Follow-up of infants with bilateral renal disease detected in utero. Growth and renal function

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.

The 4 year outcome following the demonstration of bilateral renal pelvic dilatation on pre-natal renal ultrasound

There is little in the literature regarding long-term prognosis in cases of fetal pyelectasis and calyceal dilatation. The aim of this study was to correlate antenatal ultrasound findings with outcome in a large group of children, most of whom had routine antenatal mid-trimester scans. 75 babies with bilateral pyelectasis and calyceal dilatation in the pre-natal period and complete radiological and clinical data were identified over a 3 year period. Pre-natal ultrasound was correlated with results of post-natal investigation and the frequency of post-natal surgery was established. Follow-up was documented to discharge or to at least 4 years of age. Prognosis was related to the degree of pelvic dilatation, but neonatal morbidity was much more likely to be associated with pre-natal calyceal dilatation and/or hydroureter. 68% (51 of 75) of babies had insignificant abnormalities on post-natal investigation, defined as either transient fetal pyelectasis and calyceal dilatation, extrarenal pelves, or transient neonatal pyelectasis and calyceal dilatation. Five babies died in the neonatal period, all classified as either moderate or severe disease. Of the surviving 70 cases (93.3%), 27% had renal anomalies that required treatment by prophylactic antibiotics or surgery. The remaining babies were conservatively managed and followed as outpatients. One child required transplantation and a further two had a severe degree of chronic renal failure by the age of 4 years. These data will be of value in prospective counselling.

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.

Mortality after an antenatal diagnosis of foetal uropathy

A longitudinal study identified 987 foetal uropathies over a 13-year period. There were 147 deaths. Forty infants died as a result of a lethal uropathy in the presence of associated congenital anomalies. Sixty-six infants with an isolated uropathy died. There were 4 cot deaths, 2 obstetric related deaths, and 34 deaths caused by associated congenital anomalies. There was 1 termination of pregnancy following a false-positive diagnosis of uropathy. Of the 147 deaths, 34 occurred postnatally, 20 within 24 hours. Twenty-nine infants were spontaneously aborted. There were 78 terminations of pregnancy, 43% occurring after 24 weeks of gestation. There was complete concordance in antenatal and postnatal diagnoses in 113 (77%) cases and incomplete concordance in 19 (13%) cases. There were 14 false-negative diagnoses (9.5%). The relative frequency of different lethal congenital uropathies is detailed. Accurate in utero diagnosis of foetal uropathy and hence prediction of outcome is possible. The relatively late gestational age at time of diagnosis remains a constraint when fatal malformations would otherwise prompt termination of pregnancy.

Risk factors in internal urinary system malformations

Risk factors were studied in 370 children with internal urinary system (IUS) anomalies, coming from 105,374 consecutive births of known outcome. The incidence of IUS malformations was 3.51 per 1,000 births. Diagnosis was performed prenatally in 54.4% of patients. Two hundred and fifty-two patients had isolated IUS anomalies; 118 (31.8%) of the children had at least one non-urinary malformation. Fifty-five infants (14.8%) had recognized chromosomal and non-chromosomal syndromes. The more frequent non-urinary malformations were cardiac, digestive and limb anomalies. For each case a control was studied. The following features were assessed: sex ratio, parity and previous pregnancies, parental age, residency, education, ethnic origin, length, head circumference and weight at birth, genetic and environmental factors. Odds ratio values were calculated for risk factors. Weight, length and head circumference at birth were less than in the controls and the weight of the placenta was lower. Pregnancies with IUS anomalies were more often complicated by oligo-amnios and threatened abortions. Oligo-amnios was more frequent in pregnancies in which babies had multiple malformations and recognized syndromes with IUS anomalies. One child of every three with IUS anomalies had an extra-urinary malformation, which is 12 times the incidence of such malformation in our population. There was an increase in consanguinity in the parents of our patients. The incidence of IUS anomalies in first-degree relatives was 2.9%. First-degree relatives had more non-urinary malformations than controls (7.02 vs 3.2%). Our study demonstrated the high capacity of a general ultrasound screening programme to detect fetal malformations affecting the urinary tract.

Severe bilateral renal disease: correlation of antenatal and autopsy findings

We report 20 infants with severe bilateral renal disease examined by prenatal ultrasound and by autopsy. In 17, the prenatal and pathologic diagnoses correlated well. Although the prenatal and autopsy findings differed in the three remaining cases, the autopsy confirmed the presence of severe bilateral renal abnormalities. All 20 pregnancies were complicated by oligohydramnios, which was severe in 60 per cent. Most of these fetuses had malformation of other organ systems. This series supports the utility of prenatal ultrasound examinations, but emphasizes the need for postnatal evaluation of congenital renal disease including pathologic examination of tissue when possible for correct classification and genetic counselling.