Urological Diagnosis in Utero

Arch Dis Child: first published as 10.1136/adc.59.10.913 on 1 October 1984. Downloaded from Archives of Disease in Childhood, 1984, 59, 913-915 Urological diagnosis in utero The detection of a fetal anatomical abnormality on a to 34 weeks' gestation) remain theoretical and have maternal ultrasound scan is an increasingly common to be offset against the increased morbidity of event-in district hospitals as well as teaching premature birth. Furthermore, ultrasound imaging centres. A wide range of congenital abnormalities cannot distinguish dilatation which is the result of an have now been identified before birth but anomalies obstruction, where there may be a benefit in early of the urinary tract are particularly well visualised drainage, from non-obstructive dilatation (for ex- and are relatively common (1 in 1000 to 1 in 2000 ample vesico-ureteric reflux, mild prune belly syn- live births). How might a paediatrician advise an drome) where surgical intervention may never be obstetrician colleague after the discovery of an required. In the event of premature labour occur- abnormality of the fetal urinary tract and how is the ring spontaneously after 34 weeks' gestation it affected infant best managed after delivery? would, however, be reasonable to allow it to proceed. Prenatal treatment? In utero transfer Drainage of the obstructed fetal urinary tract can now be accomplished by the insertion of a supra- While it may be beneficial for a baby with gastro- pubic catheter to drain fetal urine from the bladder schisis or diaphragmatic hernia to be born at the into the amniotic fluid. The rationale behind pre- centre where emergency surgery will be undertaken, natal treatment has been considered in a previous the advantages of in utero transfer for urinary tract annotation.' Unfortunately, the possible benefits of abnormalities are less certain. Most patients can be intrauterine drainage claimed by some workers have managed safely by instituting antibiotic prophylaxis copyright. not yet been realised in clinical practice. The results in the first day of life and by prompt referral to a published so far2 3 suggest that renal dysplasia and paediatric urologist or nephrologist. There is a pulmonary hypoplasia are already severe and irre- strong case for coordinating the investigation and versible by the time the pathology is first detected initial surgical and medical management of these on ultrasound scanning (usually between 14 and 18 infants in regional centres which offer specialised weeks' gestation). In addition, there is no good imaging as part of a paediatric urological and evidence that the renal function of surviving infants nephrological service. has been favourably modified by prenatal treat- http://adc.bmj.com/ ment. Although there may be a case for continuing Investigation research in specialised centres, intrauterine drainage cannot yet be applied to clinical practice. The first priority is to confirm the antenatal diagno- Termination of pregnancy sis, to determine whether both kidneys are present, and to assess their size and the degree of any It is difficult to argue against offering termination of dilatation of the collecting systems. Turnock and pregnancy whenever bilateral hydronephrosis is Shawis (pages 962-965 of this issue) found that the found on repeated ultrasound scans before 20 original antenatal anatomical diagnosis proved to be on September 29, 2021 by guest. Protected weeks' gestation. Oligohydramnios may be difficult incorrect in 13 of 32 cases (although in only three to assess at this stage, but, when present, is further infants was the pathology eventually shown to be evidence of a poor prognosis. Fewer than a quarter outside the urinary tract). Ultrasound examination of fetuses with bilateral hydronephrosis resulting is therefore the first investigation and should be from bladder outlet obstruction will survive with performed within the first day of life. If unequivocal anything approaching normal renal function. dilatation is found the next step is to proceed to Serious congenital abnormalities of the urinary tract micturating cystourethrography to investigate blad- are usually sporadic defects and the chances of der outlet obstruction or vesico-ureteric reflux as further children being affected in this way are possible causes. In conjunction with this investiga- minimal. tion a plain radiograph of the abdomen and spine should be performed to detect any possible coexis- Early delivery tent anomalies such as hemivertebrae or sacral agenesis. In most cases these investigations will The advantages of early delivery (for example at 32 enable an early anatomical diagnosis to be made 913 Arch Dis Child: first published as 10.1136/adc.59.10.913 on 1 October 1984. Downloaded from 914 Thomas with a high degree of accuracy. In neonates whose Bilateral upper tract dilatation. Bladder outlet ultrasound scan shows a seemingly normal urinary obstruction is the most likely cause of this. Urinary tract or only minimal dilatation, no further inves- tract drainage should be established by the passage tigation is indicated at this stage. The further of a urethral or suprapubic catheter under antibiotic management of these patients is considered below. cover. Surgical treatment (for example resection of Imaging, which is dependent on renal function urethral valve tissue or the formation of a temporary (intravenous urography and isotopes), is frequently cutaneous vesicostomy) will normally be performed unhelpful or frankly misleading during the period of in the first week of life. In cases of bilateral upper so called 'transitional nephrology' when both glom- tract dilatation without bladder outlet obstruction erular and tubular function are poor. If possible, (for example prune belly syndrome, neuropathic therefore, intravenous urography should be de- bladder, or bilateral primary vesico-ureteric reflux) ferred until around three or four weeks of age. surgical intervention will not necessarily be re- Intravenous urography may be helpful in identifying quired. Vesicostomy may, however, be helpful if duplex systems (which are not always evident on recurrent infection is a problem. ultrasound and micturating cystourethrography) and should be undertaken as part of the investigation of any renal mass which appears to be solid on Unilateral hydronephrosis. The optimal manage- ultrasound. Furthermore, most paediatric urologists ment of infants with pelvi-ureteric junction obstruc- would still wish to see an intravenous urogram tion is still the subject of discussion, but Ransley and before embarking on renal surgery. The most Manzoni (in data presented at a meeting of the commonly used isotopes in this age group are Urological Section of the Royal Society of Medi- Technicium 99 DTPA and Technicium 99 DMSA. cine, London, May 18, 1984) who have studied 24 Both are handled abnormally by the neonatal infants with antenatally diagnosed pelvi-ureteric kidney and are subject to the same limitations as obstruction, have recently suggested that a con- intravenous urography. Isotope imaging becomes servative approach is appropriate in up to two thirds of cases. If renal function is good (40% to 50% more reliable at around three to four weeks of age copyright. and is then very helpful in planning surgical manage- differential function on isotope scan) even though ment. Technicium 99 DTPA is excreted into the drainage seems to be impaired, these children can urine and is used principally to investigate obstruc- be safely observed and followed with ultrasound and tion. Technicium 99 DMSA is conventionally used isotope imaging at intervals. Pyeloplasty can be to locate functioning renal tissue and to quantify the deferred until symptoms supervene or function distribution of renal function between the two deteriorates. When unequivocal obstruction is com- kidneys. bined with moderate impairment of function (20% to 40% on isotope imaging) pyeloplasty should normally be performed at around one month of age. http://adc.bmj.com/ Treatment When function is poor (0% to 20%) a period of percutaneous nephrostomy drainage may allow A broad scheme of management can be defined. sufficient recovery to allow pyeloplasty rather than nephrectomy to be performed. Normal ultrasound examination. In patients in whom the scan performed in the neonatal period Multicystic kidney. Functioning renal tissue is com- does not confirm the antenatal findings no further on September 29, 2021 by guest. Protected investigation need be undertaken, but it would be pletely absent in this lesion-which may resemble wise to repeat the ultrasound imaging at three hydronephrosis on ultrasound. Most cases are months of age. associated with ureteric atresia and ascending infection is, therefore, unlikely. Hypertension or malig- nant change in later life are cited as justification for Minor dilatation (bilateral or unilateral). Some of nephrectomy, but these risks are probably minimal. these children will have vesico-ureteric reflux and if There is no need to remove a multicystic kidney in current thinking on the aetiology of renal scarring is the neonatal period unless the mass is particularly correct, the greatest risk from infection is within the large or the diagnosis is in doubt. Nephrectomy can first year of life. For these reasons I favour a be safely deferred until 6 to 12 months of age. micturating cystogram in such cases. If reflux is found, antibiotic prophylaxis should be begun, but if reflux is not present the ultrasound study should be Unilateral megaureter.

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