment and at least 1 follow-up sonogram. Full fetal anatomic surveys were performed on all follow-up sonograms regardless of the indication. Neonatal charts were reviewed for those patients whose follow-up sonograms revealed unanticipated fetal anomalies. Neonatal intervention was defined as surgical or medical therapy or arranged subspecialty follow-up specifically for the suspected fetal anomaly.

RESULTS

Of a total of 4269 sonographic examinations performed, 437 (10.2%) were follow-up studies. Of these, 101 (23.1%) were excluded because the initial sonogram revealed a suspected fetal anomaly, and 42 (9.8%) were excluded for other reasons. Of the remaining 294 women, 21 (7.1%) had an unanticipated fetal anomaly, most often renal pyelectasis. Compared with follow-up sonography for other reasons, repeated sonography for fetal growth evaluation yielded a higher incidence of unexpected fetal anomalies: 15 (12.3%) of 122 versus 6 (3.5%) of 172 (P = .01). When compared with the neonates in the nongrowth indications group, those neonates whose mothers had sonographic examinations for fetal growth had a higher rate of neonatal interventions: 6 (40.0%) of 15 versus 0 (0%) of 6 (P = .04).

CONCLUSIONS

A fetal anatomic survey on follow-up sonograms may identify unanticipated fetal anomalies, especially when the indication is for fetal growth.

Postnatal management of isolated mild pelvic dilatation detected in antenatal period

AIM

Mild antenatal renal pelvic dilatation (ARPD) revealed by prenatal ultrasound (US) raises the question whether or not screening for vesicoureteral reflux (VUR) is mandatory. The aim of our study was to suggest guidelines for postnatal management of infants with mild ARPD defined as an antero-posterior (AP) dilatation >5 and <10 mm.

METHOD

Therefore we assessed the value of postnatal US at day 30 to predict VUR, the incidence of VUR at day 30 and the rate of spontaneous resolution at 1 year. Two hundred (200) infants with ARPD were included and had renal US and voiding cystourethrography (VCUG) at day 30. If VUR was present, VCUG was repeated 1 year later.

RESULTS

Incidence of VUR was 10% (20/200) at day 30 after birth and only 3% (6/200) 1 year later. VUR at day 30 was twice as frequent in children with postnatal dilatation (11%) than in nondilated kidneys (6%).

CONCLUSIONS

Considering the low incidence of VUR at 1 year, screening for VUR in mild ARDP seems not to be justified. However follow-up by US to detect increase in dilatation and clinical monitoring for signs of urinary infection is required.

Mild pyelectasis diagnosed by prenatal ultrasound is not a predictor of urinary tract morbidity in childhood

OBJECTIVES

To determine whether children with prenatally diagnosed mild pyelectasis have more urinary tract morbidity during childhood than children without this finding.

METHODS

Case-control study in children with pyelectasis (anteroposterior diameter of the fetal renal pelvis of 5-10 mm). A validated questionnaire was sent to the parents of 208 cases and 416 matched controls.

RESULTS

The questionnaire was returned by 146 cases and 250 controls. There was a male predominance in the case group (p = < 0.0001). There was no difference in voiding habits or in prevalence of urinary tract infections (UTI). The prevalence of UTI was high: 11.6% in cases and 10.0% in controls. The only difference was a higher prevalence of constipation in the case group (p = 0.003). Postnatally, 41 children had an ultrasound examination and 16 were referred to a paediatrician or urologist: 3 had persisting pyelectasis, 3 had a recurrent UTI and 1 required surgery (a pyeloplasty). Four of the controls were referred to a paediatrician or urologist: 3 had recurrent UTI and 1 had urinary incontinence.

CONCLUSION

Children with a mild fetal pyelectasis do not have more urinary tract morbidity during childhood than children without this finding. Therefore, there seems to be no need for additional investigation after birth.

Antenatal renal pelvic dilatation; the long-term outlook

AIM

The purpose of this study was twofold: first to provide data for more accurate counselling of parents with regard to prognosis, and second, to ensure that by following a policy of selective micturating cystourethography (MCUG), significant pathology is not missed, in particular vesicoureteric reflux (VUR). (MCUG is only undertaken if the renal pelvic diameter (RPD) is >/= 10 mm or if there is calyceal or ureteric dilatation.)

MATERIAL AND METHODS

Data were collected prospectively over a 6-year period. Pre and postnatal imaging findings were collected for all infants in whom a RPD of >/= 5 mm was identified at any gestational age. The imaging records of all patients were reviewed in 2005 for evidence of pathology detected after re-presentation with symptoms. The age range at review varied from 2-8 years.

RESULTS

Complete data were available in 527 infants. The risk of significant pathology was related to the degree of antenatal renal pelvic dilatation varying from 6% for a RPD of 5 mm at 20 weeks gestation to 38% at 10 mm. At 28-33 weeks gestation the risk varied from 5% at 5mm to 15% at 10 mm. Subsequent imaging record review revealed only one patient with grade II VUR in the study population not picked up by our selective MCUG policy.

CONCLUSION

The present study provides prognostic information that can be given to parents both antenatally and postnatally, and reassurance that a selective MCUG policy is appropriate.

Magnetic Resonance Urographic Parameters for Predicting the Need for Pyeloplasty in Infants With Prenatally Diagnosed Severe Hydronephrosis

PURPOSE

Treatment in infants with prenatally diagnosed, severe hydronephrosis remains controversial. We measured anatomical parameters using magnetic resonance urography to create a pelvic index ratio, which we correlated with outcome to assess its value.

MATERIALS AND METHODS

We reviewed 35 cases of prenatally diagnosed severe hydronephrosis, including grade III in 19 and grade IV in 16. By 6 weeks after birth all patients had undergone repeat ultrasonography, diuretic renography and magnetic resonance urography. Magnetic resonance urography was used to measure the distance (D) from the bottom of the lowest renal calyx to the ureteropelvic junction and the total longitudinal length (L) of the caliceal system. The pelvic index ratio, defined as D/L, assesses the level at which the ureter inserts into the renal pelvis.

RESULTS

All cases were initially managed conservatively. Pyeloplasty was required in 16 kidneys (mean patient age +/- SD 7.5 +/- 3.9 months) because of deterioration in renal function. All patients were well at a mean followup of 3.8 years. The remaining 19 cases continued to be managed conservatively. By a mean of 5.4 years spontaneous resolution of prenatally diagnosed severe hydronephrosis had occurred in 7 of 19 cases, while 12 were downgraded to grades I-II. The mean pelvic index ratio in surgical cases was 0.26 +/- 0.13 and in nonsurgical cases it was 0.12 +/- 0.11, indicating that ureters inserted significantly higher in surgical cases (p = 0.0012). Of 9 kidneys with a pelvic index ratio of greater than 0.3 pyeloplasty was required in 8, while 10 of 12 with a pelvic index ratio of less than 0.1 were managed conservatively.

CONCLUSIONS

Pyeloplasty is likely to be required if the pelvic index ratio is greater than 0.3 and conservative management is likely to succeed if the ratio is less than 0.1. The pelvic index ratio can be calculated easily even in the neonatal period. It appears to be prognostic for pyeloplasty in cases of prenatally diagnosed, severe hydronephrosis.

The magnitude of fetal renal pelvic dilatation can identify obstructive postnatal hydronephrosis, and direct postnatal evaluation and management

PURPOSE

Up to 1% of prenatal ultrasounds will detect fetal renal pelvic dilatation. We sought to evaluate and determine whether fetal renal pelvic measurements may appropriately direct prenatal counseling and postnatal evaluation and management.

MATERIALS AND METHODS

We performed a retrospective analysis of prospectively collected measurements of anteroposterior renal pelvic dilatation obtained at a single fetal maternal medicine center between 1990 and 2003. Fetuses with renal pelvic dilatation 4 mm or greater at less than 33 weeks of gestation, or 7 mm or greater at more than 33 weeks of gestation were evaluated postnatally at a single pediatric urology center. Infants with renal pelvic dilatation were evaluated with ultrasound, voiding cystourethrograms and renal scintigraphy. Renal obstruction was the main outcome measure assessed. Obstruction was defined as the need for surgery and was not based on the renal scan drainage time. Indications for surgery included declining function and increasing hydronephrosis.

RESULTS

There were 257 neonates with prenatally detected renal pelvic dilatation. A mean maximum prenatal renal pelvic dilatation of 11.8 mm was seen in 195 patients with nonobstructive dilatation. In the 62 patients with obstruction there was a nearly 2-fold increase in the mean renal pelvic dilatation (22.3 mm), which was statistically significant. Receiver operating characteristic analysis revealed that when 15 mm renal pelvic dilatation is used as a threshold it correctly discriminates obstruction in at least 80% of fetuses with a sensitivity of 73% and a specificity of 82%.

CONCLUSIONS

The magnitude of fetal renal pelvic dilatation is predictive of obstruction. Our results suggest that 15 mm renal pelvic dilatation represents a significant threshold. Receiver operating characteristic analysis provides a useful guide for prenatal counseling and may help to direct the postnatal evaluation.

Antenatal hydronephrosis as a predictor of postnatal outcome: a meta-analysis

OBJECTIVE

Antenatal hydronephrosis is diagnosed in 1% to 5% of all pregnancies; however, the antenatal and postnatal management of hydronephrosis varies widely. No previous studies define the risk of postnatal pathology in infants with antenatal hydronephrosis. Our objective was to review the current literature to determine whether the degree of antenatal hydronephrosis and related antenatal ultrasound findings are associated with postnatal outcome.

METHODS

We searched Medline (1966-2005), Embase (1991-2004), and the Cochrane Library databases for articles on antenatal hydronephrosis. We required studies to have subjects selected on the basis of documented measurements of antenatal hydronephrosis and followed to a postnatal diagnosis. We excluded case reports, review articles, and editorials. Two independent investigators extracted data.

RESULTS

We screened 1645 citations, of which 17 studies met inclusion criteria. We created a data set of 1308 subjects. The risk of any postnatal pathology per degree of antenatal hydronephrosis was 11.9% for mild, 45.1% for moderate, and 88.3% for severe. There was a significant increase in risk per increasing degree of hydronephrosis. The risk of vesicoureteral reflux was similar for all degrees of antenatal hydronephrosis.

CONCLUSIONS

The findings of this meta-analysis can potentially be used for prenatal counseling and may alter current postnatal management of children with antenatal hydronephrosis. Overall, children with any degree of antenatal hydronephrosis are at greater risk of postnatal pathology as compared with the normal population. Moderate and severe antenatal hydronephrosis have a significant risk of postnatal pathology, indicating that comprehensive postnatal diagnostic management should be performed. Mild antenatal hydronephrosis may carry a risk for postnatal pathology, but additional prospective studies are needed to determine the optimal management of these children. A well-defined prospective analysis is needed to further define the risk of pathology and the appropriate management protocols.

Postnatal management of infants with antenatally detected hydronephrosis

With the increasing use of antenatal sonography, fetal hydronephrosis has been reported more frequently. Because of the lack of consensus regarding treatment of these infants, the postnatal approach toward fetal renal pelvis enlargement remains controversial. The aim of this prospective study is to demonstrate the postnatal investigation, treatment, and outcome of infants with prenatally diagnosed hydronephrosis. Infants whose antenatal ultrasound scan showed a fetal renal pelvis of 5 mm or greater were investigated postnatally using ultrasound (US) and voiding cystourethrography. When indicated, isotope studies and intravenous urograms were also performed. We followed prospectively neonates with antenatally diagnosed hydronephrosis and recommended management guidelines on the basis of our findings. In 156 neonates (193 kidney units) that were found to have hydronephrosis, the average gestational age at which the diagnosis was made was 32.94+/-5.10 weeks. The mean duration of postnatal follow-up was 26.3+/-13.56 months (range 3-60 months). The mean APPD of the fetal renal pelvis was 10.35+/-3.24 mm (5-9 mm in 84 kidneys, 10-14 mm in 96 kidneys and > or =15 mm in 13 kidneys). Of the 193 kidney units, 145 units were found to be pathological. The most common detected underlying abnormalities were ureteropelvic junction obstruction (in 91 kidneys; 62.7%) and vesicoureteral reflux (in 24 kidneys; 16.6%). Postnatally, 23 (45%) of 51 patients whose first US was normal were diagnosed postnatally as having urinary tract abnormality. There was a negative correlation between APPD and the rate of spontaneous resolution and positive correlation between APPD and the rate of surgery (P<0.01). In conclusion, because it is not possible to determine an upper limit of normal for the antenatal renal pelvis, any baby with AH should not be considered clinically insignificant. Infants with antenatal renal pelvis measurements > or =5 mm should be investigated postnatally. A normal postnatal ultrasound scan does not preclude the presence of urinary tract abnormality.

Mild renal pyelectasis in the second trimester: determination of cut-off levels for postnatal referral

OBJECTIVE

To establish guidelines for postnatal referral of fetuses presenting with mild pyelectasis in the second trimester of pregnancy.

METHODS

In a retrospective study, 87 fetuses with a renal pelvis anteroposterior (RPAP) diameter of > or = 4 mm and < or = 10 mm before 28 weeks of gestation were included. All patients had a third-trimester scan and fetuses with an RPAP diameter of > or = 10 mm at that stage were referred for postnatal assessment. The family practitioner of all infants with an RPAP of < 10 mm in the third trimester was contacted for follow-up information. The RPAP diameter most predictive of renal pathology was determined with receiver-operating characteristics (ROC) curve analysis for both the first and second scans.

RESULTS

In 36 of 87 infants, 49 abnormal kidneys were diagnosed. Seven infants required surgery on eight renal tracts. The ROC curves of the first scan, second scan and differences between scans resulted in an area under the curve of 0.60, 0.87 and 0.85, respectively. The sensitivities and specificities for a cut-off level of 8, 9 and 10 mm at the second scan were 80%, 71% and 61% and 79%, 90% and 93%, respectively. At a cut-off level of 10 mm, only cases of insignificant minimal dilatation and a case of vesicoureteric reflux (VUR) requiring surgery were not detected.

CONCLUSION

After establishing a diagnosis of mild pyelectasis before 28 weeks, a second scan is mandatory to determine which infants need postnatal evaluation. A cut-off level of 8 mm has a low specificity but includes most cases of pathology. A cut-off level of 10 mm detects most significant pathology; however, VUR may not be detected.

Insights into the pathogenesis and natural history of fetuses with renal pelvis dilatation

Fetal renal pelvis dilatation is a frequent abnormality that has been observed in 4.5% of pregnancies. The majority of these cases have a tendency to resolve during infancy. Nevertheless, fetal renal pelvis dilatation may be due to significant structural abnormalities such as pelvi-ureteric junction stenosis or vesico-ureteral reflux that may adversely affect renal function or cause urinary infection or sepsis. This review article aims to summarize the data regarding fetal renal pelvis dilatation and to analyze controversial attitudes in the light of the various lines of practice, and to present rational antenatal and postnatal investigation strategy.

Prenatal diagnosis and management of mild fetal pyelectasis: implications for neonatal outcome and follow-up

OBJECTIVES

To describe the natural history of pyelectasis from its detection in the second trimester to delivery, its capability to predict renal pathology and whether prenatal development of pelvic dilatation is correlated to its postnatal evolution.

STUDY DESIGN

A retrospective analysis involving 375 fetuses with a complete urological follow-up. Prenatal ultrasound was correlated with the results of postnatal investigation and frequency of postnatal surgery was established.

RESULTS

Two-hundred and eighty cases underwent at least two examinations before birth. 73.1% were male fetuses. 57.4% had a bilateral pyelectasis. Prenatal evolution of pelvic dilatation was the following:18.6% of the cases normalized, in 34.6% of the cases the dilatation reduced but did not disappear, in 30.7% it remained unchanged, while it worsened in 16.4%. One case from the first group, three cases from the second, seven cases from the third and 11 cases from the fourth needed surgical treatment. 1.9, 7.2, 18.6, 23.9% of cases respectively worsened after birth in the four groups (trend: P=0.001).

CONCLUSIONS

Prenatal diagnosis of pyelectasis improves the outcome of these children due to a surgical approach that avoids renal damage. There is a good correlation between prenatal evolution and postnatal outcome, although a postnatal follow-up is opportune in those cases that normalized before birth.

[Neonatal pelvic ectasia: long-term outcome and association with ureterovesical anomalies]

OBJECTIVE

To analyze the outcome of neonatal pelvic ectasia (PE) and the association between this entity and vesicoureteral reflux and/or other urinary tract abnormalities.

PATIENTS AND METHODS

We performed a retrospective study of 255 children (205 boys, 50 girls) with an ultrasonographic diagnosis of PE in the first month of life. The initial ultrasonographic examination was indicated by urinary tract infection in 30 neonates, abnormalities in the prenatal ultrasonographic examination in 150 and by other reasons in 75. Pelvic ectasia was classified in four stages according to anteroposterior pelvic diameter: I < 1 cm, II 1-1.5 cm, III 1.6-2 cm, and IV > 2 cm.

RESULTS

Pelvic ectasia was bilateral in 153 children (60 %) and unilateral in 102 (left side in 81.4 % and right side in 18.6 %). Stage I was found in 75.49 %, stage II in 20.34 %, stage III in 3.9 % and stage IV in 0.24 %. The mean follow-up was 32.6 +/- 25.2 months. At the end of the first year, the results of renal ultrasound were normal in 70.2 % of left-sided PE and in 55.9 % of right-sided PE, but 46 patients (18 %) showed worsening of PE between the first and second ultrasound scans. Voiding cystourethrography was performed in 79.6 % of the children and some abnormalities were found in 50 (24.6 %): urethral dilatations in two patients and vesicoureteral reflux in 48. No correlation was found between vesicoureteral reflux and the degree of ectasia (74 % had an anteroposterior diameter of < or = 1 cm). Urinary tract infection was present in 24.3 % of the children and 13 required surgery (eight pyeloplasties, four urethral reimplantations and two resections of type III urethral valves).

CONCLUSIONS

Neonatal PE was more prevalent in boys (4:1) and was more frequently located on the left side in both sexes. Associated vesicourethral reflux was found in 23.64 % with no correlation between the degree of dilation and the presence or degree of reflux. Consequently, cystourethrography should be performed in any child with pelvic ectasia, regardless of stage, side or sex.

Diagnostic accuracy of fetal renal pelvis anteroposterior diameter as a predictor of uropathy: a prospective study

OBJECTIVE

The purpose of this study was to assess the accuracy of prenatal ultrasound measurement of anteroposterior renal pelvis diameter (APD) to discriminate between significant uropathy and idiopathic renal pelvis dilatation.

METHODS

One-hundred-and-three neonates who were found to have fetal renal pelvis dilatation, defined as presence of an APD > or = 5 mm, underwent systematic investigation for uropathies and were prospectively followed. An ultrasound scan was performed after the first week of postnatal life and all infants underwent a voiding cystourethrogram. Neonates with an APD larger than 10 mm underwent renal scintigraphy. Ultrasound scans, clinical examination and laboratory reviews were scheduled at 6-month intervals. Receiver-operating characteristics (ROC) curves were constructed to determine the best cut-offs for APD to identify renal units with significant uropathy as well as those requiring surgical intervention. Significant uropathy was defined as the presence of well-established urinary tract abnormalities or when there was abnormal renal scintigraphy.

RESULTS

The estimated area under the curve for APD was 0.900 (95% CI, 0.841-0.942) indicating excellent power to discriminate between idiopathic pelvis dilatation and significant uropathy. The sensitivity and specificity for the 7.5 mm cut-off point were 97.9% and 40.6%, respectively. To identify infants who required surgical intervention, the calculated area under the curve was 0.953 (95% CI, 0.908-0.980).

CONCLUSION

Our results suggest that measurement of APD is an excellent test to identify fetuses with significant uropathy, as well as those requiring postnatal intervention.

Diagnostic accuracy of postnatal renal pelvic diameter as a predictor of uropathy: a prospective study

BACKGROUND

There is a necessity to standardize postnatal ultrasonographic markers predictive of significant uropathies. The purpose of this study was to assess the accuracy of anteroposterior renal pelvic diameter (APD) on postnatal ultrasound to discriminate between significant uropathy and idiopathic renal pelvic dilatation.

MATERIALS AND METHODS

Neonates ( n=110) who were found to have isolated fetal renal pelvic dilatation underwent systematic investigation and were prospectively followed up. A US scan was performed after the 1st week of life, and all infants underwent voiding cystourethrography. Neonates with an APD larger than 10 mm were examined with renal scintigraphy. Receiver-operating characteristic (ROC) plots were constructed to determine the best cutoffs for APD to identify renal units with significant uropathy as well as those requiring surgical intervention.

RESULTS

The area under the curve (AUC) estimated by the ROC curve was 0.921 (95% CI=0.869-0.957), indicating excellent discriminant power between nonsignificant pelvis dilatation and significant uropathy. A cutoff of 10 mm for APD showed the best accuracy for identifying infants with a significant uropathy (sensitivity, 90.4%; specificity, 91%). To identify infants who required surgical intervention, the calculated AUC was 0.976 (95% CI=0.940-0.993). A cutoff of 15 mm showed the best diagnostic performance for identifying the renal units requiring pyeloplasty (sensitivity, 100%; specificity, 92.5%).

CONCLUSION

Our results suggest that postnatal APD is an excellent test for identifying fetuses with significant uropathy, as well as those requiring postnatal intervention.

Antenatal diagnosis of surgically correctable anomalies: effects of repeated consultations on parental anxiety

OBJECTIVE

To assess whether or not a correlation exists between antenatal consultations and parental anxiety.

STUDY DESIGN

In total, 31 couples undergoing prenatal consultation after a diagnosis of a surgically correctable anomaly were asked to fill in a questionnaire (Spielberger State-Trait Anxiety Inventory) measuring anxiety levels (AL) both after the first consultation and at birth. Prenatal counselling was done by a perinatal team including paediatric surgeon, obstetrician, and psychologist.

RESULTS

Malformations were: eight diaphragmatic hernias, 10 intestinal atresias, four abdominal masses, nine abdominal wall defects. Each fetus was subsequently followed up at regular intervals from diagnosis to birth. AL at birth were then compared with the number of antenatal consultations. A negative correlation (r=-0.688, p<0.001) was found between the number of consultations and the level of anxiety at birth. Patients having at least two consultations had significantly lower anxiety levels at birth.

CONCLUSION

Irrespective of the type of malformation, there is evidence that having more than one antenatal consultation may significantly reduce AL at birth. Therefore, early antenatal diagnosis should be encouraged in order to increase as much as possible chances of repeated consultations for the prospective parents.

Antenatal hydronephrosis: evaluation and outcome

We present a comprehensive and current review of the etiology, evaluation, treatment, and outcome of antenatal hydronephrosis. When a diagnosis of antenatal hydronephrosis is made, many questions regarding pregnancy, prenatal care, intervention, and what may be expected after birth are raised. Debate and controversy exist on the diagnosis and subsequent evaluation and management of the child with antenatal hydronephrosis. A review of the literature and our own experience with antenatal hydronephrosis are presented in order to guide the physician who is caring for mother and child.

Prenatal diagnosis: does it alter outcome?

The prenatal detection of urinary tract anomalies is changing paediatric practice but in many areas the impact on clinical outcome remains difficult to quantify. However it is already apparent that termination of pregnancy has reduced the numbers of infants with lethal pulmonary hypoplasia and renal dysplasia who would previously have been liveborn but destined to succumb as neonates. Similarly, referrals of major non lethal abnormalities such as bladder exstrophy are declining as parents increasingly opt for termination. Fetuses at greatest risk of early onset postnatal renal failure can now be identified with considerable accuracy on prenatal ultrasound. Termination, prompted by quality of life considerations, could result in reduced numbers of infants and young children requiring end stage renal failure treatment in the first few years of life. Pre natal detection of anomalies such as PUJ obstruction and reflux undoubtedly provides an opportunity to avert functional deterioration and minimise urinary infection. But the proportion of children who genuinely benefit has proved difficult to assess. The prenatal detection of mild dilatation is of doubtful benefit in all but a minority of cases. Clinically significant underlying pathology is rare yet this common prenatal finding often generates disproportionate parental anxiety.

Prenatal hydronephrosis

Prenatal hydronephrosis is diagnosed with an incidence of 1:100 to 1:500 maternal-fetal ultrasonographic studies. Although ultrasonography accurately describes dilation of the renal collecting system, it cannot define mechanical obstruction, a functional characteristic. The purpose of prenatal screening has changed from simple detection of hydronephrosis to selection for specific diagnosis-based management. The natural history of prenatal hydronephrosis is difficult to determine, and therefore physicians who take care of the fetus and infant are challenged with the following question: when does dilation of the renal collecting system indicate that serious pathology (ongoing renal deterioration) exists? The diagnosis of prenatal hydronephrosis, indications for and timing of prenatal intervention, and recommendations for treating children with a history of prenatal hydronephrosis are included in this review.