Postnatal management of infants with antenatally detected hydronephrosis

Abstract

With the increasing use of antenatal sonography, fetal hydronephrosis has been reported more frequently. Because of the lack of consensus regarding treatment of these infants, the postnatal approach toward fetal renal pelvis enlargement remains controversial. The aim of this prospective study is to demonstrate the postnatal investigation, treatment, and outcome of infants with prenatally diagnosed hydronephrosis. Infants whose antenatal ultrasound scan showed a fetal renal pelvis of 5 mm or greater were investigated postnatally using ultrasound (US) and voiding cystourethrography. When indicated, isotope studies and intravenous urograms were also performed. We followed prospectively neonates with antenatally diagnosed hydronephrosis and recommended management guidelines on the basis of our findings. In 156 neonates (193 kidney units) that were found to have hydronephrosis, the average gestational age at which the diagnosis was made was 32.94+/-5.10 weeks. The mean duration of postnatal follow-up was 26.3+/-13.56 months (range 3-60 months). The mean APPD of the fetal renal pelvis was 10.35+/-3.24 mm (5-9 mm in 84 kidneys, 10-14 mm in 96 kidneys and > or =15 mm in 13 kidneys). Of the 193 kidney units, 145 units were found to be pathological. The most common detected underlying abnormalities were ureteropelvic junction obstruction (in 91 kidneys; 62.7%) and vesicoureteral reflux (in 24 kidneys; 16.6%). Postnatally, 23 (45%) of 51 patients whose first US was normal were diagnosed postnatally as having urinary tract abnormality. There was a negative correlation between APPD and the rate of spontaneous resolution and positive correlation between APPD and the rate of surgery (P<0.01). In conclusion, because it is not possible to determine an upper limit of normal for the antenatal renal pelvis, any baby with AH should not be considered clinically insignificant. Infants with antenatal renal pelvis measurements > or =5 mm should be investigated postnatally. A normal postnatal ultrasound scan does not preclude the presence of urinary tract abnormality.

Mild Fetal Renal Pelvis Dilatation—Much Ado About Nothing?

“…We would like to have seen information on changes in fetal RP size during the pregnancy, but reporting was inconsistent, and some studies actually excluded fetuses in whom RPD resolved before birth, which biases their results toward worse outcomes (23,24,26 -28), and few mentioned details such as calyceal dilation, which has been reported to be useful indicators of poorer prognosis (8). Timing of initial postnatal ultrasound may also be critical as babies become relatively dehydrated and oliguric for the first 48 h postnatally (39), but several studies did not mention excluding measurements during this period (18,29,30,33). Differences in measurement and interpretation of outcomes also varied.…”

“…Five hundred and six potentially relevant studies were identified, of which 18 met the inclusion criteria (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34). Two studies reported overlapping patient cohorts but different outcomes (27,28).…”

“…The earliest reported fetal ultrasound was at 14 wk of gestation (21). Most studies reported that postnatal scans were not performed within 2 d after birth (17,20,22,23,(27)(28)(29)(30)(31), which may be important because newborns are initially oliguric and false-negative results are common at this time: 4 studies did not specify the earliest age at postnatal ultrasound assessment (18,29,30,33).…”

Postnatal follow-up of antenatal hydronephrosis: a health-care challenge

“…Many investigators, however, have not mentioned any loss of patients in their ANH programs. [4][5]7,10,14,[19][20] In one-fourth of cases, our MFM specialists recommended follow-up after birth with their pediatrician. As suggested by our data, half of these infants were deemed to be healthy and no postnatal renal US or other consultations were done.…”

Long-Term outcome of multicystic dysplastic kidneys: A single center experience.

“…Patients were evaluated based on physical examination findings, blood pressure measurements, results of urinalysis and urine culture monthly in the first six months of life, once every 3 months in the second six months, twice yearly between the ages 1 and 3 and then annually (6) . Hypertension was defined as systolic and diastolic blood pressure >95 th percentile for gender, age and height measured on three occasions.…”