ANTENATAL HYDRONEPHROSIS: Fetal and Neonatal Management

doi:10.1016/S0031-3955(05)70558-7

Pediatric Clinics of North America

Volume 44, Issue 5, 1 October 1997, Pages 1299-1321

https://doi.org/10.1016/S0031-3955(05)70558-7 Get rights and content

In 1% of pregnancies, a significant structural fetal anomaly is detected by antenatal sonography.³⁸ Approximately half of these anomalies involve the central nervous system, whereas 20% are genitourinary, 15% are gastrointestinal and 8% are cardiopulmonary. Prenatal sonography allows the recognition of urologic abnormalities that otherwise would not be identified until later in life, when symptoms of pyelonephritis, stone disease, abdominal pain, or renal colic occur.²⁶ The probability of detecting a genitourinary abnormality depends on the experience and skill of the sonographer and usually is better late in gestation, when the fetus is larger and an anomaly is easier to image.³³

Most structural abnormalities of the urinary tract are characterized by hydronephrosis, which generally is assumed to be obstructive; however, often hydronephrosis is not caused by obstruction; examples include vesicoureteral reflux, multicystic kidney, and certain abnormalities of the ureteropelvic and ureterovesical junction.

An abnormality involving the genitourinary tract may be suspected in as many as 1 in 100 pregnancies, depending on the sonogram criteria.42, 56 The goal of management is to recognize and treat congenital anomalies that may adversely affect renal function or cause urinary infection or sepsis.

Section snippets

DEVELOPMENT OF KIDNEY AND RENAL FUNCTION

The kidney is derived from the ureteral bud and the metanephric blastema. During the fifth week of gestation, the ureteral bud arises from the mesonephric (wolffian) duct and penetrates the metanephric blastema, which is an area of undifferentiated mesenchyme on the nephrogenic ridge. The ureteral bud undergoes a series of approximately 15 generations of divisions, and by 20 weeks' gestation forms the entire collecting system, that is, the ureter, renal pelvis, calyces, papillary ducts, and

MANAGEMENT OF THE FETUS WITH ANTENATAL HYDRONEPHROSIS

When a fetus is identified with a suspected urinary tract abnormality, the goals of management include determining the differential diagnosis, assessment of associated anomalies, and determining the fetal and postnatal risk of the anomaly.

Hydronephrosis is recognized by demonstrating a dilated renal pelvis and calyces. The ureter and bladder may be dilated also. The likelihood of having a significant urinary tract abnormality is directly proportional to the severity of hydronephrosis.4, 42, 81

Management in the Nursery

At birth, the abdomen is inspected to detect the presence of a mass, which often is secondary to a multicystic kidney or UPJ obstruction. In male newborn infants with posterior urethral valves, often a walnut-shaped mass, representing the bladder, is palpable just superior to the pubic symphysis. Newborn infants also should be evaluated for anomalies involving other organ systems. Renal function should be monitored with serial serum creatinine levels, particularly in infants with bilateral

SUMMARY

As many as 1% of newborn infants have a prenatal diagnosis of hydronephrosis or significant renal pelvic dilation. Hydronephrosis often is caused by nonobstructive conditions. The likelihood of significant urologic pathology is directly related to the size of the fetal renal pelvis, and 90% with an anteroposterior diameter more than 2 cm need surgery or long-term urologic medical care. Following delivery, antibiotic prophylaxis should be administered and a renal sonogram and voiding

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Mothers’ perception of prenatal counseling following diagnosis of congenital anomalies of the urinary tract
2021, Archives de Pediatrie
Citation Excerpt :
Congenital abnormalities of the genitourinary tract are the most common sonographically identified malformations, accounting for 15–20% of all prenatally diagnosed congenital anomalies, and an overall incidence of 1–4 per 1000 pregnancies [1,2].
Congenital abnormalities of the genitourinary tract are the most common sonographically identified malformations. Although prenatal diagnosis seldom modifies perinatal management, it can cause significant anxiety in parents. We aimed to assess how parents perceived the prenatal counseling they had received in our institution.
Using a questionnaire, we evaluated by phone the mothers of 78 children diagnosed prenatally with urological tract anomalies between January 2018 and May 2019. Overall, mothers were satisfied and reassured by the prenatal counseling they received, although 19% of the mothers found the time from diagnosis to specialist consultation to be too long. Forty percent of the responders stated that the most important information they needed to hear during the specialist consultation was management and not diagnosis. Specialist counseling should focus on explaining postnatal management, should be offered as soon as possible, and should include practical aspects, especially concerning outpatient care.
Outcomes of urinary tract abnormalities diagnosed by the routine third trimester scan
2020, European Journal of Obstetrics and Gynecology and Reproductive Biology
The aim of this study is to determine the incidence of congenital abnormalities of the kidneys and urinary tract (CAKUT) detected for the first time in an unselected population undergoing a routine third trimester scan between 30–34 week’s gestation.
This was a retrospective analysis of 8562 routine third trimester ultrasound scans during which the fetal anatomy was evaluated, and, any structural abnormalities detected, recorded onto a fetal database which was subsequently analysed for CAKUT. All postnatal records of antenatally diagnosed CAKUT were obtained and analysed for diagnosis and management.
There were 26 cases of urological abnormalities detected for the first time in the third trimester. The most frequent abnormality was unilateral renal pelvis dilatation (73%). Postnatal ultrasound confirmed abnormalities in 19 (73%) newborns, with two (8%) resolving antenatally and four (15%) postnatally. The overall incidence of new CAKUT detected by the third trimester scan was 0.22% (19/8562) with a male to female ratio of 1:1.6. Four patients required surgery, two received cystoscopic injection of Deflux with circumcision, one received cystoscopic valve ablation and one patient received a staged hypospadias repair.
Routine third trimester scanning is already performed in many countries with proposed benefits primarily directed towards the monitoring of fetal growth and late pregnancy malpresentation. For healthcare systems that still utilize two routine scans, debate is ongoing as to the value of introducing a routine third trimester scan. The ability to detect additional and potentially missed CAKUT is a further benefit, which in isolation is likely of too small an impact to merit implementation. However, the combination of fetal structural assessment, growth velocity monitoring and fetal presentation evaluation presents a strong case for inclusion in an antenatal screening program. The findings of this study highlight the importance of a detailed fetal structural evaluation at each antenatal ultrasound scan.
Does the body weight influence the outcome in children treated with robotic pyeloplasty?
2020, Journal of Pediatric Urology
To investigate the influence of the body weight on peri- and postoperative outcome in a series of pediatric patients with a diagnosis of uretero–pelvic junction obstruction (UPJO) treated with robot-assisted laparoscopic pyeloplasty (RALP) at a single tertiary referral center.
In this study, outcomes of RALP in children divided according to the weight are evaluated.
Sixty-one consecutive patients treated with RALP from January 2016 to May 2019 were recorded retrospectively and divided according to their weight: group A < 15 kg, group B ≥ 15 kg and were included in this study. Eligible criteria for surgery were symptomatic UPJO, worsening of hydronephrosis, or obstructive pattern at renogram. Success criteria were the reduction of the hydronephrosis at imaging and the absence of flank pain. All procedures were performed by one expert robotic surgeon.
18 patients were included in group A (median weight 12 kg) and 43 patients in group B (median weight 33 kg). The median (IQR) operative was 95 (90–120) for group A compared to 90 (85–110) of control group. No significant difference has been found (P = 0.93). We registered one (5.6%) Clavien 3b complication (omental hernia after removal of the drainage requiring surgical correction) and two (4.7%) Clavien 2 complication in group B (urinary infections). No difference has been found in the length of hospital stay, length of catheterization, and duration of procedure between the groups (P > 0.05). At a median follow-up of 23 months (IQR 9–27 vs 9–33), the success rate was comparable between the two groups (94.4% vs 97.7%; P = 0.51). Relapse was recorded in one child per group and both required nephrostomy placement.
Our study tried to fill the gaps in the evidence on the feasibility of RALP in low-weight children reporting favorable peri-operative and long-term outcomes; however, this study shows some intrinsic limitations. The relatively small numbers of patients in the <15 kg may have underpowered the comparison with heavier patients. Moreover, only two patients were <10 kg so that no definitive conclusions on the safety and feasibility of RALP in this cohort of patients can be drawn.
RALP in children <15 kg was feasible and effective to treat UPJO with superimposable results to heavier counterparts. In our experience, the need for a different trocar placement and limited space in patients <15 kg did not affect peri-operative and functional outcomes.
Management of antenatally detected kidney malformations
2018, Early Human Development
Citation Excerpt :
Congenital abnormalities of the genitourinary tract are the most common sonographically identified malformations, with an incidence of approximately 1 to 4 per 1000 pregnancies [1]. These represent 15–20% of all prenatally diagnosed congenital anomalies [2]. The majority of cases have mild dilatation of the renal pelvis and a good outcome [3] but they tend to get aggregated into the ‘obstructive uropathy’ group with more severe bilateral pelvis and bladder dilatation secondary to lower urinary tract obstruction, typically posterior urethral valves in boys [4].
Congenital anomalies of the kidneys and the urinary tract (CAKUT) are one of the most common sonographically identified antenatal malformations. Dilatation of the renal pelvis accounts for the majority of cases, but this is usually mild rather than an indicator of obstructive uropathy. Other conditions such as small through large hyperechogenic and/or cystic kidneys present a significant diagnostic dilemma on routine scanning. Accurate diagnosis and prediction of prognosis is often not possible without a positive family history, although maintenance of adequate amniotic fluid is usually a good sign.
Both pre- and postnatal genetic screening is possible for multiple known CAKUT genes but less than a fifth of non-syndromic sporadic cases have detectable monogenic mutations with current technology. In utero management options are limited, with little evidence of benefit from shunting of obstructed systems or installation of artificial amniotic fluid. Often outcome hinges on associated cardiac, neurological or other abnormalities, particularly in syndromic cases. Hence, management centres on a careful assessment of all anomalies and planning for postnatal care.
Early delivery is rarely indicated since this exposes the baby to the risks of prematurity in addition to their underlying CAKUT. Parents value discussions with a multidisciplinary team including fetal medicine and paediatric nephrology or urology, with neonatologists to plan perinatal care and clinical geneticists for future risks of CAKUT.
What is the risk of urinary tract infection in children with antenatally presenting dilating vesico-ureteric reflux?
2015, Journal of Pediatric Urology
The incidence of recurrent urinary tract infection (UTI) in children with primary vesico-ureteric reflux (VUR) presenting symptomatically is well documented. The risk of UTI in asymptomatic primary VUR diagnosed on investigation of antenatal hydronephrosis (ANH) is less clear. Paradoxically, several previous studies have suggested a lower risk (1–25%). We ascertain the incidence of UTI amongst antenatally-presenting primary VUR and explore risk factors.
All patients <16 years managed for primary VUR between 1997 and 2013 were retrospectively reviewed. Patients were identified by searching ‘VUR, vesicoureteric reflux’ and ‘vesico’ in the clinical database. Sex, follow up, antibiotic prophylaxis, age at UTI, grade of VUR, radioisotope imaging findings (CRN-congenital reflux nephropathy, NRD-new renal defects), evidence of bladder dysfunction, surgical intervention and resolution were recorded. UTI diagnosis was based on positive urine culture with symptoms including fever. SPSS statistical package and Pearson’s Chi-squared test were used to explore significance.
Of 308 patients with primary VUR aged <16 years treated, 242 were diagnosed following presentation with UTI. The remaining 66 (21%) were initially asymptomatic, and VUR was diagnosed on investigation of ANH. All were given prophylaxis from birth. Six months to 16years (median 6years) follow-up was available for 54 (42 males, 12 females). All but two patients had grade III-V VUR (96%), bilaterally in 41 (76%). CRN was evident in 30 (56%; all male) and bladder dysfunction in 12 (22%; 10 males). Twenty-eight patients (52%) developed a UTI. The risk of UTI was 58% in girls, 33% in boys without CRN and 57% in boys with CRN (p = 0.17). Bladder dysfunction was a significant risk factor for UTI (p = 0.03). All 8 (15%; 7 males) with NRD had had a UTI. A single UTI appeared responsible for the majority of NRD (6/8; 75%). UTI occurred in 6/27 (22%) boys after circumcision compared to 17/25 (68%) prior/without circumcision (p < 0.05).
The incidence of UTI in VUR detected after presentation with ANH was 52%. CRN and bladder dysfunction were risk factors for developing a UTI. Circumcision appears to significantly reduce the risk of infection. Antenatal presentation of primary VUR does not carry a reduced risk of UTI. A single UTI, in half before the age of six months, seemed responsible for the majority of NRD. In boys, the highest risk of UTI is in the first few months of infancy, despite antibiotic prophylaxis, and other interventions, particularly circumcision, should therefore be considered as early as possible.
Obstructive Uropathy: Assessment of Renal Function in the Fetus
2012, Nephrology and Fluid/Electrolyte Physiology

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: Address reprint requests to Jack Elder, MD, Rainbow Babies and Children's Hospital, Division of Pediatric Urology, 2074 Abington Road, Cleveland, OH 44106

^*: From the Department of Urology and Pediatrics, Case Western Reserve University School of Medicine, and the Department of Pediatric Urology, Rainbow Babies & Children's Hospital, Cleveland, Ohio

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