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

Prenatal natural history of isolated fetal mild bilateral pyelectasis

OBJECTIVE

To analyze the prenatal outcomes in a cohort of fetuses with mild bilateral pyelectasis and determine whether performing serial ultrasounds is a good follow-up strategy.

METHODS

A prospective longitudinal study was conducted on 62 fetuses with mild bilateral pyelectasis. Fetal mild bilateral pyelectasis was considered when the renal pelvis measured (in millimeters) ≥5.0 to 10.0, ≥7.0 to 10.0, and ≥10.0 to 15 at ≤23 weeks 6 days, 24 to 31 weeks 6 days, and ≥32 weeks, respectively, with no uretero-calyceal dilatation. Ultrasounds were performed every 3 weeks to assess whether the mild bilateral pyelectasis regressed, remained unchanged (Group 1) or progressed (Group 2).

RESULTS

Group 1 consisted of 53 fetuses (85.4%), and progression was observed in 9 cases (Group 2, 14.6%). The initial renal pelvis diameter was significantly larger in fetuses with progression (p=0.028). Statistically significant differences in the renal pelvis diameter were also found at weeks 31 and 35 for both kidneys (p<0.05). The cases requiring intrauterine procedures or early delivery were not observed.

CONCLUSION

Fetal mild bilateral pyelectasis with no calyceal dilatation is a benign condition that can be managed in the postnatal period. The initial renal pelvis diameter and the diameter in week 31 or 35 were valuable parameters for identifying cases that would eventually need specific postnatal procedures.

Prevalence of defined ultrasound findings of unknown significance at the second trimester fetal anomaly scan and their association with adverse pregnancy outcomes: the Welsh study of mothers and babies population-based cohort

OBJECTIVE

The aim of this article was to estimate the population prevalence of seven defined ultrasound findings of uncertain significance ('markers') in the second trimester and the associated risk of adverse pregnancy outcomes.

METHOD

A prospective record-linked cohort study of 30 078 pregnant women who had second trimester anomaly scans between July 2008 and March 2011 in Wales was conducted.

RESULTS

The prevalence of markers ranged from 43.7 per 1000 singleton pregnancies for cardiac echogenic foci [95% confidence interval (CI): 38.8, 51.1] to 0.6 for mild-to-moderate ventriculomegaly (95% CI: 0.3, 1.0). Isolated echogenic bowel was associated with an increased risk of congenital anomalies [risk ratio (RR) 4.54, 95% CI: 2.12, 9.73] and preterm birth (RR 2.30, 95% CI: 1.08, 4.90). Isolated pelvicalyceal dilatation was associated with an increased risk of congenital anomalies (RR 3.82, 95% CI: 2.16, 6.77). Multiple markers were associated with an increased risk of congenital anomalies (RR 5.00, 95% CI: 1.35, 18.40) and preterm birth (RR 3.38, 95% CI 1.20, 9.53).

CONCLUSIONS

These data are useful for counselling families and developing clinical guidance and care pathways following the detection of markers in clinical practice, particularly the need for follow-up scans to monitor placental function and growth in pregnancies with isolated echogenic bowel, and further investigation for multiple markers. © 2015 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.

Postnatal management of antenatally detected hydronephrosis

With the increasing use of ultrasonography, congenital anomalies are often picked in utero. Antenatally detected hydronephrosis is amongst the most commonly detected abnormality. The management of this condition has raised considerable debate amongst clinicians dealing with it. This article is written with an idea to provide comprehensive information regarding the postnatal management of antenatally detected hydronephrosis. A detailed review of the current literature on this topic is provided. Also, guidelines have been given to facilitate the management of this condition.

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.

Natural history of fetal renal pyelectasis

OBJECTIVE

To follow the natural progression of fetal renal pyelectasis detected in the mid second trimester ultrasound in an unselected obstetric population.

STUDY DESIGN

Single-centered, retrospective study that included all level II ultrasounds done from Jan 2008 to Dec 2009. The initial level II ultrasound was done in the mid second trimester. The renal pyelectasis detected on the antenatal ultrasound (AUS) was classified as mild (5-7 mm), moderate (7.1-9 mm), or severe (>9.1 mm). Postnatal outcomes were classified as "Resolved", "Improving", or "Worsened".

RESULTS

Ninety-eight cases of fetal renal pyelectasis were detected. Sixteen patients were excluded. Of the remaining 82 cases of fetal pyelectasis, 32 (39%) were mild, 21 (25.6%) moderate, and 29 (35.4%) severe. In 74 (90.2%) infants, pyelectasis resolved, remained stable, or improved in the postnatal ultrasound. In eight (9.8%) infants, pyelectasis worsened.

CONCLUSION

Totally, 90.2% of pyelectasis detected on AUS resolved spontaneously, remained stable or improved. The magnitude of fetal renal pyelectasis did not correlate with postnatal outcome. All fetal renal pyelectasis ≥ 5 mm detected on the mid second trimester ultrasound should be followed antenatally. Those fetuses with persistent pyelectasis should be evaluated after birth and followed until resolution of pyelectasis or until a diagnosis is obtained.

Prenatal ultrasonography: implications for pediatric urology

Prenatal ultrasonography has become a critical and integral component of the obstetric care of women worldwide. As a result, a number of congenital anomalies are now routinely being detected prior to birth. Anomalies affecting the genitourinary system are among those most commonly detected, and thus pediatric urologists are increasingly being asked to provide parental counseling in such situations. However, much of the data needed to enhance these discussions and provide informed consent are absent from the literature. In this review, we hope to address the published literature describing the rapidly expanding role of ultrasound in prenatal care. More importantly, however, we hope to provide some insight into the manner in which prenatal ultrasound and subsequent urologic anomaly diagnosis has affected the practice of pediatric urology.

Prenatal diagnosis: what do we know of long-term outcomes?

Although prenatal diagnosis has been a prominent feature of Paediatric Urology for more than two decades the published literature has been largely characterized by studies reporting short to medium-term follow up. This deficiency is now being addressed by the growing availability of published and unpublished long-term outcome data for a range of prenatally detected anomalies. This review analyses the evidence on long-term outcomes which is provided by studies with mean or median follow- up exceeding 5 years, with particular emphasis on the small number of studies reporting follow -up at 10 years and beyond. The natural history and outcome of conservatively managed uropathies is considered in conjunction with an appraisal of evidence- based indications for surgical intervention. This review evaluates the relative benefits and drawbacks of prenatal diagnosis for children and their parents and also considers the impact of prenatal diagnosis on the delivery of Paediatric Urological services and specialist training.

[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.

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.

Prenatally diagnosed urinary tract abnormalities: long-term outcome

The long-term outcomes of prenatally detected uropathies are poorly documented. Limited data on fetal intervention show a possible reduction in early mortality from pulmonary hypoplasia, but no beneficial effect on long-term prognosis for renal function. Prenatally detected vesicoureteric reflux (VUR) is characterised by males with high-grade primary reflux, who are at long-term risk of renal impairment. Prenatal diagnosis and surgical intervention have contributed to a reduction in long-term morbidity in children with pelviureteric junction (PUJ) obstruction. By the same token, many children have almost certainly undergone unnecessary early pyeloplasty for an obstruction that would have resolved spontaneously. Multicystic dysplastic kidney (MCDK) carries a low (1%) risk of hypertension in childhood. The limited evidence on the long-term outcome of mild dilatation (pelvicaliectasis) indicates this is a largely innocent finding, which carries no increased risk of morbidity.

Vesico-ureteral reflux in children with prenatally detected hydronephrosis: a systematic review

OBJECTIVE

To investigate the value of prenatally detected hydronephrosis (PNH) as a prognostic factor for vesico-ureteral reflux (VUR).

METHODS

The MEDLINE database was searched for articles on PNH and VUR published between 1980 and 2004. A total of 18 studies were identified and reviewed for various aspects. Results were separated for primary and/or secondary VUR whenever possible, because of the different underlying pathogenic mechanisms.

RESULTS

There was considerable variation between the different studies with respect to methodology and study design. One of the main discrepancies was the way in which postnatal abnormalities were ascertained: by postnatal ultrasound, voiding cystourethrogram (VCUG) alone, or combined or sequential ultrasound and VCUG. Taking these limitations into account, the published data showed there to be a mean prevalence of 15% for postnatal primary VUR after PNH. Of all patients with PNH, 53% had no postnatal anomalies, whereas 29% had other anomalies, such as duplex collecting systems.

CONCLUSIONS

Of all infants with PNH, 15% had primary VUR proven postnatally and 53% had no other anomalies detected. We suggest a standardized protocol for future studies, to enable better comparison of follow-up protocols. Published by John Wiley & Sons, Ltd.