Prenatal diagnosis and management of hydronephrosis

ACR Appropriateness Criteria® Antenatal Hydronephrosis-Infant

Antenatal hydronephrosis is the most frequent urinary tract anomaly detected on prenatal ultrasonography. It occurs approximately twice as often in males as in females. Most antenatal hydronephrosis is transient with little long-term significance, and few children with antenatal hydronephrosis will have significant obstruction, develop symptoms or complications, and require surgery. Some children will be diagnosed with more serious conditions, such as posterior urethral valves. Early detection of obstructive uropathy is necessary to mitigate the potential morbidity from loss of renal function. Imaging is an integral part of screening, diagnosis, and monitoring of children with antenatal hydronephrosis. Optimal timing and appropriate use of imaging can reduce the incidence of late diagnoses and prevent renal scarring and other complications. In general, follow-up neonatal ultrasound is recommended for all cases of antenatal hydronephrosis, while further imaging, including voiding cystourethrography and nuclear scintigraphy, is recommended for moderate or severe cases, or when renal parenchymal or bladder wall abnormalities are suspected. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Prenatal Diagnosis and Findings in Ureteropelvic Junction Type Hydronephrosis

The widespread use of obstetric ultrasonography has increased the detection rate of antenatal hydronephrosis. Although most cases of antenatal hydronephrosis are transient, one third persists and becomes clinically important. Ultrasound has made differential diagnosis possible to some extent. Ureteropelvic junction type hydronephrosis (UPJHN) is one of the most common cause of persistent fetal hydronephrosis and occurs three times more in male fetuses. It is usually sporadic and unilateral. However, when bilateral kidneys are involved and presents with severe hydronephrosis, the prognosis may be poor. Typical ultrasound findings of UPJHN is hydronephrosis without hydroureter. The size and appearance of the fetal bladder is usually normal without thickening of the bladder wall. Several grading systems are developed and increasingly being used to define the severity of prenatal hydronephrosis and provides much more information about prediction of postnatal renal prognosis. If fetal urinary tract dilation is detected; laterality, severity of hydronephrosis, echogenicity of the kidneys, presence of ureter dilation should be assessed. Bladder volume and emptying, sex of the fetus, amniotic fluid volume, and presence of associated malformations should be evaluated. Particularly the ultrasonographic signs of renal dysplasia, such as increased renal parenchymal echogenicity, thinning of the renal cortex, the presence of cortical cysts, and co-existing oligohydramnios should be noticed. Unfortunately, there is no reliable predictor of renal function in UPJHN cases. Unilateral hydronephrosis cases suggesting UPJHN are mostly followed up conservatively. However, the cases with bilateral involvement are still difficult to manage. Timing of delivery is also controversial.

Early pyeloplasty versus conservative management of severe ureteropelvic junction obstruction in asymptomatic infants

BACKGROUND

Ureteric-pelvic junction obstruction (UPJO) is the most common cause of antenatal and neonatal hydronephrosis and its management remains controversial. While conservative management is advocated for all, this strategy puts a quarter of these patients at risk for possibly irreversible renal damage.

AIM

In this study, we compare functional and anatomic outcomes in newborns and infants less than 1 year of age with high-grade unilateral UPJO, following early surgical pyeloplasty (ESP) versus conservative management (CM).

MATERIALS AND METHODS

This was a single center prospective interventional study. Infants referred to our tertiary care pediatric surgery clinic between September 2016 and September 2018 with UPJO were considered. To be included patients must have been less than 1 year old, lack of clinical symptoms, suffer from severe hydronephrosis as defined by Society for Fetal Urology (SFU) grades 3 or 4, and have affected kidney Split Renal Function (SRF) above 40%. Patients with bilateral disease, structural anomalies, or an abnormal voiding cystourethrogram (VCUG) were excluded. Anatomical and functional outcomes were measured and compared at 6 and 12 months.

RESULTS

Fifty-six patients were assigned to receive either ESP (n = 28) or CM (n = 28). At 6 months Cortical thickness, polar length, and SFU indices were significantly lower in the ESP group, while none of the outcomes were significantly different between the two groups at 12 months. Despite the two groups not being different at 12 months regarding differential renal function (DRF), there was a significant decrease of function in the CM group compared to baseline.

CONCLUSION

When considering treatment options for infants with high-grade UPJO, it appears that ESP hastens improvement of anatomic and functional indices, while CM may lead to a significant deterioration in renal function.

Prenatal Diagnosis of Megacystitis and Hydronephrosis in an Equine Fetus: How Transabdominal Ultrasonography Can Help to Diagnose Fetal Abnormalities

Premature udder development constitutes an alarm signal in pregnant mares. The objective of this clinical case report is to highlight the importance of transabdominal ultrasound examination of the fetus in these cases and to report a unique case of prenatal diagnosis of obstructive uropathy based on the observation of severe fetal hydronephrosis and megacystitis in utero. A 4-year-old French chaser primiparous mare was referred for evaluation of premature udder development during the ninth month of pregnancy. The mare had clinical signs within normal limits, a developed and sensitive udder with secretions, and no vulvar discharge. Transrectal examination revealed the presence of an immobile fetus. Combined uteroplacental thickness was within normal limits. Transabdominal ultrasound revealed a single live fetus in posterior presentation with several abdominal abnormalities. Unilateral hydronephrosis and megacystitis lead to a hypothetical diagnosis of fetal multiple urinary tract malformation with outflow obstruction. Treatment was discontinued and the mare was monitored. Abortion occurred spontaneously a week later. Postmortem examination revealed a ruptured bladder of abnormally large dimensions and a severely distended left kidney without parenchyma (filled with free urine) and lack of permeability in the left ureter and urethra. Postmortem diagnosis was consistent with our prenatal ultrasonographic diagnosis. Even though described during human pregnancy with various etiologies and severity, prenatal diagnosis of fetal hydronephrosis and megacystitis has not been reported in equine veterinary medicine before. These malformations need to be characterized more precisely in the future. This case highlights the importance of transabdominal ultrasonography to detect equine fetal abnormalities.

Study of the renal Parenchymal volume during the human fetal period

Objective:

To evaluate the renal parenchymal area in human fetuses, providing a descriptive analysis on the renal area development by demographic factors during the second gestational trimester.

Material and Methods:

We analyzed 84 fetuses (44 males and 40 females), for a total of 168 renal units evaluated in terms of longitudinal length, superior pole width, inferior pole width and thickness. Renal volume was calculated by ellipsoid formula. After renal pelvis dissection, length and width were evaluated; as pelvis is free of urine, we considered thickness as 1mm. Renal pelvis volume was also calculated by ellipsoid formula. Renal parenchymal area was assessed by excluding the volume of the renal pelvis from the total renal volume. We performed the statistical analysis by simple linear regression assessing the association between the variables analyzed with the fetal age.

Results:

Gestational age ranged from 12 to 23 weeks post conception. Mean renal parenchymal area of the right kidney was 666.22mm³ (45.86 to 2375.35mm³) and for the left kidney was 606.76mm3 (68.63 to 2402.57mm³). No statistical difference was observed between the sides (p-value = 0.3456) or genders (p-value = 0.07429). Linear regression between renal parenchymal volume and gestational age was positive for right kidney (y = 133.74x-1479.94 / r² = 0.4009) and left kidney (y = 149.53x-1761.59 / r² = 0.4591).

Conclusions:

The linear regression analysis indicated that renal parenchymal area correlated significantly and positively with fetal age, weight and crown-rump length with no statistical differences between gender or laterality. These growth curves provide a reference for functional volume of the kidney during fetal period.

Is it Always Necessary to Treat an Asymptomatic Hydronephrosis Due to Ureteropelvic Junction Obstruction?

The postnatal treatment of asymptomatic unilateral hydronephrosis due to ureteropelvic junction obstruction remains controversial, and the timing of and indications for surgical intervention are continuously debated. There is no consensus on the best follow-up during expectant management. The various modalities and parameters have been discussed along with their pros and cons and an attempt has been made to clear up the controversies.

Determination of the Need for Surgical Intervention in Infants Diagnosed with Fetal Hydronephrosis in China

Background

Hydronephrosis is a common congenital condition. The detection of fetal hydronephrosis by ultrasound presents a treatment dilemma. This study aims to examine postnatal follow-up and treatment for hydronephrosis diagnosed prenatally.

Material/Methods

This was a retrospective study of 210 infants with hydronephrosis diagnosed at the Qilu Hospital (Shangdong, China) between January 2005 and January 2013. The patient cohort was divided into four groups based on prenatal ultrasound examinations using the Society for Fetal Urology (SFU) classification system. Data on follow-up investigations and treatment methods were extracted from the charts and analyzed.

Results

Patients with SFU grade 1, 2, and 3 hydronephrosis (n=125, n=74, and n=11, respectively) were followed for two years. In all, 2.4%, 18.9%, and 90.9% of patients with SFU grade 1, 2, and 3 hydronephrosis, respectively, underwent surgery. SFU grade 3 (HR=9.23, 95% CI: 1.43–59.74, p=0.02), APD (HR=2.81, 95% CI: 1.11–7.10, p=0.03), and parenchymal thickness (HR=0.42, 95% CI: 0.24–0.71, p=0.001) were independently associated with the occurrence of surgery. For anterioposterior diameter, using a cut-off point of 1.1, the area under the curve was 0.86, Youden index was 0.556, sensitivity was 70.4%, and specificity was 85.3%. For parenchymal thickness, using a cut-off point of 5, AUC was 0.79, Youden index was 0.478, sensitivity was 74.1%, and specificity was 73.8%.

Conclusions

Patients with SFU grade 2 hydronephrosis require long-term follow-up. Surgery and close postsurgical observation may be necessary for patients with SFU grade 3 and 4 hydronephrosis. An initial B-mode ultrasound screening at 7–10 days after birth may help make an optimal diagnosis and treatment selection.

Postnatal Evaluation and Outcome of Prenatal Hydronephrosis

BACKGROUND

Prenatal hydronephrosis (PNH) is dilation in urinary collecting system and is the most frequent neonatal urinary tract abnormality with an incidence of 1% to 5% of all pregnancies. PNH is defined as anteroposterior diameter (APD) of renal pelvis ≥ 4 mm at gestational age (GA) of < 33 weeks and APD ≥ 7 mm at GA of ≥ 33 weeks to 2 months after birth. All patients need to be evaluated after birth by postnatal renal ultrasonography (US). In the vast majority of cases, watchful waiting is the only thing to do; others need medical or surgical therapy.

OBJECTIVES

There is a direct relationship between APD of renal pelvis and outcome of PNH. Therefore we were to find the best cutoff point APD of renal pelvis which leads to surgical outcome.

PATIENTS AND METHODS

In this retrospective cohort study we followed 200 patients 1 to 60 days old with diagnosis of PNH based on before or after birth ultrasonography; as a prenatal or postnatal detected, respectively. These patients were referred to the nephrology clinic in Zahedan Iran during 2011 to 2013. The first step of investigation was a postnatal renal US, by the same expert radiologist and classifying the patients into 3 groups; normal, mild/moderate and severe. The second step was to perform voiding cystourethrogram (VCUG) for mild/moderate to severe cases at 4 - 6 weeks of life. Tc-diethylene triamine-pentaacetic acid (DTPA) was the last step and for those with normal VCUG who did not show improvement in follow-up examination, US to evaluate obstruction and renal function. Finally all patients with mild/moderate to severe PNH received conservative therapy and surgery was preserved only for progressive cases, obstruction or renal function ≤35%. All patients' data and radiologic information was recorded in separate data forms, and then analyzed by SPSS (version 22).

RESULTS

200 screened PNH patients with male to female ratio 3.5:1 underwent first postnatal control US, of whom 65% had normal, 18% mild/moderate and 17% severe hydronephrosis. 167 patients had VCUG of whom 20.82% with VUR. 112 patients performed DTPA with following results: 50 patients had obstruction and 62 patients showed no obstructive finding. Finally 54% of 200 patients recovered by conservative therapy, 12.5% by surgery and remaining improved without any surgical intervention.

CONCLUSIONS

The best cutoff point of anteroposterior renal pelvis diameter that led to surgery was 15 mm, with sensitivity 88% and specificity 74%.

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.

A New Grading System for the Management of Antenatal Hydronephrosis

BACKGROUND AND OBJECTIVES

Standard clinical assessments do not predict surgical intervention in patients with a moderate degree of upper tract hydronephrosis. This study investigated whether combined measures of renal calyceal dilation and anteroposterior diameter (APD) of the renal pelvis at the first postnatal ultrasound better predict surgical intervention beyond standard assessments of the APD or Society of Fetal Urology (SFU) grading system.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A retrospective cohort of 348 children with antenatal hydronephrosis followed from 2003 to 2013 were studied. Using Cox regression, the risk for surgery by APD, SFU, and combined grading on the basis of the first postnatal ultrasound was calculated. The predictive capability of each grading system for surgery was determined by calculating the positive likelihood ratio (LR+).

RESULTS

The combination of APD≥6-9 mm and diffuse caliectasis had a hazard ratio (HR) of 19.5 (95% confidence interval [95% CI], 3.94 to 96.9) versus 0.59 (95% CI, 0.05 to 6.53) for APD≥6-9 mm alone and a similar risk of 8.9 for SFU grade 3 (95% CI, 3.84 to 20.9). The combination of APD≥9-15 mm and diffuse caliectasis had an HR of 18.7 (95% CI, 4.36 to 80.4) versus 1.75 (95% CI, 0.29 to 10.5) for APD≥9-15 mm alone. The LR+ for surgery for diffuse caliectasis and APD≥6-9 mm was higher than for APD≥6-9 mm alone (HR=2.62; 95% CI, 0.87 to 7.94 versus HR=0.04; 95% CI, 0.01 to 0.32) and was higher for APD≥9-15 mm and diffuse caliectasis than APD≥9-15 mm alone (HR=2.0; 95% CI, 1.15 to 3.45 versus HR=0.14; 95% CI, 0.04 to 0.43). Both combined groups of moderate hydronephrosis (APD≥6-9 mm or ≥9-15 mm with diffuse caliectasis) had only slightly higher LR+ than SFU grade 3 (HR=1.89; 95% CI, 1.17 to 3.05).

CONCLUSIONS

These results suggest a grading system combining APD and diffuse caliectasis distinguishes those children with moderate degrees of upper tract hydronephrosis that are at higher risk of surgery.

Prognostic value of three-dimensional ultrasound for fetal hydronephrosis

The present study evaluated the prognostic value of three-dimensional ultrasound for fetal hydronephrosis. Pregnant females with fetal hydronephrosis were enrolled and a novel three-dimensional ultrasound indicator, renal parenchymal volume/kidney volume, was introduced to predict the postnatal prognosis of fetal hydronephrosis in comparison with commonly used ultrasound indicators. All ultrasound indicators of fetal hydronephrosis could predict whether postnatal surgery was required for fetal hydronephrosis; however, the predictive performance of renal parenchymal volume/kidney volume measurements as an individual indicator was the highest. In conclusion, ultrasound is important in predicting whether postnatal surgery is required for fetal hydronephrosis, and the three-dimensional ultrasound indicator renal parenchymal volume/kidney volume has a high predictive performance. Furthermore, the majority of cases of fetal hydronephrosis spontaneously regress subsequent to birth, and the regression time is closely associated with ultrasound indicators.

Diagnosis of 65 cases of ampullary renal pelvis after postnatal follow-up of 1,167 newborn infants with prenatally suspected hydronephrosis

The aim of the present study was to assess the morbidity of ampullary renal pelvis (ARP) and document its natural history in post-natal life. A total of 1,167 newborn infants with prenatally suspected hydronephrosis were retrospectively analyzed. Of these, 65 patients were diagnosed with ARP by computed tomography urography (CTU) and/or magnetic resonance urography (MRU). All cases were followed up with ultrasonogrophy at 1, 3, 6 and 12 months after birth, and one case was followed up for 5 years. Changes in the separation of the renal pelvis collection system were recorded. Children with ARP accounted for 5.57% of the total cases (65/1,167) followed-up. No lack of connection between the renal calyces and the renal pelvis was detected. The long-term follow-up revealed that the separation of the renal pelvis collection system did not tend to increase over time. In addition to imaging examinations, long-term follow-up observation is recommended for the accurate diagnosis of pediatric ARP, particularly for differentiation from hydronephrosis.

Urinary tract infection and vesicoureteral reflux in children with mild antenatal hydronephrosis

OBJECTIVE

The postnatal management of mild antenatal hydronephrosis (ANH) remains controversial. The purpose of this study was to evaluate the incidence of UTI and VUR in children with mild ANH in order to determine the necessity of antibiotic prophylaxis (ABP) and VCUG.

METHOD

The data of 1511 patients with various grades of ANH who were referred to Department of Urology, Boston Children's Hospital between January 1998 and January 2010 were reviewed and 760 patients who had mild ANH were identified. The inclusion criteria were: 1) A confirmed report of ANH or actual prenatal ultrasound (US) images. 2) Postnatal evaluation and management conducted at the hospital. 3) Persistent mild hydronephrosis on the first US done between two weeks and three months of age. 4) No other US findings such as ureteral dilatation, duplication anomalies or bladder abnormalities. 5) At least one three-month follow up. Univariate statistical analysis was performed using a Student's t test.

RESULTS

Of the 760 patients who were identified, 608 (80%) were males, and 225 (30%) had bilateral mild hydronephrosis. Of these, 475 patients (63%) underwent an initial screening VCUG. VUR was identified in 13 patients (1.7%) with grades varying from 1 to 5. At follow up, hydronephrosis resolved in 67% of the renal units and worsened in 3.3%. Among the 692 patients with available follow-up data, 23 (3.3%) had a documented UTI. Twelve of these children had an initial screening VCUG that was negative for VUR. Of these 12 patients, seven underwent a subsequent RNC with none having VUR; five of the 12 patients did not undergo a repeat evaluation for VUR (four had a UTI after the screening VCUG and one had an afebrile UTI). Eleven of the 23 children with mild ANH did not have an initial screening VCUG, and all underwent a subsequent VCUG/RNC. Only two children were then found to have VUR Grade 4-5.

CONCLUSION

The incidence of UTI and VUR in children with mild ANH is low. Consequently, routine VCUG screening for VUR and the use of long-term ABP is not necessary for all patients with asymptomatic mild AHN. Evaluation for VUR in children with mild ANH should be reserved for those who subsequently present with a UTI.

Prenatal diagnosis of foetuses with congenital abnormalities and duplication of the MECP2 region

MECP2 duplication results in a well-recognised syndrome in 100% of affected male children; this syndrome is characterised by severe neurodevelopmental disabilities and recurrent infections. However, no sonographic findings have been reported for affected foetuses, and prenatal molecular diagnosis has not been possible for this disease due to lack of prenatal clinical presentation. In this study, we identified a small duplication comprising the MECP2 and L1CAM genes in the Xq28 region in a patient from a family with severe X-linked mental retardation and in a prenatal foetus with brain structural abnormalities. Using high-resolution chromosome microarray analysis (CMA) to screen 108 foetuses with congenital structural abnormalities, we identified additional three foetuses with the MECP2 duplication. Our study indicates that ventriculomegaly, hydrocephalus, agenesis of the corpus callosum, choroid plexus cysts, foetal growth restriction and hydronephrosis might be common ultrasound findings in prenatal foetuses with the MECP2 duplication and provides the first set of prenatal cases with MECP2 duplication, the ultrasonographic phenotype described in these patients will help to recognise the foetuses with possible MECP2 duplication and prompt the appropriate molecular testing.

Efficacy of prenatal ultrasonography in diagnosing urogenital developmental anomalies in newborns

BACKGROUND

Showing a prevalence rate of 0.5-0.8%, urogenital malformations discovered in newborns is regarded relatively common. The aim of this study is to examine the efficacy of ultrasound diagnostics in detecting developmental disorders in the urogenital system.

METHODS

We have processed the prenatal sonographic and postnatal clinical details of 175 urogenital abnormalities in 140 newborns delivered with urogenital malformation according to EUROCAT recommendations over a 5-year period between 2006 and 2010. The patients were divided into three groups; Group 1: prenatal sonography and postnatal examinations yielded fully identical results. Group 2: postnatally detected urogenital changes were partially discovered in prenatal investigations. Group 3: prenatal sonography failed to detect the urogenital malformation identified in postnatal examinations. Urogenital changes representing part of certain multiple disorders associated with chromosomal aberration were investigated separately.

RESULTS

Prenatal sonographic diagnosis and postnatal results completely coincided in 45%, i.e. 63/140 of cases in newborns delivered with urogenital developmental disorders. In 34/140 cases (24%), discovery was partial, while in 43/140 patients (31%), no urogenital malformation was detected prenatally. No associated malformations were observed in 108 cases, in 57 of which (53%), the results of prenatal ultrasonography and postnatal examinations showed complete coincidence. Prenatally, urogenital changes were found in 11 patients (10%), whereas no urogenital disorders were diagnosed in 40 cases (37%) by investigations prior to birth. Urogenital disorders were found to represent part of multiple malformations in a total of 28 cases as follows: prenatal diagnosis of urogenital malformation and the findings of postnatal examinations completely coincided in three patients (11%), partial coincidence was found in 22 newborns (79%) and in another three patients (11%), the disorder was not detected prenatally. In four newborns, chromosomal aberration was associated with the urogenital disorder; 45,X karyotype was detected in two patients, trisomy 9 and trisomy 18 were found in one case each.

CONCLUSION

In approximately half of the cases, postnatally diagnosed abnormalities coincided with the prenatally discovered fetal urogenital developmental disorders. The results have confirmed that ultrasonography plays an important role in diagnosing urogenital malformations but it fails to detect all of the urogenital developmental abnormalities.

Clinical importance of pyelocalyceal dilation diagnosed by postnatal ultrasonographic screening of the urinary tract

Background

Ultrasonographic (US) screening of the urinary tract (UT) in infants was used to determine if there is a connection between the frequency of pyelocaliceal dilation (PCD) in asymptomatic infants with normal antenatal US screening and occurrence of congenital anomalies of kidney and urinary tract (CAKUT) and urinary tract infections (UTI).

Material/Methods

US screening of the UT was performed on 1000 healthy infants, 7 days to 6 months old. Two subgroups of kidneys were described: subgroup 1 contained kidneys with anterior posterior pelvic diameter (APPD) of 5–9.9 mm, and subgroup 2 with APPD over 10 mm. US examinations and methods for detection of UTI and CAKUT were used.

Results

PCD was found in 74 infants (7.4%): 1.9% of infants had CAKUT, and 8.4% had UTI. In subgroup 1, CAKUT was found in 4 (6.3%) and UTI in 9 (14.3%) infants. In subgroup 2, CAKUT was found in 6 (54.5%), and UTI in 4 (36.4%) infants.

Conclusions

Mild PCD significantly increases the risk for CAKUT but not for UTI. Moderate to severe PCD significantly increases risk for both CAKUT and UTI. The postnatal US screening of UT is recommended for improved detection of PCD and associated CAKUT. Indirectly, postnatal US screening of UT can help in detecting people at risk for UTI in the first year of life, and therefore help prevent possible kidney damage.

Variations in management of mild prenatal hydronephrosis among maternal-fetal medicine obstetricians, and pediatric urologists and radiologists

PURPOSE

There are no current guidelines for diagnosing and managing mild prenatal hydronephrosis. Variations in physician approach make it difficult to analyze outcomes and establish optimal management. We determined the variability of diagnostic approach and management regarding prenatal hydronephrosis among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists.

MATERIALS AND METHODS

Online surveys were sent to mailing lists for national societies for each specialty. Participants were surveyed regarding criteria for diagnosing mild prenatal hydronephrosis and recommendations for postnatal management, including use of antibiotic prophylaxis, followup scheduling and type of followup imaging.

RESULTS

A total of 308 maternal-fetal medicine obstetricians, 126 pediatric urologists and 112 pediatric radiologists responded. Pediatric urologists and radiologists were divided between Society for Fetal Urology criteria and use of anteroposterior pelvic diameter for diagnosis, while maternal-fetal medicine obstetricians preferred using the latter. For postnatal evaluation radiologists preferred using personal criteria, while urologists preferred using anteroposterior pelvic diameter or Society for Fetal Urology grading system. There was wide variation in the use of antibiotic prophylaxis among pediatric urologists. Regarding the use of voiding cystourethrography/radionuclide cystography in patients with prenatal hydronephrosis, neither urologists nor radiologists were consistent in their recommendations. Finally, there was no agreement on length of followup for mild prenatal hydronephrosis.

CONCLUSIONS

We observed a lack of uniformity regarding grading criteria in diagnosing hydronephrosis prenatally and postnatally among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists. There was also a lack of agreement on the management of mild intermittent prenatal hydronephrosis, resulting in these cases being managed inconsistently. A unified set of guidelines for diagnosis, evaluation and management of mild intermittent prenatal hydronephrosis would allow more effective evaluation of outcomes.

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.

Ultrasound score: a new method to differentiate fetal physiological and pathological hydronephrosis

OBJECTIVE

To determine whether the prenatal ultrasound (US) score can effectively differentiate fetal physiological and pathological hydronephrosis.

STUDY DESIGN

158 fetuses (198 kidneys) with hydronephrosis (PAPD>or=10mm) were diagnosed by prenatal US in the third trimester. We measured and recorded three US parameters: renal pelvic anterior posterior diameter (PAPD), renal parenchyma thickness and pelvicaliceal morphology. They were graded with a score from 0 to 3 on the basis of severity of hydronephrosis, and the total US score of each kidney was obtained. According to the postnatal US and clinical diagnosis and management, all the cases were divided into two groups: physiological and pathological hydronephrosis. Using receiver operating characteristic curves analysis, we researched whether the US score was more accurate than each parameter and which was the best cut-off value for differential diagnosis of physiological and pathological hydronephrosis.

RESULTS

Of all the 198 hydronephrosis, 139 (70.20%) were physiological and 59 (29.80%) were pathological confirmed postnatally. Area under the curve of US score was 0.982, which was significantly larger than that of each parameter (P<0.05). The higher the score, the higher the possibility of pathological hydronephrosis was. Score 6 was the best cut-off value: the sensitivity, specificity, positive predictive value, negative predictive value, consistency rate and Youden's index were 89.83%, 94.24%, 86.89%, 95.62%, 92.93% and 0.8407, respectively.

CONCLUSION

Prenatal US score is easy to obtain by measuring some data of the kidney and can effectively differentiate fetal physiological and pathological hydronephrosis. It can also be used as a new quantitative method to evaluate the prognosis of fetal hydronephrosis so as to provide reference for prenatal intervention and more accurate information for the family of the fetus.

Fetal pyelectasis as predictor of decreased differential renal function

PURPOSE

A decreased percent of differential function is a common indication for infant pyeloplasty but there is no recognized fetal ultrasound parameter to predict this deficit. We determined whether there is a correlation between fetal pyelectasis and the newborn percent differential function that may enhance prenatal counseling and guide postnatal evaluation.

MATERIALS AND METHODS

Our database was queried for fetal and newborn measures with fetal pyelectasis on ultrasound and the percent of differential function on renal scintigraphy. Fetal pyelectasis data were stratified by estimated gestational age and the percent of differential function. The affected cohort was defined as having 35% or less differential function and the unaffected cohort was defined as having greater than 35%. The Wilcoxon 2-sample test was used for statistical analysis with logistic regression to generate estimated probability models of a decreased percent of differential function vs mm fetal pyelectasis.

RESULTS

A total of 831 cases had fetal and newborn ultrasound data available with a total of 229 renal scans identified. Of the 229 cases 36 (16%) had 35% or less differential function on scintigraphy. At estimated gestational age 33 weeks or less the affected cohort had 8 mm greater pyelectasis than the unaffected cohort (OR 1.2, p <0.0001). At estimated gestational age greater than 33 weeks the affected cohort had 4 mm greater pyelectasis than the unaffected cohort (OR 1.07, p <0.07). Subgroup analysis before 33 weeks of estimated gestational age showed similar significance (OR >1, p <or=0.001).

CONCLUSIONS

Approximately 16% of all fetuses with pyelectasis have 35% or less differential function as newborns, including 36% identified by pyelectasis greater than 10 mm at estimated gestational age 20 to 24 weeks. Fetal pyelectasis greater than 10 mm at estimated gestational age 20 to 24 weeks and greater than 16 mm at greater than 33 weeks is associated with 35% or less differential function in the newborn.

[Postnatal investigation and outcome of isolated fetal renal pelvis dilatation]

The purpose of this study was to evaluate the prognosis of fetal renal pelvis dilatation in relation to the degree of prenatal dilatation and the postnatal ultrasonography assessment. Based on these results, an algorithm is proposed for the choice of postnatal investigations and follow-up in children with fetal renal pelvis dilatation.

MATERIAL AND METHODS

The study was conducted prospectively among 10,677 newborns in Avignon over a nearly 5-year period. Infants with an anteroposterior pelvic diameter (APPD) 5mm or greater in the second trimester were enrolled with a threshold for the normal renal pelvis dimensions increasing with advancing gestation. Prenatal ultrasound was correlated with the results of postnatal investigation and frequency of surgical uropathy was established.

RESULTS

Pyelectasis was found in 1% of pregnancies and among 100 infants whose cases were followed, 23 (23%) had uropathies (seven isolated pelviureteric junction obstruction [PUJ], nine isolated vesicoureteral reflux [VUR], three VUR+PUJ, two duplicity, one obstructive megaureter, and one multicystic dysplastic kidney). The largest group of fetuses (66/100) had minor fetal pyelectasis of less than 10mm: in this group, 90% of the infants had no uropathy and there was no surgery. Six of 34 (17%) in the moderate (APPD> or =10 and<15mm) and severe (APPD> or =15mm) fetal pyelectasis groups required surgery, especially those with progressive PUJ obstructions. When postnatal ultrasound was normal in 64 infants (64%), there were only three mild or moderate (grades I-III), asymptomatic, and spontaneously resolving VUR. When pyelectasis was isolated and 10mm< or =APPD<15mm, cystourethrography was normal in 70% of the cases and only four cases of spontaneously resolving VUR were found. Among 23 infants with uropathies, six of 23 required surgery (26%), especially PUJ stenosis (5/6) with APPD greater than 15mm. In the total population of fetal pyelectasis, postnatal ultrasound predicted renal abnormalities with a sensitivity of 87% and a negative predictive value of 95%.

CONCLUSION

Normal neonatal ultrasound rarely coexists with significant abnormal findings and there seems to be no need for additional investigations when postnatal echography is normal. Cystourethrography can be delayed when pyelectasis is isolated with 10mm< or =APPD<15mm. Isolated and uninfected cases of VUR do not require surgery and all mild and moderate cases of VUR spontaneously resolved. All PUJ stenoses with APPD greater than 15mm required surgery.

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.

[Postnatal follow-up of children having antenatal hydronephrosis]

The application of antenatal ultrasound for the evaluation of congenital anomalies in early pregnancy has become a common practice. Hydronephrosis is the most common anomaly observed. Antenatal interventions are experimental and done in advanced centers. Though there are defined criteria of intervention, it is still not clear as to who will benefit. Most patients will have relatively benign course, however identification of those who will have potentially serious postnatal problems permits early intervention. This study gives recommendations for the postnatal examination and follow-up of the newborns having hydronephrosis diagnosed on antenatal ultrasound.

Hydronephrosis index: a better physiological reference in antenatal ultrasound for assessment of fetal hydronephrosis

OBJECTIVE

To establish a nomogram of fetal hydronephrosis index (HI) (anteroposterior diameter of renal pelvis divided by urinary bladder volume) at different gestational ages, to serve as a new reference for antenatal ultrasound examination, and to avoid overestimation of fetal hydronephrosis due to transient effect of a distended fetal bladder.

STUDY DESIGN

504 uncomplicated singleton pregnancies from 20 to 38 weeks' gestation were included. In each fetus, the maximum anteroposterior diameters of both renal pelves were measured on transverse view of fetal kidneys. Urinary bladder volume was calculated using the ovoid volume formula. HI was derived accordingly.

RESULTS

Values of HI vary significantly at different trimesters of pregnancy. HI was much higher (mean = 0.1543) from 20 to 27 weeks' gestation, and its value decreased significantly (mean = 0.0253) from 28 to 38 weeks' gestation (P < .05, independent-sample t test). As gestational age increased, HI decreased (R(2) = 0.5921).

CONCLUSIONS

HI is easy to be measured and can be used as a new physiological reference for assessment of fetal hydronephrosis by eliminating the confounding effect of a full fetal bladder. The change in values of HI throughout gestation supports the clinical importance of a nomogram for this new index.

Management of mild fetal pyelectasis: a comparative analysis

OBJECTIVE

The purpose of this study was to compare 2 protocols for the antenatal management of isolated mild fetal pyelectasis and perform a cost analysis.

METHODS

A retrospective analysis of unilateral and bilateral mild fetal pyelectasis followed at our institution from 2003 to 2006 was conducted. Fetuses with additional congenital anomalies or aneuploidy were excluded. Chi(2) analysis was used, and P < .05 was considered significant.

RESULTS

Two hundred forty-four cases were identified, of which the majority were male (75.4% versus 24.6%). Eighty-eight patients were reevaluated every 4 weeks (protocol 1). The remaining 156 patients were reevaluated once in the third trimester (protocol 2). The mean number of ultrasound examinations in protocol 1 was 3.24, at a cost of $1187, compared with protocol 2, at $798. Resolution occurred in 59%, stabilization in 29%, and progression in 12%. There were no cases of progression to severe pyelectasis or a need for in utero intervention in either group.

CONCLUSIONS

Mild fetal pyelectasis can be managed with 1 additional third-trimester ultrasound examination without a compromise in patient care. Average cost savings were $389 per patient for protocol 2, suggesting a benefit from this protocol over protocol 1.

Inheritance of pericentric inversion in chromosome 7 through the three progenies and a newborn with congenital hydronephrosis diagnosed prenatally by fetal urine sampling

OBJECTIVE

To report the inheritance of a pericentric inversion in chromosome 7 through the three progenies, congenital hydronephrosis, and recurrent miscarriages in an extended family.

DESIGN

Case report.

SETTING

Medical Faculty of Cukurova University in Turkey.

PATIENT(S)

Referred by obstetrics and gynecology clinic.

INTERVENTION(S)

Fetal urine and lymphocytic karyotype.

MAIN OUTCOME MEASURE(S)

Chromosomal analysis from fetal urine and peripheral blood lymphocytes were performed according to standard cytogenetic methods.

RESULT(S)

We assessed an extended family in which a large pericentric inversion in chromosome 7 is segregating; one of the three progenies with the karyotype 46,XY,inv(7)(p22;q22) was heterozygote for the inversion and presented with congenital hydronephrosis. His mother, mother's brother, grandfather, grandfather's brother, and his daughter were similar for the inversion.

CONCLUSION(S)

This case describes the further molecular characterization of these breakpoints on the short or long arm of chromosome 7(p22-q22). The inv(7) is also associated with fetal wastage and may be playing a role in the etiology of the family's miscarriages. These findings can be used in clinical genetics and may be an effective tool for reproductive guidance and genetic counseling.

Prenatal diagnosis of a rare form of congenital mid-ureteral stricture: a case report and literature revisited

Background

Congenital mid-ureteral stricture is a rare malformation of the ureter leading to prenatal and neonatal hydronephrosis. Site characterization of the narrowing is important to optimize the surgical approach to the newborn affected by hydronephrosis.

Case presentation

We report a female EM with a rare form of hydronephrosis, (i.e. mid-ureteral stricture) which was detected early during pregnancy by imaging techniques. During fetal life both conventional fetal Ultrasound and maternal Magnetic Resonance Imaging (MRI) were used to diagnose the obstruction. Magnetic Resonance pyelography and retrograde Ureteropyelography were performed after delivery and before surgical correction and confirmed the finding.

Furthermore, we revisited the literature using online MEDLINE and EMBASE databases. The literature reported only a few cases of prenatal diagnosis of early onset mid-ureteral stricture.

Conclusion

Mid-ureteral stricture is a rare cause of prenatal hydronephrosis. The diagnosis should not be delayed in order to apply the appropriate surgical approach. As a result, we showed the usefulness of fetal MRI and postnatal Magnetic Resonance pyelography, in the event that radionuclide renography with Tc-MAG3 was less informative, to allow the detection of the site of ureteral narrowing. Intrasurgical retrograde ureteropyelography confirmed these findings.