FETUS URINARY SYSTEM

1. Case of Bladder outlet
obstruction-PUV
Dr Kruti Savalia

2. Case
• A female patient Mrs X aged 28 years was reffered to us for second
opinion for hydronephrosis on 22/06/2022

3. 1 st scan-GA 24.1 week
• It was diagnosed as bilateral gross
hydronephrosis with peripheral
calyceleal dilatation-UTD 2/3
• Both kidneys enlarged size 35/37 mm

4. • Bilateral ureter dilated and showing
peristalsis
• UB wall hypertrophied
• Thickness 4 mm

5. • Persistently enlarged urinary bladder size 30 mm
Key hole sign seen

6. Advice
• Non lethal anomaly with guarded prognosis
• Other parameters were normal including AFI
• Paediatric urosurgeon reference advised
• Follow up after 4 weeks advised
• Patient counselled

7. Second scan after 4 weeks at GA 28.5 days
• Bilateral gross hydronephrosis with peripheral calyceleal dilatation-UTD 2/3
• Both kidneys enlarged size 50/42 mm

8. • UB wall hypertrophied-thickness
was 4.1 mm
• Bilateral ureter dilated

9. • Other parameters were normal including AFI
• Diagnosis and advise were same as previous scan

10. 3rd scan after 4 weeks at GA 33.5 days
• Bilateral gross hydronephrosis with
peripheral calyceal dilatation
• Both kidneys enlarged- 57/57 mm
• UB wall hypertrophied
• Thickness was 5.5 mm

11. • Other parameters were normal.
• Afi was reduced-oligohydramnios
• Diagnosis and advise were same as previous scan

12. Diagnosis
• All these findings suggestive of LUTO-Lower urinary track obstruction
due to BOO-bladder outlet obstruction
• Probably due to posterior urethral valve
• Comes under UTD 2/3

13. Bladder outlet obstruction
• Most common cause is PUV-posterior urethral valve
• PUVs are membranes within posteror aspect of urethra
• Affects male fetuses
• Represent with-enlarged bladder and urethra-keyhole sign
• Ureters and renal pelvis also dilated
• With worsening-bladder wall becomes hypertrophied with
trabeculations
• Renal parenchymal destruction and dysplasia results from back
pressure-atrophic changes

14. • Severe cases also present with oligohydramnios, peripheral urinomas
and urinary ascites
• Phenotypic changes in newborn-potter facies and contracture of
extremities
• Pulmonary hypoplasia
• Poor prognosis-hyperechogenic cystic renal parenchyma and renal
cortical cysts
• Electrolyte measurement in fetal urine-transabdominal
vesicocentesis-controversial role

15. • Vesico amniotic shunting to divert urine to amniotic cavity from
obstructed bladder-long term results not convincing
• PLUTO-Percutaneous shunting in lower urinary tract obstruction-
stopped now-poor recruitment
• Fetoscopic placement of trans urethral stent-under trial

17. Causes of Enlarged Bladder
• Posterior urethral valves
• Anterior urethral valves/Congenital megalourethra
• Urethral atresia
• Megacystitis microcolon intestinal hypoperistalsis syndrome
• Cloacal malformation
• Megacystitis/megaureter
• Prolapsed ureterocele/Vesicoureter reflux

18. Differential Diagnosis
• Congenital megalourethra/Anterior urethral valves-dilated elongated
penile urethra-male fetus
• Prune Belly syndrome-USG features are similar but bladder and
urethral dilatation are not as marked-male fetus
• Transient Dilation-resolves after birth
• Congenital megacystitis/Vesicoureteral reflux/Transient BOO-
cystourethrogram distinguish it
• Duplex collecting system/Ureterocele-septum/cyst within bladder

19. • Urethral atresia-common in female-complete obstruction
• Cloacal malformation-usg features same-female fetus
• MMIHS-Mega cystitis microcolon intestinal hypoperistalsis syndrome-
common in female, small bowel obstruction, intestinal malrotation,
liquor normal or polyhydramnios, associate with cardiac defects, cleft
lip, palate, omphalocele

20. Post natal follow up
• Findings were correlated with
antenatal findings.

22. THANK YOU