Diagnosis and treatment of fetal urinary tract abnormalities

The Frequencies of the Urinary Anomalies which were Detected in a Foetal Autopsy Study

AIM

The detection of foetal urinary abnormalities in the antenatal period will help in an adequate post natal management and it will also have a bearing on the decision of the termination of the pregnancy. The purpose of the present study was to detect urinary anomalies in the antenatal period by doing autopsies of the aborted foetuses.

SETTINGS AND DESIGN

A cross-sectional study.

METHODS AND MATERIAL

A total of 226 aborted foetuses were autopsied. The urinary anomalies which were related to the renal parenchyma, the pelvi-ureteral system and the urinary bladder were recorded. The associated anomalies of the other organ systems were also noted. The incidences of the different urinary anomalies among the aborted foetuses were calculated. The gestational ages at which the various anomalies were detected were also studied.

RESULTS

Twenty nine of the 226 fetuses were detected to have 34 urinary anomalies. Renal agenesis was the single most common anomaly. Overall, the anomalies which were related to the renal parenchyma accounted for 67.65 % of all the urinary anomalies, while the anomalies of the pelvi-ureteral system and the bladder constituted 20.59% of the detected urinary anomalies. The anomalies of the renal parenchyma (renal agenesis and horse-shoe and polycystic kidneys) were more frequently seen in the foetuses with a shorter gestational age as compared to the gestational ages of the foetuses which showed pelvi-ureteral anomalies. The cumulative incidence of the foetuses with urinary anomalies by 30 weeks of gestation was 12.83%.

CONCLUSIONS

A significant proportion of the aborted foetuses was detected to have urinary anomalies. An early antenatal detection of these and associated anomalies has significance, as this may help in an early postnatal diagnosis and management. The degree and the extent of the detected anomalies could also help in the decision making regarding the therapeutic abortions and the future pregnancies.

Late onset jaundice and urinary tract infection in neonates

OBJECTIVE

To determine the prevalence and the associated parameters of urinary tract infection (UTI) in infants with late onset jaundice.

METHODS

This prospective analytic study was conducted among 400 cases, selected by simple sampling from neonates with late onset jaundice admitted in two referral hospitals of Isfahan during a 9-month period. The information including the age, sex and feeding type, as well as the results of physical examination, treatment, radiology studies, etc were recorded. The etiology of jaundice was assessed by laboratory tests. Urine analysis and urine culture were performed for all subjects. XZ and t-test were used for analysis of the data in- SPSS software.

RESULTS

Of the 400 icteric neonates, 147 (36.8%) were female and 253 (63.3%) were male; 23 (5.8%) were diagnosed to have UTI, 5 cases (1.3%) had G6PD deficiency, 19 (4.8%) had dysmorphic red blood cell and 3(0.75%) had ABO or RH incompatibility. The relation between the type of feeding, circumcision and UTI was significant (P< 0.05). Of the 23 neonates with UTI,4 cases (17. 39%) were found to have urogenital abnormality.

CONCLUSION

UTI was found in 5.8% of infants with late onset jaundice. The study revealed significant association between breast feeding, circumcision and lower prevalence of UTI in icteric neonates. It is suggested that evaluation for UTI should be considered as a screening test in all cases of neonatal late onset jaundice.

May we go on with antibacterial prophylaxis for urinary tract infections?

Recurrent urinary tract infections (UTIs), with or without vesicoureteric reflux (VUR), are by far the most frequent reason for long-term antibacterial prophylaxis in infants and children today. However, the strategies of antibacterial prophylaxis for the prevention of recurrent urinary tract infection are no longer universally accepted. In infants and children at risk, the benefits of antibacterial prophylaxis definitively are not yet proven by evident data. To put antibacterial prophylaxis in its place, risk groups for recurrent symptomatic infections, ascending UTI and permanent renal damage have to be defined and the efficacy of prophylaxis in these groups has to be proved by prospective randomised studies. Nevertheless, until the results of these studies are available, antibacterial prophylaxis will remain one of the most frequently practised methods to protect risk patients from pyelonephritic damage and UTI recurrences.

Imaging studies after a first febrile urinary tract infection in young children

BACKGROUND

Guidelines from the American Academy of Pediatrics recommend obtaining a voiding cystourethrogram and a renal ultrasonogram for young children after a first urinary tract infection; renal scanning with technetium-99m-labeled dimercaptosuccinic acid has also been endorsed by other authorities. We investigated whether imaging studies altered management or improved outcomes in young children with a first febrile urinary tract infection.

METHODS

In a prospective trial involving 309 children (1 to 24 months old), an ultrasonogram and an initial renal scan were obtained within 72 hours after diagnosis, contrast voiding cystourethrography was performed one month later, and renal scanning was repeated six months later.

RESULTS

The ultrasonographic results were normal in 88 percent of the children (272 of 309); the identified abnormalities did not modify management. Acute pyelonephritis was diagnosed in 61 percent of the children (190 of 309). Thirty-nine percent of the children who underwent cystourethrography (117 of 302) had vesicoureteral reflux; 96 percent of these children (112 of 117) had grade I, II, or III vesicoureteral reflux. Repeated scans were obtained for 89 percent of the children (275 of 309); renal scarring was noted in 9.5 percent of these children (26 of 275).

CONCLUSIONS

An ultrasonogram performed at the time of acute illness is of limited value. A voiding cystourethrogram for the identification of reflux is useful only if antimicrobial prophylaxis is effective in reducing reinfections and renal scarring. Renal scans obtained at presentation identify children with acute pyelonephritis, and scans obtained six months later identify those with renal scarring. The routine performance of urinalysis, urine culture, or both during subsequent febrile illnesses in all children with a previous febrile urinary tract infection will probably obviate the need to obtain either early or late scans.

Renal Doppler ultrasonography in infants with hydronephrosis

The objective was to evaluate the importance of obstruction in unilateral hydronephrosis by using renal Doppler ultrasonography. A total of 19 infants were examined. It was revealed that patients of group with obstruction have in the affected kidney a higher mean resistive index [RI = 0.77 +/- 0.04] than in the healthy kidney [RI = 0.69 +/- 0.02] [p < 0.001]. In patients of group with nonobstructive dilatation this difference was not observed. In infants it is not possible to evaluate only absolute changes of the resistive index. It is much more useful to compare values of RI of both kidneys using the above indices. The determination of RI, RIR and delta RI can be helpful in distinguishing obstructed from non-obstructed hydronephrosis.

The natural history of neonatal vesicoureteral reflux associated with antenatal hydronephrosis

PURPOSE

In an attempt to evaluate the natural history of neonatal vesicoureteral reflux, patients with antenatal history of hydronephrosis and documented reflux in the first 30 days of life were analyzed.

MATERIALS AND METHODS

Between 1993 and 1998, 260 patients with a history of antenatal hydronephrosis were referred for evaluation. Of these patients 31 were diagnosed with unilateral or bilateral refluxing renal units (54 renal units). Patients were treated with a prospective plan of observational therapy and prophylactic antibiotics, and resolution rate was calculated in patients with adequate followup. Reflux grade was correlated with postnatal ultrasonographic findings, urinary tract infections and differential renal function. Outcome analysis of 34 high grade (III to V) refluxing renal units using the Kaplan-Meier survival curves was undertaken with the end point being complete resolution or improvement. Three patients with vesicostomy and 2 who underwent ureteral reimplantation were excluded from analysis.

RESULTS

Reflux was grade I in 5% (33% males), II in 15% (62% males), III in 32% (71% males), IV in 18% (90% males) and V in 30% (100% males) of the patients. Postnatal ultrasound findings correlated poorly with the presence and degree of vesicoureteral reflux. Of 17 patients followed for at least 14 months (average followup 20) there was complete resolution in 60% with grade III, 50% with grade IV and 28% with grade V reflux. Using the Kaplan-Meier estimate there was a 50% chance of improvement (decrease in reflux grade by at least 2 grades) in high grade reflux by age 16 months. Urinary tract infections developed in 8 patients (26%) while on antibiotics. Of 46 renal units in 23 patients evaluated with a renal scan before urinary tract infection, 12 had less than 35% function.

CONCLUSIONS

A normal postnatal ultrasound should not be a basis for excluding the use of cystography. Our Kaplan-Meier estimate shows that high grade reflux does improve and may resolve spontaneously. In addition, renal scarring may be seen with high and low grade reflux in the absence of urinary tract infection but high grade reflux is associated with a higher incidence of infection.

Does every patient with prenatal hydronephrosis need voiding cystourethrography?

PURPOSE

Prenatal ultrasound has allowed early identification of urinary tract abnormalities that may require urological followup or early intervention. While all children with prenatal hydronephrosis should undergo ultrasound within the first few weeks of life, we believe that there is a subset of postnatal hydronephrosis for which voiding cystourethrography can be avoided if careful observation is continued.

MATERIALS AND METHODS

For 5 years 175 infants with a history of prenatal hydronephrosis were evaluated by ultrasound. Of 60 infants with less than Society for Fetal Urology grade II unilateral or bilateral hydronephrosis 44 underwent voiding cystourethrography as part of the early evaluation and 16 were observed without voiding cystourethrography. Four infants for whom we would routinely obtain voiding cystourethrography were excluded from study due to severe prenatal hydronephrosis, renal duplication, hydroureter, ipsilateral small or echogenic kidney and grade II or higher hydronephrosis.

RESULTS

Voiding cystourethrography was positive in 6 of the 40 infants (15%) with less than grade II hydronephrosis. Of these cases 3 had grade III or higher vesicoureteral reflux and 1 with high grade reflux required reimplantation. None of the 16 patients followed without voiding cystourethrography has required further evaluation or intervention. In all patients with negative or no voiding cystourethrography parenchyma was preserved and hydronephrosis stabilized or resolved.

CONCLUSIONS

Prenatal and postnatal ultrasound in infants should be used to guide further urological evaluation. Among infants with less than grade II hydronephrosis postnatally 15% had reflux on voiding cystourethrography, which is significantly higher than that reported among normal children (approximately 1%). However, none of the 16 infants observed without voiding cystourethrography on short-term antibiotic prophylaxis had deleterious renal events with 6 months to 4.5 years of followup. Therefore, we question the actual significance of the reflux detected in the first cohort of infants. Voiding cystourethrography can provide a definitive answer. However, we also believe that it is not absolutely mandatory based on the outcome in the observed group. With careful counseling and followup most patients with less than grade II hydronephrosis can be observed without urological sequela.

Does every patient with prenatal hydronephrosis need voiding cystourethrography?

PURPOSE

Prenatal ultrasound has allowed early identification of urinary tract abnormalities that may require urological followup or early intervention. While all children with prenatal hydronephrosis should undergo ultrasound within the first few weeks of life, we believe that there is a subset of postnatal hydronephrosis for which voiding cystourethrography can be avoided if careful observation is continued.

MATERIALS AND METHODS

For 5 years 175 infants with a history of prenatal hydronephrosis were evaluated by ultrasound. Of 60 infants with less than Society for Fetal Urology grade II unilateral or bilateral hydronephrosis 44 underwent voiding cystourethrography as part of the early evaluation and 16 were observed without voiding cystourethrography. Four infants for whom we would routinely obtain voiding cystourethrography were excluded from study due to severe prenatal hydronephrosis, renal duplication, hydroureter, ipsilateral small or echogenic kidney and grade II or higher hydronephrosis.

RESULTS

Voiding cystourethrography was positive in 6 of the 40 infants (15%) with less than grade II hydronephrosis. Of these cases 3 had grade III or higher vesicoureteral reflux and 1 with high grade reflux required reimplantation. None of the 16 patients followed without voiding cystourethrography has required further evaluation or intervention. In all patients with negative or no voiding cystourethrography parenchyma was preserved and hydronephrosis stabilized or resolved.

CONCLUSIONS

Prenatal and postnatal ultrasound in infants should be used to guide further urological evaluation. Among infants with less than grade II hydronephrosis postnatally 15% had reflux on voiding cystourethrography, which is significantly higher than that reported among normal children (approximately 1%). However, none of the 16 infants observed without voiding cystourethrography on short-term antibiotic prophylaxis had deleterious renal events with 6 months to 4.5 years of followup. Therefore, we question the actual significance of the reflux detected in the first cohort of infants. Voiding cystourethrography can provide a definitive answer. However, we also believe that it is not absolutely mandatory based on the outcome in the observed group. With careful counseling and followup most patients with less than grade II hydronephrosis can be observed without urological sequela.

Can careful ultrasound examination of the urinary tract exclude vesicoureteric reflux in the neonate?

The aim of the study was to determine whether a urinary tract appearing normal when assessed by meticulous ultrasound (US) examination may coexist with vesicoureteric reflux (VUR) and whether a normal US scan can be used to exclude VUR, thereby avoiding unnecessary voiding cystourethrography (VCUG). The US features of 35 neonates with known VUR were reviewed. Criteria studied included pelvic dilatation above 7 mm on a transverse scan, calyceal or ureteral dilatation, pelvic or ureteral wall thickening, absence of the corticomedullary differentiation (CMD) and signs of renal dysplasia (small kidney, thinned or hyperechoic cortex and cortical cysts); all signs that have been shown to result from or to be associated with VUR. 57 refluxing renal units (RRU) were found among the 35 patients. VUR was bilateral in 22. Among the 57 RRU, at least one US anomaly that would have prompted VCUG was present in 50 (87.7%). Pelvic dilatation above 7 mm was present in 29 RRU (50.9%) only. Calyceal dilatation was present in 24 RRU, the dilatation involving the calyces but not the renal pelvis in seven. Ureteral dilatation was observed in 15 RRU. Pelvic or ureteral wall thickening was present in seven RRU. CMD was absent in 32 RRU (56.1%). US signs of dysplasia were found in 19 RRU. No US anomaly was found in seven RRU (12.3%) in six patients. A careful and meticulous US examination of the neonatal urinary tract allows the detection of over 87% of RRU by showing at least one sonographic abnormality. It is concluded that a normal appearing urinary tract on US does not usually coexist with VUR and that in such cases VCUG is not necessary.

Antenatal diagnosis of urinary tract abnormalities by ultrasonography after 28 weeks' gestation: incidence and outcome

OBJECTIVE

The objective was to establish the likelihood that antenatal upper urinary tract dilatation identified after 28 weeks of gestation will progress to significant postnatal uropathy.

STUDY DESIGN

In 5 years, 3856 fetuses had ultrasonography after 28 weeks of gestation when the mothers were first seen in advanced pregnancy for delivery appointments or for other obstetric indications. Fetuses with urinary tract anomalies had ultrasonographic surveillance after 6 days and 6 weeks of life with further evaluation as necessary.

RESULTS

Renal tract anomalies were identified in 313 fetuses, and 55 infants had significant renal tract abnormalities. There were 7 deaths; 2 infants were anephric and 5 with hydronephrosis had lethal congenital abnormalities. Dilatation of the upper urinary tract was identified in 7.7% of the fetuses (298/3856) but was transient in 216 of them (72%). Follow-up of children with transient renal pelvis dilatation found only one with a history of urinary tract infection. Obstruction occurred in 23 infants (6.0/1000) and 16 required surgical correction. Vesicoureteric reflux was identified in 14 infants (3.6/1000) and resolved by age 2 years in 64%. Unilateral multicystic renal dysplasia occurred in 8 and posterior urethral valves occurred in 3 infants.

CONCLUSION

Antenatal ultrasonography after 28 weeks' gestation identified significant renal tract abnormalities with a frequency of 14.3 per 1000 births, permitting early treatment of the asymptomatic newborn and reducing later renal damage.

Mild fetal hydronephrosis indicating vesicoureteric reflux

The management of neonates with mild hydronephrosis diagnosed antenatally is still debated. Although some of these infants are normal, it is recognised that others will have mild obstruction of the ureteropelvic junction or vesicoureteric reflux (VUR). A prospective study was performed in all newborn infants with an antenatal diagnosis of mild hydronephrosis (47 babies, 62 kidneys) born over a two year period in order to assess the frequency of VUR. Voiding cystography in 14 patients with 21 renal units showed VUR. Two patients underwent surgery and the VUR resolved; the other 12 received medical treatment. Repeat cystography was scheduled for 12-18 months later, when a high rate of spontaneous cure was observed. The remaining patients were monitored by ultrasonography but only in one case did hydronephrosis deteriorate because of the presence of severe ureteropelvic junction obstruction. It is concluded that mild dilatation of the pelvis might be an expression of a potentially severe malformation such as VUR, and a careful follow up of these cases is mandatory.

Antenatal diagnosis of pediatric surgical anomalies. Counseling the family

Improvements in screening and diagnostic techniques now mean that hundreds of congenital anomalies can be antenatally diagnosed. It is, however, impossible and inappropriate to submit all pregnant women to a barrage of investigations. Screening is necessary before specific invasive investigations are initiated. These include history, physical examination, MS-AFP screening, estriol and hCG screening, and a Level II ultrasonography scan. Once at-risk pregnancies have been identified, a multidisciplinary team approach is commenced and further studies including Level II ultrasonography, amniocentesis, chorionic villus sampling, or cordocentesis can be performed so that an accurate diagnosis is available. Counseling of the parents throughout is essential so that appropriate decisions regarding this and further pregnancies can be made.