PowerPoint

Fetal Hydronephrois
NUHS-Evanston
General Care Nursery Rotation

Case 1
• A newborn female infant is born to a G1P0
mom at 39 2/7 week by SVD. Maternal history
was significant for a gestational diabetes.
Prenatal ultrasound showed right renal
pelviectasis. Infant has urinated within 24
hours and has normal physical exam. What
treatment and/or evaluation would you
complete for the infant?

Please select the best answer
A. Ultrasound and VCUG prior to discharge
and bactrim prophylaxis
B. Ultrasound at 1 week and 6 weeks,
amoxicillin prophylaxis
C. No testing or prophylaxis
D. VCUG at 1 week

Definition
• During routine ultrasound at 18-20 weeks
gestation: Fetal or antenatal hydronephrosis
is detected in 0.5-5% of all pregnancies.
• More common in males than females
• >50% of cases are transient or phsyiologic

Society of Fetal Urology grading system
Only Grade III, IV are thought to be clinically
significant
Grade Central renal complex Renal parenchymal
thickness
0 Intact Normal
I Slight splitting of pelvis Normal
II Evident splitting of
pelvis and calices
III Wide splitting of pelvis
and calices
IV Further splitting of
pelvis and calices
Normal
Normal
reduced

Degree of hydronephrosis:
measurement of renal pelvic diameter
• Mild: unilateral or bilateral renal pelvic
diameter (RPD) 7-9 mm after 34 weeks
gestation (wg)
• Moderate: RPD 10-14 mm after 34 wg
• Severe: RPD >=15 mm after 34 wg

Causes of Neonatal Hydronephrosis
• Transient hydronephrosis 48%
• Physiologic hydronephrosis 15%
• Ureteropelvic junction obstruction 11%
• Vesicoureteral reflux 9%
• Uterovesical junction obstruction 4%
• Multicystic dysplastic kidney 2%
• Posterior Urethral Valve 1%
• Ureterocele 2%
• Dilation of one moiety of duplex kidney

Postnatal evaluation
• Complete physical exam
– Prune belly ( deficient abdominal wall musculature
with undescended testes
– Abdominal mass
– Distended bladder
• Ultrasound at 1 week and 6 weeks
– Delay the first US to avoid false negative results
when the baby is oliguric
• Amoxicillin prophylaxis until reflux ruled out

Immediate evaluation
• Bladder outlet obstruction or severe bilateral
hydronephrosis
• Obtain US and VCUG within 48 hours of birth

Amoxicillin
prophylaxis
Algorithm
( BJU International(2002). 89,149-156)
Ultrasound at 1 and 6 weeks
Hydronephrosis
Reflux
DMSA
RPD > 5mm
VCUG
No reflux,
persistent
hydronephrosis
RPD > 10 mm
Renogram to rule
out obstruction
Normal
Stop antibioitcs
Repeat US in 1
year

Uteropelvic junction obstruction
• 1 in 2000 children
• Male to female 3:1
• Caused by intrinsic stenosis/valves, insertion
anomaly of ureter
• Hydronephrosis without ureteric dilatation and
normal bladder and amniotic fluid
• Diagnosed with renogram
• Surgery if loss of renal function

Vesicourethral reflux
• May exist with normal postnatal renal
ultrasound
• Diagnosed with VCUG
• Treatment with prophylaxis antibiotics
• 65% will resolve within 2 yr without surgery

Vesicoureter junction obstruction
megaureter
• Male to female 4:1
• Bilateral 25%
• Left > right
• Diagnosis with dilated ureter > 7 mm and
renal pelvis with variable parenchymal
atrophy

Posterior Urethral Valves
• 1 in 8000 babies
• Progressive bilateral hydronephrosis
• Thick walled bladder with diverticulae and
poor emptying
• Amniotic fluid volume important prognostic
indicator
• Cath the bladder may require suprapubic
• VCUG and RUS within 48 hr
• 1/3 develop renal insufficiency

Case 2
• A newborn male infant is born to a G3P2
mom at 37 2/7 week by SVD. Maternal history
was significant for a oligohydramnios.
Prenatal ultrasound showed bilateral renal
hydronephrosis. Infant has not urinated within
24 hours and has distended bladder. What
treatment and/or evaluation would you
complete for the infant?

Please select the best answer
A. Ultrasound and VCUG prior to discharge
and bactrim prophylaxis
B. Ultrasound at 1 week and 6 weeks,
amoxicillin prophylaxis
C. No testing or prophylaxis
D. US, Insert bladder catheter, VCUG, consult
urology

References
• Belarmino, Kogan. Management of neonatal
hydronephrosis. Early Human Development (2006)
82,9-14.
• Woodward, Frank. Postnatal management of
antenatal hydronephrosis. BJU International (2002)
89, 149-156.
• Nationwide Children’s Hospital practice tool: Prenatal
Hydronephrosis.
• Intermountainhealthcare.org Care Process Model :
Postnatal assessment and Management of
Hydronephrosis.