The impact of fetal renal pelvic diameter on postnatal outcome
PRENATAL DIAGNOSIS Prenat Diagn 2004; 24: 591–595. Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/pd.899 The impact of fetal renal pelvic diameter on postnatal outcome Ulrike John1*, Christiane K¨ahler2, Sven Schulz1, Hans Joachim Mentzel3, Susanna Vogt3 and Joachim Misselwitz1 1Division of Pediatric Nephrology, University Children’s Hospital, Jena, Germany
2Department of Obstetrics and Gynaecology, Jena, Germany
3Institute of Diagnostic and Interventional Radiology Friedrich Schiller University, Jena, GermanyObjectives To determine thresholds for the fetal renal pelvic anterior–posterior diameter (APD) predicting
postnatal clinically relevant pelvicaliceal dilatation. Methods One hundred and forty-eight infants whose prenatal sonography had identified an isolated uni- or
bilateral fetal APD of ≥4 mm before 33 and/or ≥7 mm after 33 weeks’ gestational age were investigated
postnatally. On the basis of postnatal ultrasound examination, these infants were grouped according to the
Society for Fetal Urology Grading System: no pelvic dilatation (n = 38); only pelvic dilatation (n = 59);
pelvicaliceal dilatation (n = 33); pelvicaliceal and ureter dilatation (n = 18). Results Fetal pyelectasis of 7 mm was 89.3% sensitive and 78.9% specific <33 weeks, and ≥33 weeks
pyelectasis of 10 mm was 88.4% and 78.6% in predicting subsequent postnatal pelvicaliectasis, respectively.
Using a threshold of 4 mm <33 weeks and 7 mm ≥33 weeks yielded a sensitivity of 100% and a specificity
of 18.7% and 47.8%, respectively. The median APD (range) at ≥33 weeks was 19 mm (9–36 mm) in patients
requiring surgery and 13 mm (7–21 mm) in conservatively treated patients (p = 0.001). Thirteen of fourteen
patients with APD ≥19 mm underwent surgery. Conclusion Women with ultrasonographically detected prenatal fetal pelvic dilatation of ≥4 mm before
33 weeks and of ≥7 mm from 33 weeks onwards of gestation should have repeated prenatal ultrasound
scans and a detailed postnatal evaluation. The dilatations of an APD >4 mm before 33 weeks, which have
disappeared at the post-33-week scan need no further investigation in the postnatal period. Copyright 2004
KEY WORDS: fetal; renal; pyelectasis; ultrasonography; prenatal diagnosis
investigation (Anderson et al., 1995; Corteville et al.,
1991; Fasolato et al., 1998; Mouriquand et al., 1999;
Fetal pyelectasis is the most common prenatal diag-
Kent et al., 2000, Siemens et al., 1998). The outcome
nosed malformation with 0.2 to 1% of all pregnancies
and proper management of fetal hydronephrosis are not
(Thomas, 1990). Fetal renal pelvic dilatation is com-
defined sufficiently. The prognosis of obstructive uri-
monly observed during prenatal ultrasound examina-
nary tract anomalies is variable and depends on several
tions, but its clinical significance remains unclear. The
conditions: the gestational age at diagnosis, the local-
number of otherwise healthy fetuses that are diagnosed
ization of the stenosis, the bilateral or unilateral alter-
with this condition is on the increase, with the growing
ation of the kidneys, and the amount of amniotic fluid
use of ultrasound in obstetrics. As a result, more infants
as an indicator for renal function. Spontaneous reso-
with this history are being presented to pediatricians,
lution has been described as well as the progression
nephrologists and urologists. The most common uri-
into a severe obstruction with development of cystic
nary tract abnormality is a nonspecific hydronephrosis.
renal dysplasia and the loss of renal function (Sohn
Almost half of all prenatally diagnosed hydronephroses
and Tercanli, 2003). In general terms, the pediatrician’s
that are found after investigation are an isolated upper-
goal concerning newborns diagnosed with pyelectasis
tract dilatation. This population has posed the greatest
or hydronephrosis should be to strike the right balance
challenge in prospectively determining which of these
between excessive medical intervention (long, costly and
asymptomatic children have an obstruction that would
often useless follow-ups, which arouse unjustified and/or
benefit from surgery, as opposed to a simple dilatation
disproportional parental anxiety) and sufficient interven-
that may be inconsequential to their well-being (Dhillon,
tion to diagnose potentially dangerous conditions (Fanos
1998). Various cut-off values for dilatation of the fetal
renal pelvis are being described as requiring postnatal
This study was performed in order to assess the clini-
cal impact of prenatal ultrasonographically detected fetal
renal pelvic dilatation and to determine thresholds for the
*Correspondence to: Ulrike John, Division of Pediatric Nephrol-
ogy, University Children’s Hospital, Kochstrasse 2, 07740 Jena,
fetal renal anterior–posterior diameter (APD) predicting
Germany. E-mail: [email protected]
postnatal clinically relevant pelvicaliceal dilatations.
Copyright 2004 John Wiley & Sons, Ltd.
was performed to evaluate function and drainage. An
obstructive washout pattern was defined as the half-time
One hundred and ninety-six pregnant women were
radiotracer washout longer than 20 min (O‘Reilly et al.,
referred to our university hospital (from January 1990 to
December 1999) because of a suspected renal anomaly,
An indication for surgery was given: (1) if the
identified during a prior external ultrasonographic exam-
hydronephrotic kidney showed decreased differential
ination. They were to be examined using the espe-
function (<40%) and an obstructive type of the washout
cially fine diagnostics permitted by ultrasonography uti-
curve in diuresis renography; (2) in cases with normal
lizing a 3.75 MHz transducer (Toshiba SSA 270 A).
differential function but an obstructive type of drainage
All 196 infants had postnatal nephro-urological exam-
curve at least in two investigations in combination with
ination. One hundred and forty-eight patients were
an unchanged or increased pelvicaliceal dilatation.
included in this study with: (1) prenatal isolated uni-
or bilateral renal pelvic dilatation defined as fol-
Statistical analysis <33 weeks of gestation anterior–posterior diam-
eter (APD) ≥4 mm and ≥33 weeks of gestation APD
≥7 mm; (2) postnatal ultrasound diagnosis for each kid-
Multiple thresholds were analyzed for the fetal renal
ney according to the Society for Fetal Urology grad-
pelvic APD and correlated with infant outcome. The goal
ing system (Fernbach et al., 1993) at the age of three
was to choose the threshold with the highest sensitiv-
months: (a) normal (NORMAL): without any pelvic
ity for predicting congenital pelvicaliceal dilatation. The
dilatation, (b) pyelectasis (PYECT): without caliceal
receiver-operating characteristic (ROC) plots of various
dilatation or when a few but not all calices are identified,
fetal APD thresholds were created from sensitivity ver-
(c) pelvicaliceal dilatation (PCD), (d) dilated ureter and
sus 1-specificity calculated from cross-tables to discrim-
inate between kidneys with and without a subsequent
In our management, micturating cystourethrography
postnatal relevant pelvicaliceal dilatation (kidneys with
(MCUG) is not recommended for all infants with
PCD or UPCD). The Kruskall–Wallis test was used to
prenatal pelvic dilatation. We performed MCUG only in
confirm differences between the various groups of diag-
those 55 of 152 infants with postnatal PCD or UPCD.
nosis followed by comparison in pairs (Mann Whitney
We found bilateral refluxes in four infants (two boys,
U-test). Differences were considered to be statistically
two girls; grade 3 in three kidneys, grade 4 in four and
significant at a P-value <0.05.
grade 5 in one kidney). Since this diagnosis may only be
made by virtue of the postnatal MCUG, which was not
performed in all patients of our study, these four cases
Forty-four of one hundred and ninety-six patients
with gross structural anomalies of the urinary tract were
excluded prior to entry of study analysis: duplication
From 148 infants, a fetal pelvic dilatation was diag-
(n = 11), multicystic dysplastic kidney (n = 16), poste-
nosed, which was bilateral in 72 and unilateral in 76
rior urethral valves (n = 3), and miscellaneous (n = 14).
fetuses. Postnatally, we found bilateral NORMAL kid-
A total of 433 prenatal and 502 postnatal ultrasound
neys in 38 infants. Sixty-eight infants had unilateral
investigations in 148 patients were performed at an
involvement with the diagnoses PYECT, PCD, UPCD,
average of 6.3 scans per patient. All 148 patients with
and 42 bilateral combined with corresponding diagnoses.
296 renal units had at least one ultrasound examination
Finally, for further analysis of renal APD, we consid-
before and/or after 33 weeks of gestation. Measurement
ered all 296 kidneys (148 patients) including postnatal
of the APD only before 33 weeks of gestation was
diagnoses: NORMAL: n = 144; PYECT: n = 98; PCD:
performed in 35, only after 33 weeks of gestation in
n = 33 and UPCD: n = 21.
51, and in both time periods in 62 patients. In our
retrospective study, we did not evaluate the reasons for
APD in prenatal ultrasound scans
no further renal scan in pregnancy for the 35 subjects
who had only one renal scan. Finally, 194 kidneys were
examined before 33 weeks’ gestation and 226 kidneys
The median (range) APDs of the prenatal scans below
≥33 weeks’ gestation, respectively. Prenatal ultrasound
33 weeks of gestational age found in the various groups
was done at a median (min; max) fetal patient age of
23 weeks of gestation (min 18; max 32) in the group
(1.0–9.0), 6.6 mm (3.5–16.0), 10.8 mm (6.0–28.8) and
<33 weeks of gestation and 37 weeks (min 33; max 41)
7.1 mm (4.0–13.0), respectively. The corresponding val-
in the group of over 33 weeks of gestation. After birth,
ues of APDs ≥33 weeks of gestational age were 5.0 mm
all 148 infants were followed-up, performing at least one
(2.0–15.0), 9.0 mm (2.3–18.0), 18.0 mm (7.1–36.0)
ultrasound examination until three months of life using
and 13.8 mm (8.0–32.0), respectively.
a 5 to 7 MHz transducer (Acuson 128 XP-10). Median
At 18 to 32 weeks’ gestation, significant differences
follow-up time was 1.14 years (min 0.01; max 9.1) in
of the fetal renal pelvic APD of NORMAL kidneys
versus PYECT, PCD and UPCD were found by com-
In all infants with PCD or UPCD, at least one 99m-
parison in pairs (p < 0.001), although the APDs of kid-
TcMAG 3 diuresis renography with furosemide washout
neys with UPCD compared with PCD or PYECT did
Copyright 2004 John Wiley & Sons, Ltd. Prenat Diagn 2004; 24: 591–595.
THE IMPACT OF FETAL RENAL PELVIC DIAMETER
Figure 1—Median renal APDs (mm) of the prenatal scan ≥33 weeks’
gestation (n = 226 kidneys) found in the various groups with postnatal
Figure 2—(a) Receiver operator characteristic curves illustrating the
not show significant differences (p = 0.054, p = 0.240,
ability of the fetal renal pelvic APD (mm) <33 weeks’ gestation to
distinguish between kidneys with (n = 28) and without (n = 166)
At the time period 33 to 41 weeks’ gestation, the fetal
a subsequent postnatal relevant pelvicaliceal dilatation. (b) Receiver
renal pelvic APDs differed significantly for the various
operator characteristic curves illustrating the ability of the fetal
kidney diagnoses: NORMAL, PYECT, PCD and UPCD
renal pelvic APD (mm) ≥33 weeks’ gestation to distinguish between
kidneys with (n = 43) and without (n = 182) a subsequent postnatal
(p < 0.0001). However, no significant difference of the
renal APD between PCD and UPCD (p = 0.242) was
found (Figure 1). Of 62 infants who did have more than
of thirty-three kidneys with PCD and 8 of 21 kidneys
one scan before and after 33 weeks, eight had an APD
with UPCD required unilateral surgical treatment. Alto-
below 7 mm in both kidneys at the post-33-week scan.
gether, 25 of 148 children (17%) had surgical treatment.
Moreover, they had no renal dilatation in the scan after
In order to test the differences of the renal pelvic APD
at various gestational periods between surgically and
ROC analysis predicting subsequent
conservatively treated children, only the children with
postnatal diagnosed pelvicaliceal dilatation (PCD and
postnatal pelvicaliceal dilatation
At <33 weeks’ gestation, the median APDs (range)
Using a threshold of 7 mm, it was found that fetal
<33 weeks’ gestation of conservatively treated patients
renal pelvic dilatation was 89.3% sensitive and 78.9%
(n = 17) and surgically treated patients (n = 17) were
specific at <33 weeks (Figure 2a). The best correspon-
10.3 mm (4–19) and 11.0 mm (7–23), respectively
dence between sensitivity and specificity ≥33 weeks
showed the threshold of 10-mm renal pelvic dilatation
At 33 to 41 weeks’ gestation, the median APDs
with 88.4% and 78.6% in predicting subsequent pelvi-
(range) in conservatively treated (n = 16) and in patients
caliceal dilatation, respectively (Figure 2b). This was
requiring surgery (n = 23) were 13.3 mm (7–21) and
accomplished by using a receiver-operating characteris-
19.0 mm (9–36), respectively (p = 0.001) (Figure 3).
tic curve categorizing the prenatal sonograms into gesta-
Thirteen of fourteen patients who had an APD
tional periods and varying the threshold of APD in each
≥19 mm at the 33 to 40 weeks’ gestational period
period. Using a threshold of 4 mm (<33 weeks) and
underwent surgical intervention postnatally.
7 mm (≥33 weeks) yielded a sensitivity of 100% and a
specificity of 18.7 and 47.8%, respectively (Figure 2a,b). APD in surgically and conservatively treated patients
Prenatal ultrasonography has identified a large popu-
lation of fetuses with a urinary tract abnormality that
All infants with only uni- or bilateral NORMAL and
is most commonly a nonspecific upper-tract dilatation
PYECT (n = 97) were treated conservatively. Seventeen
with or without ureteric dilatation. Ultrasonographic
Copyright 2004 John Wiley & Sons, Ltd. Prenat Diagn 2004; 24: 591–595.
10 mm ≥33 weeks’ gestation yielded the highest com-
bined sensitivity and specificity (89 and 78%, respec-
tively) for predicting a subsequent pyelocaliectasis. In
order to identify all ‘at risk’ fetuses, a lower fetal renal
APD of ≥4 mm before 33 weeks and ≥7 mm ≥33
weeks would be required. The specificity, however, asso-
ciated with these thresholds would be 18.7 and 47.8%,
respectively. An APD of ≥4 mm at the first trimester is
the most commonly used cut-off to denote hydronephro-
sis (Stocks et al., 1996; Sairam et al., 2001; Adra et al.,
1995; Kitagawa et al., 1998). A recent study revealed
that the third trimester anterior–posterior renal pelvis
diameter of ≥7 mm was the best ultrasound criterion
to predict postnatal uropathies (Ismaili et al., 2003).
Ouzounian et al. (1996) have demonstrated that fetal
pyelectasis of 8 mm produced the best combination of
sensitivity and specificity, 91 and 72% respectively.
In order to achieve 100% sensitivity, they recommend
postnatal renal ultrasonography for patients with fetal
pyelectasis of ≥5 mm at any gestational age. Mandell
et al. (1991) found that the degree of dilatation did
not correlate well with postnatal findings. They there-
fore recommended clinically significant thresholds for
pyelectasis of 5 mm between 15 and 20 weeks, 8 mm
between 20 and 30 weeks and >10 mm after 30 weeks.
By using a cut-off value of 10 mm as recommended by
other authors (Sairam et al., 2001), 11% of the neonates
Figure 3—Median fetal renal pelvic APD (mm) in patients <33 and
of our study would not have been recognized. The false-
≥33 weeks’ gestation with surgery versus conservative therapy in
positive rate declines with advancing gestational age. A
critical note to these high demands for security is the
fact that they may lead to unwarranted parental concern
identification in utero of fetuses at risk of subsequent
as well as expensive postnatal diagnostic studies. In 8
pelvicaliceal dilatation can minimize diagnostic delays
of 62 infants (13%), the fetal renal APD had resolved
and potentially reduce morbidity (Ouzounian et al.,
<7 mm at the post-33-week scan and showed no dilata-
1996). Our approach was to predict such fetuses that will
tion postnatally. Our findings support the results of Kent
suffer from significant renal pathology to be identified
et al. (2000) that the fetus with a normal repeat ultra-
sound at 28 to 34 weeks would not require a postnatal
The fetal renal APD was analyzed before and after
33 weeks of gestation. The APD of the fetuses with
For our application, the important practical criterion
subsequent neonatal PCD was different from those with
in prenatal ultrasonography to distinguish future abnor-
no dilatation or pyelectasia at any gestational period.
mal postnatal ultrasound scans for the diagnostics of
Whereas the fetal renal APD of fetuses with future
PCD and UPCD include pelvic, caliceal and/or ureteral
neonatal PYECT and UPCD did not differ in the early
dilatation and changing dilatation during the examina-
period below 33 weeks of gestational age, the distinction
tion. Measurement of the fetal renal APD has emerged as
after this time was significant (Figure 1). The fetal renal
a sensitive and accurate technique for the 100% identifi-
APD showed no difference between PCD and UPCD
cation of children with possible fetal renal abnormalities.
at any prenatal period. Therefore, the crucial role of
Surgical rates from 7 to 40% in children with pre-
the ureter distinguishing PCD from UPCD will be clear
natal hydronephrosis have been described (Gunn et al.
in the portrayal using ultrasound scan as mentioned by
1995; Corteville et al., 1991). The largest prospective
other authors (Stocks et al., 1996; Wilson et al., 1997;
study of Sairam et al. (2001) in an unselected routine
Langer et al., 1996; Anderson et al., 1997; McIlroy
obstetric population of 11 465 children revealed 11 of
et al., 2000; McLellan et al., 2002).
75 fetuses (15%) with hydronephrosis who underwent
The measurement of the anterior–posterior renal
postnatal surgery. In our study, 25 of 148 children (17%)
pelvic diameter by ultrasonography has proved to be
underwent postnatal surgery. All of them had PCD or
the most useful tool for identifying the group that needs
UPCD. None of the children with simple pelvic dilata-
close follow-up from those patients who need minimal
tion required surgery. The fetal renal APD of postna-
imaging (Dhillon, 1998). There is, however, no agreed
tally surgically treated patients compared with conserva-
definition of ‘significant’ prenatal renal pelvic dilatation,
tively followed-up patients showed no difference below
which warrants further postnatal investigations (Morin
33 weeks’ gestation. After this time, however, the dif-
et al., 1996; Anderson et al., 1995; Ismaili et al., 2003).
ference was highly significant. Our study shows that
Results of our study indicate that a fetal pyelectasis
fetuses with APD ≥19 mm after 33 weeks’ gestation
threshold of 7 mm before 33 weeks’ gestation and of
have a significant risk of postnatal surgery. The study
Copyright 2004 John Wiley & Sons, Ltd. Prenat Diagn 2004; 24: 591–595.
THE IMPACT OF FETAL RENAL PELVIC DIAMETER
group of Gotoh et al. (1998) found in their population,
Fasolato V, Poloniato A, Bianchi C, et al. 1998. Feto-neonatal
6/36 fetuses requiring neonatal surgery. The mean ante-
ultrasonography to detect renal abnormalities: evaluation of 1-year
rior–posterior diameter in those who did not require
screening program. Am J Perinatol 15: 161–164.
Fernbach SK, Maizels M, Conway JJ. 1993. Ultrasound grading of
surgery at infancy (11 ± 6 mm) was significantly less
hydronephrosis: introduction to the system used by the Society for
than those requiring surgery (30 ± 14 mm, p < 0.01). In
fetal urology. Pediatr Radiol 23: 478–480.
accordance with our results, Gotoh et al. (1998) recom-
Gotoh H, Masuzaki H, Fukuda H, Yoshimura S, Ishimaru T. 1998.
mended surgery if diameters at 30 to 40 weeks’ gestation
Detection and assessment of pyelectasis in the fetus: relationship to
postnatal renal function. Obstet Gynecol 92: 226–231.
Gunn TR, Mora D, Pease P. 1995. Antenatal diagnosis of urinary
The discussions continue about imaging modalities
tract abnormalities by ultrasonography after 28 weeks’ gestation:
and indication for surgery to be modified and improved
incidence and outcome. Am J Obstet Gynecol 171: 479–486.
in the hope of identifying a parameter that could
Ismaili K, Hall M, Donner C, Thomas D, Vermeylen D, Avni FE.
prospectively identify those infants whose hydronephro-
2003. Results of systematic screening for minor degrees of fetal
renal pelvis dilatation in an unselected population. Am J Obstet
sis does represent an obstruction that could be detrimen-
Gynecol 188(1): 242–246.
Kent A, Cox D, Downey P, James SL. 2000. A study of mild
fetal pyelectasia—outcome and proposed strategy of management. Prenat Diagn 20: 206–209.
Kitagawa H, Pringle KC, Stone P, Flower J, Murakami N, Robin-
son R. 1998. Postnatal follow-up of hydronephrosis detected by pre-
natal ultrasound: the natural history. Fetal Diagn Ther 13: 19–25.
In addition to providing guidelines for diagnosis of
Langer B, Simeoni U, Montoya Y, Casanova R, Schlaeder G. 1996.
Antenatal diagnosis of upper urinary tract dilatation by
fetal renal pelvic dilatation, this study also gives valu-
ultrasonography. Fetal Diagn Ther 11: 191–198.
able information for the counsel of future parents. We
Mandell J, Blyth BR, Peters CA, Retik AB, Estroff JA, Benacar-
recommend that ultrasonographically detected prenatal
eff BR. 1991. Structural genitourinary defects detected in utero.
fetal renal pelvic dilatation of ≥4 mm before 33 weeks
Radiology 178: 193–196.
McIlroy PJ, Abbott GD, Anderson NG, Turner JG, Mogridge N,
and ≥7 mm from 33 weeks of gestation should entail a
Wells J. 2000. Outcome of primary vesicoureteric reflux detected
postnatal follow-up ultrasound examination. In cases of
following fetal renal pelvic dilatation. J Paediatr Child Health 36:
fetal renal pelvic dilatation before 33 weeks’ gestation,
a repeated ultrasound scan after 33 weeks’ gestation
McLellan DL, Retik AB, Bauer SB, et al. 2002. Rate and predictors
is mandatory in order to detect dynamic and possible
of spontaneous resolution of prenatally diagnosed primary
nonrefluxing megaureter. J Urol 168(5): 2177–2180.
progress. A detailed postnatal evaluation including a
Morin L, Cendron M, Crombleholme TM, Garmel SH, Klauber GT,
voiding cystourethrography and a renal nuclear scan is
D‘Alton ME. 1996. Minimal hydronephrosis in the fetus: clinical
required if pelvicaliceal dilatation and/or ureter is con-
significance and implications for management. J Urol 155:
firmed in neonates. Fetuses with a pelvic dilatation of
Mouriquand PDE, Troisfonraines E, Wilcox DT. 1999. Antenatal and
more than 19-mm APD have a significant chance of
perinatal uro-nephrology : current questions and dilemmas. Pediatr
requiring surgery. The dilatation of an APD >4 mm
Nephrol 13: 938–944.
before 33 weeks, which had resolved at the post-33-
O’Reilly P, Aurell M, Britton K, Kletter K, Rosenthal L, Testa T.
week scan needs no further investigation in the postnatal
1996. Consensus on diuresis renography for investigating the
dilated upper urinary tract. Radionuclides in Nephrourology Group.
Consensus Committee on Diuresis Renography. J Nucl Med 37(11):
Ouzounian JG, Castro ME, Fresquez M, Al-Sulyman OM, Kovacs
BW. 1996. Prognostic significance of antenattally detected fetal
pyelectasis. Ultrasound Obstet Gynecol 7: 424–428.
Sairam S, al-Habib A, Sasson S, Thilaganathan B. 2001. Natural
Adra AM, Mejides AA, Dennaoui MS, Beydoun SN. 1995. Fetal
history of fetal hydronephrosis diagnosed on mid-trimester
pyelectasis: is it always physiologic? Am J Obstet Gynecol 173:
ultrasound. Ultrasound Obstet Gynecol 17: 191–196.
Siemens RD, Prouse KA, MacNeily AE, Sauerbrei EE. 1998. Ante-
Anderson N, Clautice-Engle T, Allan R, Abbott G, Wells E. 1995.
natal hydronephrosis: thresholds of renal pelvic diameter to predict
Detection of obstructive uropathy in the fetus: predictive value
insignificant postnatal pelviectasis. Tech Urol 4: 198–201.
of sonographic measurements of renal pelvic diameter at various
Sohn C, Tercanli S (eds). 2003. Ultraschall in Gyn¨akologie und
gestational ages. AJR 164: 719–723.
Geburtshilfe. Thieme Verlag Stuttgart: New York; 245–277.
Anderson N, Abbott GD, Mogridge N, Allan RB, Maling TM,
Stocks A, Douglas R, Frentzen B, Richard G. 1996. Correlation of
Wells JE. 1997. Versicoureteric reflux in the newborn: relationship
prenatal renal pelvic anteroposterior diameter with outcome in
to fetal renal pelvic diameter. Pediatr Nephrol 11: 610–616.
infancy. J Urol 155: 1050–1052.
Corteville JE, Gray DL, Crane JP. 1991. Congenital hydronephrosis:
Thomas DFM. 1990. Fetal uropathy. Br J Urol 66: 225–231.
correlation of fetal ultrasonographic findings with infant outcome.
Wilson RD, Lynch S, Lessoway VA. 1997. Fetal pyelectasis:
Am J Obstet Gynecol 165(2): 384–388.
comparison of postnatal renal pathology with unilateral and bilateral
Dhillon HK. 1998. Prenatally diagnosed hydronephrosis: the Great
pyelectasis. Prenat Diagn 17: 451–445.
Ormond Street experience. Brit J Urol 81(2): 39–44.
Fanos V, Agostiniani R, Cataldi L. 2000. Pyelectasis and hydrone-
phrosis in the newborn and infant. Acta Pædiatr 89: 900–904.
Copyright 2004 John Wiley & Sons, Ltd. Prenat Diagn 2004; 24: 591–595.
Ingredients: Contains a special, high-quality grease with graphite, copper flake, aluminum powder and zinc oxide. NEVER SEEZ ® Shelf Life: Never-Seez® Regular Grade does not deteriorate with age when stored unopened at temperatures below 120°F (49°C). Anti-Seize & Lubricating Compound Quality and performance are guaranteed for five years from the date of manufacture on unopen
Network Working Group ISO Request for Comments: 905 April 1984 ISO Transport Protocol Specification ISO DP 8073 This document is distributed as an RFC for information only. It does not specify a standard for the ARPA-Internet. 1) RFC 892 is an older version of the ISO Transport Protocol Specification. Therefore this RFC should be assumed to supercede RFC 892. 2) This document has been prepa