Caution in antenatal intervention

Consensus on the Management of Posterior Urethral Valves from Antenatal Period to Puberty

The need for successful management of posterior urethral valves always captivates the minds of pediatric surgeons. Its success, however, depends on several factors ranging from prenatal preservation of upper tracts to postoperative pharmacological compliance. Regardless of measures available, some cases do not respond and progress to end stage. The management depends on several issues ranging from age and severity at presentation to long-term follow-up and prevention of secondary renal damage and managing valve bladder syndrome. This article is based on a consensus to the set of questionnaires, prepared by research section of Indian Association of Paediatric Surgeons and discussed by experienced pediatric surgeons based in different institutions in the country. Standard operating procedures for conducting a voiding cystourethrogram and cystoscopy were formulated. Age-wise contrast dosage was calculated for ready reference. Current evidence from literature was also reviewed and included to complete the topic.

Fetal lower urinary tract obstruction

The authors present an overview of the prenatal diagnosis, evaluation, contemporary intervention, and antenatal management of lower urinary tract obstruction. They review early experimental models that confirmed the relation between urinary tract obstruction and renal fibrocystic dysplasia and that early in utero relief of the obstruction could prevent irreversible renal injury. Subsequent studies of the electrolyte and protein concentrations in fetal urine from human cases established prognostic threshold values and helped to develop an algorithm to select candidates for antenatal therapy. Although shunting has improved survival, long-term morbidities remain a significant challenge.

Fetoscopic Placement of a Transurethral Stent for Intrauterine Obstructive Uropathy

PURPOSE

Fetal urinary obstructive uropathy and consecutive oligohydramnios result in a poor outcome. Usually renal insufficiency and life threatening lung hypoplasia have developed at term. We report a case of in utero fetal cystoscopy and successful placement of a transurethral vesico-amniotic Double-J (Medical Engineering Corp., New York, New York) stent. Indications, results and the potential benefits of different techniques are discussed.

MATERIAL AND METHODS

A 36-year-old woman (primipara) was evaluated at week 26 due to a male fetus with bilateral hydronephrosis, massive distended bladder and an open posterior urethra. Using local anesthesia the fetal bladder was punctured, a 2.6 mm endoscope was inserted and a wire was advanced antegrade through the penis. A 2.8Fr Double-J stent was then placed between the bladder and amniotic cavity.

RESULTS

The bladder drained into the amnion, hydronephrosis disappeared and the lung developed normally. At week 37 a healthy infant was delivered who voided spontaneously.

CONCLUSIONS

After careful selection of candidates for fetal intervention in obstructive uropathy direct vision fetoscopy and transurethral stent placement can be performed in patients with oligohydramnios, favorable urinary electrolytes and normal appearing kidneys.

Operative fetoscopical management of intrauterine obstructive uropathia by urethral stent

We report on an innovative therapeutic attempt in a case with obstructive uropathia in a fetus. Placement of an anterograd urethral stent was performed in the 26th gestational week. Transurethral catheterization via the fetal megacystis, the urethra and the orificium externum of the penis was feasible during fetal endoscopy (Fetendo). During serial ultrasound scans from the 27th to the 36th gestational week a normalization of the amniotic fluid volume was observed. The postpartal evaluation demonstrated that the kidney structure, values of kreatinin serum levels and renal clearance were in the normal range. The boy's development after the seventh month is completely normal. Fetendo with urethral stent application for obstructive uropathy should be performed for the carefully selected patient with oligohydramnion and normal kidney appearance.

Successful early pyeloplasty in infants

BACKGROUND

Early pyeloplasty for the treatment of congenital ureteropelvic junction obstruction to maximize nephron salvage is justified only if potential hazards of operating on small infants are avoided.

METHODS

The records were analyzed of all infants who underwent pyeloplasty over a 5-year period. Open pyeloplasty was performed if collecting systems had deteriorated or were demonstrated to be obstructed; it was also performed for severe cases of hydronephrosis. Outcome of surgery in the younger infant (patients <2 months of age) was compared with the older infant group (patients >2 months of age). Preoperative evaluation in case of mild or moderate hydronephrosis was directed toward ruling out a non-obstructed collection system and included voiding cystourethrography, and serial ultrasonography and/or dual isotope diuretic renography. Postoperative assessment consisted of serial ultrasonography and/or nuclear imaging to confirm decompression and relief of obstruction.

RESULTS

A total of 24 pyeloplasties were performed on 22 patients in the younger infant group (two bilateral) and 30 were performed on 27 infants in the older infant group (three bilateral). The only significant differences between the groups were as follows: patients in the younger infant group were likely to present in utero (75%, p = 2.69), whereas those in the older infant group were more likely to present with a urinary tract infection (48%, p = 4.12). During follow-up examination, 23 renal units in the younger infant group and 24 in the older infant group were judged to be stable or improved. Four kidneys were not salvaged after pyeloplasty, one in the younger infant group and three in the older infant group.

CONCLUSIONS

Good results of pyeloplasties performed in the infants in this series support early correction of ureteropelvic junction obstruction in infants.

Fetal surgery for posterior urethral valves: long-term postnatal outcomes

OBJECTIVE

Fetal intervention for obstructive uropathy was first performed at the University of California, San Francisco in 1981. Indications for treatment were bilateral hydronephrosis with oligohydramnios. Preintervention criteria included fetal urinary electrolytes with beta-microglobulin levels, karyotyping, and detailed sonography specifically looking for renal cortical cysts. We reviewed the outcomes of children who underwent fetal intervention with specific long-term follow-up in patients who were found postnatally to have posterior urethral valves.

METHODS

A retrospective review of the University of California, San Francisco fetal surgery database was performed for patients with a prenatal diagnosis of obstructive uropathy. Medical records from 1981 to 1999 were reviewed. Long-term follow-up was documented if the cause of the urinary tract obstruction was posterior urethral valves. We collected data points, focusing on time and type of intervention, fetal urinary electrolytes, appearance of fetal kidneys, present renal function, length of follow-up, and present status of the urinary tract.

RESULTS

Forty patients were evaluated for fetal intervention; 36 fetuses underwent surgery during this time period. Postnatal confirmation of posterior urethral valves was demonstrated in 14 patients. All patients had favorable fetal urinary electrolytes. Mean gestational age at intervention was 22.5 weeks. The procedures performed included creation of cutaneous ureterostomies in 1, fetal bladder marsupialization in 2, in utero ablation of valves in 2, and placement of vesicoamniotic catheter in 9. Six deaths occurred before term delivery with premature labor and the newborns succumbing to respiratory failure. One pregnancy was terminated electively because of shunt failure and declining appearance of fetal lungs and kidney. The remaining 8 living patients had a mean follow-up of 11.6 years. Chronic renal disease with abnormal serum creatinine was present in 5 patients. Two patients have undergone renal transplantation, and 1 is awaiting organ donation. Five of the 8 living patients have had urinary diversion with vesicostomy, cutaneous ureterostomy, or augmentation cystoplasty with later reconstruction.

CONCLUSIONS

Fetal intervention for posterior urethral valves carries a considerable risk to the fetus with fetal mortality rate of 43%. The long-term outcomes indicate that intervention may not change the prognosis of renal function or be a predictor for possible urinary diversion. Despite all of these patients' having favorable urinary electrolytes, this did not seem to have any implication postnatally. When counseling families about fetal intervention, efforts should be focused on that intervention may assist in delivering the fetus to term and that the sequelae of posterior urethral valves may not be preventable. Fetal surgery for obstructive uropathy should be performed only for the carefully selected patient who has severe oligohydramnios and "normal"-appearing kidneys.

Posterior urethral valves: pre- and postnatal management

Posterior urethral valves are a common problem encountered by pediatric urologists. The diagnosis is most frequently suggested by antenatal screening ultrasound. A variety of pre- and postnatal parameters have been identified to aid in predicting ultimate renal outcome. These prognostic tools are invaluable to the clinician for counseling parents and for choosing appropriate management. Several approaches to the treatment of patients with posterior urethral valves exist, and the ideal strategy is debatable. As technology evolves, more options for early intervention become available. Whether early detection and antenatal intervention improve patient outcome remains to be proven.

Consensus on the prenatal management of antenatally detected urological abnormalities

PURPOSE

The incidence of an antenatally detected genitourinary abnormality is 0.5% of all pregnancies assessed, and rarely is antenatal intervention indicated. A survey of pediatric urologists was undertaken to evaluate current practice patterns and recommendations regarding the need to intervene in the antenatal period.

MATERIALS AND METHODS

A survey instrument was mailed to all members of the Society for Fetal Urology. There were 7 case scenarios that addressed critical decision points in patients with antenatally detected genitourinary abnormalities.

RESULTS

A total of 112 of 188 Society for Fetal Urology members (60%) completed the survey. Observation with serial ultrasound was recommended for a 32-week fetus with ureteropelvic junction obstruction. For a 36-week fetus with suspected posterior urethral valves without oligohydramnios most respondents elected no intervention with a minority favoring early delivery. For a 23-week fetus with suspected posterior urethral valves and oligohydramnios with normal bladder electrolytes most respondents agreed with a vesicoamniotic shunt. There was no clear consensus for a 20-week fetus with suspected posterior urethral valves, oligohydramnios and a nonfunctioning right kidney. Most respondents recommended serial ultrasound to follow an 18-week fetus with suspected posterior urethral valves and normal amniotic fluid. Antenatal intervention was not recommended for a 20-week fetus with bilateral renal cystic disease, and most respondents elected no intervention for a 28-week fetus with a solitary kidney with suspected ureteropelvic junction obstruction and normal amniotic fluid.

CONCLUSIONS

Situations that warrant antenatal intervention for a genitourinary abnormality are exceedingly low and may include cases of oligohydramnios, suspected favorable renal function and the absence of life threatening congenital abnormalities. In cases with normal amniotic fluid antenatal intervention is not recommended regardless of the detected abnormality. There is an emerging trend toward early delivery of fetuses with severe genitourinary abnormalities, normal amniotic fluid and confirmed lung maturity.

Consensus on the prenatal management of antenatally detected urological abnormalities

PURPOSE

The incidence of an antenatally detected genitourinary abnormality is 0.5% of all pregnancies assessed, and rarely is antenatal intervention indicated. A survey of pediatric urologists was undertaken to evaluate current practice patterns and recommendations regarding the need to intervene in the antenatal period.

MATERIALS AND METHODS

A survey instrument was mailed to all members of the Society for Fetal Urology. There were 7 case scenarios that addressed critical decision points in patients with antenatally detected genitourinary abnormalities.

RESULTS

A total of 112 of 188 Society for Fetal Urology members (60%) completed the survey. Observation with serial ultrasound was recommended for a 32-week fetus with ureteropelvic junction obstruction. For a 36-week fetus with suspected posterior urethral valves without oligohydramnios most respondents elected no intervention with a minority favoring early delivery. For a 23-week fetus with suspected posterior urethral valves and oligohydramnios with normal bladder electrolytes most respondents agreed with a vesicoamniotic shunt. There was no clear consensus for a 20-week fetus with suspected posterior urethral valves, oligohydramnios and a nonfunctioning right kidney. Most respondents recommended serial ultrasound to follow an 18-week fetus with suspected posterior urethral valves and normal amniotic fluid. Antenatal intervention was not recommended for a 20-week fetus with bilateral renal cystic disease, and most respondents elected no intervention for a 28-week fetus with a solitary kidney with suspected ureteropelvic junction obstruction and normal amniotic fluid.

CONCLUSIONS

Situations that warrant antenatal intervention for a genitourinary abnormality are exceedingly low and may include cases of oligohydramnios, suspected favorable renal function and the absence of life threatening congenital abnormalities. In cases with normal amniotic fluid antenatal intervention is not recommended regardless of the detected abnormality. There is an emerging trend toward early delivery of fetuses with severe genitourinary abnormalities, normal amniotic fluid and confirmed lung maturity.

Fetuses and infants with congenital urinary system anomalies: correlation between prenatal ultrasound and postmortem findings

OBJECTIVE

Detection of congenital urinary system anomalies is an important part of the prenatal ultrasound examination. The present study compares prenatal ultrasonographic findings and postmortem examinations of fetuses and infants with renal and urinary tract anomalies.

DESIGN

Criteria for inclusion were an ultrasound examination at the National Center for Fetal Medicine (Trondheim, Norway) and autopsy performed during the period 1985-94. Results from the ultrasound examination and autopsy regarding urinary system anomalies were categorized according to the degree of concordance.

RESULTS

Urinary system anomalies were found in 112 (27%) of 408 fetuses with congenital anomalies. The renal and/or urinary tract anomaly was the principal reason for induced abortion or cause of death in 50 cases (45%). In 97 (87%) of the 112 cases there was full agreement between the ultrasound observations and the autopsy findings. In five cases the autopsy revealed minor findings not mentioned in the ultrasound report. The main diagnosis was thus correct in 102 cases (91%). In four cases major autopsy findings had not been found by ultrasound examination; in another four, none of the autopsy findings were suspected by ultrasound, and in two, minor ultrasound findings were not confirmed at autopsy.

CONCLUSIONS

The accordance between ultrasound diagnoses and postmortem examinations proved to be satisfactory. The close co-operation between ultrasonographers and perinatal pathologists is mutually beneficial. In addition to complementing prenatal diagnosis, postmortem examination is of vital importance for the quality control of ultrasonography in fetal diagnosis and plays an important role in genetic counseling.

Fetal interventions for obstructive uropathy

Obstructive uropathy is a significant source of morbidity and mortality in the neonate and infant, despite advances in postnatal management. Diagnosis is typically made early in the second trimester on the basis of sonographic measurements. In utero therapy holds promise for improved outcomes by preventing progressive urinary tract damage and permitting drainage of urine into the amniotic space to minimize the pulmonary sequelae of oligohydramnios. Multiple studies with animal models have showed the benefits of midgestational intervention, but large prospective, randomized studies have not yet been performed to confirm these findings in humans. Standardization of the diagnostic evaluation allows for refined patient selection, resulting in improved postnatal outcomes after fetal vesicoamniotic shunting. Research into the role of specific growth factors and immunoproteins in renal development and function may further improve patient selection and outcome. This article reviews diagnosis, technique, and outcomes for fetal treatment of obstructive uropathy.

Fetal uropathy

Our understanding of the causes, mechanisms, and prenatal management of fetal obstructive uropathy has increased significantly. Improved methods of prenatal evaluation have allowed the better selection of fetuses for invasive therapy, and studies indicate better survival and renal outcomes in carefully selected cases. New biological markers in fetal urine may provide a better understanding of the pathological processes of renal damage, additional prognostic markers, and lead to non-surgical approaches to preventing renal damage.

Follow-up of children after fetal treatment for obstructive uropathy

BACKGROUND

Improvement in the ability to evaluate fetuses with obstructive uropathy, combined with technologic advances, has allowed successful fetal treatment of these conditions in Japan. We analyzed the prenatal and postnatal clinical courses of patients who underwent shunt placement in utero.

METHODS

We treated 6 patients who underwent fetal intervention and were transferred to us for urologic management. Gestational age at detection of abnormalities ranged from 11 weeks to 31 weeks, and fetal intervention was done between 16 weeks and 32 weeks. Excluding 1 infant who was delivered 6 days after the intervention, the mean period between shunt placement and delivery was 17 weeks.

RESULTS

Urologic pathology included prune belly syndrome with urethral hypoplasia in 3 patients, cloacal anomaly in 1, posterior urethral valves in 1, and pelviureteric junction stenosis of a solitary kidney in 1. Four patients required ventilation support in the neonatal period, and 2 of them suffered frequent infections during follow-up. Five patients who underwent vesico-amniotic shunt placement continue to require clean intermittent catheterizations via vesicostomy because of hypoactive detrusors and hypoplastic urethras. After urologic treatment, serum creatinine in 5 patients reached a minimum of less than 0.4 mg/dL at some time during the first year of life. Another patient with a minimum creatinine level of 1.0 mg/dL has moderate renal insufficiency.

CONCLUSION

From our series, it appears that early (before 20 weeks of gestation) shunt placement in severe lower urinary tract obstruction may benefit renal and pulmonary function. However, its efficacy in regard to bladder function remains questionable: shunt placement does not permit regular storage and evacuation, which may be essential for functional bladder development.

Postnatal management of hydronephrosis diagnosed in utero

In this review we identify the causes of antenatal hydronephrosis and detail management options. A large majority of these patients can be treated safely and effectively after birth.

Minimal hydronephrosis in the fetus: clinical significance and implications for management

PURPOSE

We further define the natural history and management of minimal fetal hydronephrosis.

MATERIALS AND METHODS

Experience with minimal fetal hydronephrosis (renal pelvic diameter 4 to 10 mm. before 20 weeks of gestation and 5 to 10 mm. from 20 to 24 weeks) was reviewed for 18 months at New England Medical Center.

RESULTS

The incidence of minimal fetal hydronephrosis was 2.2% in the 5,900 fetuses screened by ultrasound. In 63% of cases prenatal ultrasound was done more than once, and revealed that dilatation of the urinary tract was stable during gestation in 31 (25%), and became normal in 35 (29%) and worse in 11 (9%). A total of 63 patients (103 renal units) followed for up to 1 year underwent postnatal sonography. Those with abnormalities were screened with a voiding cystourethrogram and renal scan, including 40 with normal postnatal ultrasound and no changes on subsequent evaluation. Of the 23 patients with abnormal findings 4 had functionally significant ureteropelvic junction obstruction and 1 had severe vesicoureteral reflux. A retrospective analysis of the sonograms of patients with minimal fetal hydronephrosis and persistence or progression of hydronephrosis revealed calicectasis, progression of minimal fetal hydronephrosis in utero and/or abnormal renal echogenicity in each fetus.

CONCLUSIONS

Our study shows that in a small but significant number of fetuses minimal fetal hydronephrosis will progress, whereas in most it will resolve.

Prognosis for patients with prenatally diagnosed posterior urethral valves

Children in whom posterior urethral valves are diagnosed shortly after birth are at higher risk for renal failure than children in whom posterior urethral valves are diagnosed later in life. The influence of prenatal diagnosis of posterior urethral valves on clinical outcome has not been established. We collected data on children with posterior urethral valves treated since birth at our hospital between 1975 and 1990. The clinical outcomes for 8 patients diagnosed prenatally and 15 diagnosed neonatally were compared. Of the 8 patients in the prenatal group 5 (64%) had renal failure compared to 5 of 15 (33%) in the neonatal group (p greater than 0.05). Nadir creatinine of more than 1.2 mg./dl. correlated with the development of renal failure in all patients in the neonatal and prenatal groups. There was 1 death in the prenatal group. In our experience prenatal diagnosis of posterior urethral valves has grave implications, including a 64% incidence of progressive renal failure and a 64% incidence of transient pulmonary failure. Oligohydramnios and postnatal pulmonary insufficiency are predictive of progressive renal failure. Earlier diagnosis and treatment of children with posterior urethral valves did not improve the clinical prognosis.

Effect of in utero vesicostomy on pulmonary hypoplasia in the fetal lamb with bladder outlet obstruction and oligohydramnios: a morphometric analysis

A model of early gestation bladder outlet obstruction and oligohydramnios in the fetal lamb is characterized by small, immature lungs (pulmonary hypoplasia). The current study examines how in utero relief of urinary tract obstruction produced early in gestation modifies pulmonary hypoplasia. Bladder obstruction was created at 60 days gestation in fetal sheep (term = 140 days); 11 fetuses then underwent in utero decompression at 95 to 100 days; six were left obstructed. Five normal fetuses served as controls and two underwent sham obstruction and vesicostomy. All were delivered and sacrificed near term (135 days), the right lung was inflation-fixed and its volume determined. Relative volumes of alveoli, alveolar ducts, and tissue, alveolar surface area, and alveolar numerical density were estimated morphometrically. Kidneys were examined histologically. In all animals persistent bladder obstruction produced oligohydramnios. Bladder obstruction to term produced pulmonary hypoplasia with a mean right lung volume-to-body weight ratio (LV:BW) of 14.3 cc./kg. (normal = 36.4, p less than 0.001). Structural immaturity was evidenced by an airspace fraction of only 57% (normal = 68%, p less than 0.05). Kidneys in these animals were not dysplastic; there was hydronephrosis or evidence of spontaneous urinary decompression. In eight of the 11 animals, decompression improved the LV:BW ratio to 28.4 cc./kg. (vs. obstructed, p less than 0.001; vs normal, p less than 0.05) and normalized maturity. All had increased amniotic fluid at delivery; kidneys in 7/8 animals were normal, and the other had moderate hydronephrosis. One of the 11 animals had normal kidneys, oligohydramnios, immature lungs, but with normal volume. Oligohydramnios was present in the other two of 11 fetuses despite successful decompression and they had markedly dysmorphic kidneys and profoundly hypoplastic and immature lungs (LV:BW 5.1 cc./kg.). Even after 35 days (25% gestation) of obstruction, in utero urinary tract decompression permits better lung growth and maturation than in persistently obstructed animals. The degree of renal damage from obstruction appears to be a critical determinant in the correction of pulmonary hypoplasia.

Medical sonography: reproductive effects and risks

While it is clear that the levels and types of medical sonography that have been used in the past have no measurable risks, it would be inaccurate to label the modality of ultrasound as totally safe regardless of exposure. Most agents have reproductive risks and even teratogenic risks if the exposure is raised sufficiently. Thus the prudent use of sonography means that clinicians and designers of equipment have to maintain exposures far below the risks that have been demonstrated in animal studies and from the knowledge obtained about the physical changes that can be produced in humans as the absorbed dose is elevated. The reproductive risks were evaluated using five criteria: 1) human epidemiology, 2) secular trend data, 3) animal experiments, 4) dose response relationships, and 5) biologic plausibility. The analysis reveals that the human epidemiology does not indicate that diagnostic ultrasound presents a measurable risk to the developing embryo or fetus. Animal studies also indicate that diagnostic levels of ultrasound are safe and do not elevate the fetal temperature into the region where deleterious embryonic and fetal effects will occur. Because higher exposures of ultrasound can elevate the temperature of the embryo, the use of diagnostic procedures and the design of sonographic equipment should take into consideration the hyperthermic potential of higher exposures of ultrasound and the hypothetical additional risk of performing sonography on pregnant patients who are febrile. It would appear that if the embryonic temperature never exceeds 39 degrees C, then there is no measurable risk. We suggest that sonography (the field) and sonogram (the procedure) are the most appropriate and least anxiety provoking terms.

Evaluation of fetal renal function: unreliability of fetal urinary electrolytes

In the fetus with bilateral hydronephrosis it has been reported that a normal volume of amniotic fluid, absence of renal cortical cysts, urinary sodium less than 100 mEq./l., chloride less than 90 mEq./l. and osmolarity less than 210 mOsm. are prognostic factors indicative of good renal function, whereas oligohydramnios, cortical cysts and higher urinary levels of sodium, chloride or osmolarity suggest irreversible renal dysplasia. We report 5 cases in which the fetal urinary electrolytes were not predictive of ultimate renal function. In 3 instances fetal urinary electrolytes and osmolarity were abnormally elevated but the infants survived without ventilatory support. In 2 of these 3 patients the volume of amniotic fluid was normal. Diagnoses included posterior urethral valves, prune belly variant and bilateral ureteropelvic junction obstruction. In 2 cases with oligohydramnios fetal urinary electrolytes were suggestive of satisfactory renal function but the infants died of pulmonary hypoplasia and had bilateral renal dysplasia, prune belly syndrome and urethral atresia. Presently, the volume of amniotic fluid remains the most important prognostic sign in the fetus with bilateral hydronephrosis. Further work is necessary to identify other factors that may be more reliable as prognostic indexes of fetal renal function.

Ultrasound screening for fetal urinary tract malformations: a prospective study in general population

Routine ultrasound examination at a first level ultrasound unit was performed on 4586 fetuses in general pregnant population at 18 and 34 weeks, to detect urinary tract malformations. Suspected renal abnormality was confirmed by postnatal investigations. Infants were followed up to 2-4 years to detect any renal malformations missed in screening. Urinary tract abnormalities were observed antenatally in 27 fetuses, eight cases at 18 weeks, and 19 cases at 34 weeks. An anteroposterior diameter of renal pelvis of 1 cm or more was the criterion for fetal hydronephrosis, which was the main ultrasound finding in 18 fetuses showing 24 hydronephrotic kidneys. In five cases, slight hydronephrosis disappeared spontaneously after birth, explaining the five 'false positive' cases of the study. Four children had renal abnormalities that were missed antenatally. The incidence of true urinary tract malformations detected by screening antenatally was 0.48%, and the overall incidence after 2-4 years follow-up was 0.57%, which is much higher than reported earlier in series without routine ultrasound screening. The antenatal screening showed a sensitivity of 84.6%, a specificity of 99.9%, a positive predictive value of 81.5%, and a negative predictive value of 99.9%. The main differential diagnostic problems occurred in two fields: in differentiating (1) functional hydronephrosis from obstructive uropathy, and (2) multicystic renal dysplasia of Potter's type IV from severe hydronephrosis. The prenatal diagnosis in cases with definitive renal abnormality corresponded to the postnatal diagnosis in 19/22 (86.4%) of the cases. 68% of the infants with urinary tract anomaly survived, 60% of them undergoing postnatal surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Maps for diagnosis and management of antenatal urinary tract dilatation

Despite advances in radiological imaging techniques, the ideal management of antenatally diagnosed hydronephrosis remains controversial. A map, showing diagnostic and management pathways, has been designed in an attempt to provide maximum information from the most appropriate and minimum number of investigations.

Bilateral fetal uropathy: what is the outlook?

OBJECTIVE

To assess the morbidity and mortality associated with a prenatal diagnosis of bilateral fetal uropathy.

DESIGN

Retrospective study.

SETTING

Departments of radiology, paediatric surgery, obstetrics, and pathology in two teaching hospitals that serve as referral centres for the Yorkshire region.

PATIENTS

126 Cases of fetal uropathy were referred either prenatally or postnatally from hospitals in Yorkshire between August 1982 and December 1987. The disease was bilateral in 54 cases and unilateral in 72 cases. In 14 cases bilateral fetal uropathy was associated with coexistent disease.

INTERVENTIONS

All cases were managed individually by an obstetrician after discussion with the radiologists and paediatric surgeons. Babies who survived were treated prophylactically with antibiotics after delivery and were operated on if appropriate.

END POINT

Assessment of prognosis for long term renal function for each baby referred between August 1982 and December 1987: follow up ranged from six months to five years.

MEASUREMENTS AND MAIN RESULTS

Of the 54 fetuses with bilateral fetal uropathy, 13 were terminated as the prenatal findings of ultrasonography were considered to be incompatible with long term survival. Ten of the liveborn babies died, five of renal or pulmonary insufficiency, or both, and five of associated congenital anomalies. Thirty one infants survived to follow up; four of these had serious coexistent disease and two had impaired renal function. Thus the overall mortality was 43% and the morbidity rate 19%. The renal anomaly was associated with other serious disease in 14 cases (26%) compared with two (3%) of the 72 cases of unilateral fetal uropathy. All but two of the 27 infants with isolated bilateral urinary tract disease had excellent prospects for survival.

CONCLUSION

Although bilateral fetal uropathy is associated with a high morbidity rate and mortality, careful prenatal assessment can help to identify fetuses with a poor prognosis. The outlook for a fetus with isolated renal disease if treated promptly after delivery is excellent and compares favourably with that reported after prenatal surgical intervention.