1. urinary tract defects
Prof. Z. Babay

2. Urinary tract defects
Accounts for 34% of all malformations detected by ultrasound
32% of these are isolated findings
48% associated with chromosomal abnormality or other syndromes
Pelvi calyceal dilatation occur in 87% of all cases
Only 13% of cases are isolated parenchymal disease without pelvi-calyceal dilatation
Only 25% of the cases of renal dysplasia are detected by ultrasound

3. Urinary tact defects Kidneys are visible by 12 weeks of gestation
At renal pyramids are visible
The ratio of renal to AC is always 30%
Normal ureters are not visible by ultrasound

5. Urinary tract abnormalities
Classification:
A) Parenchymal: Multi-Cystic disease
Dysplasia (Potters)
Renal agenesis
B) Obstructive

6. Urinary tract abnormalities
Incidence:
Bilateral in 1: 5000 births
Unilateral in 1:2000 births
Could be isolated or part of a syndrome or chromosomal abnormality
If part of a syndrome----the risk of recurrence is 3%
If one parent is has unilateral renal agenesis---risk is 15%

7. Renal agenesis (cont.)
Usually associated with oligo- or anhydramnios and empty bladder
If unilateral------normal AFI-----good prognosis
If bilateral---lethal-----pulmonary hypoplasia
Failure to visualize renal arteries by color Doppler can help in the diagnosis

10. Infantile polycystic kidney (Potter type I)
Found in 1:30,000 births
Autosomal recessive
Carried on the short arm of chromosome 6
Diagnosis by PGD or ultrasound

11. Potter I (cont.) By ultrasound:
Markedly enlarged kidneys, numerous cortical cysts, dilated collecting ducts
Oligohydramnios
Loss of cortico-medullary junction
Usually seen at 24 weeks
Usually lethal
Can accompany hepatic cysts or fibrosis

13. Multicystic Dysplastic kidneys(PottersII)
Occur in 1: 1000 births
Usually sporadic
Result from obstruction at early fetal life
Could be Associated with chromosomal abnormalities, genetic syndromes or cardiac defects in 50% of cases
In 15% of cases there is contra lateral renal agenesis

16. Potters II (cont.) By ultrasound:
Irregular cysts of variable size with intervening hyper-echoic stroma
It can be unilateral, bilateral or segmental
If bilateral----oligohydramnios--- absent bladder---lethal
If unilateral--- good prognosis

18. Adult polycystic kidney disease (APKD)
Autosomal dominant
1:1000 of APKD carry mutant gene
Usually asymptomatic until 3rd decade of life
Ultrasound: enlarged hyper-echoic kidneys with or without multiple cysts
There is accentuation of cortico-medullary junction

19. Renal Dysplasia (potters III)
Markedly enlarged kidneys with cysts of variable size
Both kidneys are equally enlarged
1/3 have cysts in the liver, pancreas, spleen or lungs
1/5 have cerebral aneurysm
It is the expression of adult poly-cystic kidney (autosomal dominant) and other mendelian disorders e.g. tuberous sclerosis

20. APKD (cont.) AFI is normal or slightly reduced
Prenatal diagnosis is by PGD
If one parent is affected----normal kidneys by ultrasound does not exclude the disease

22. Obstructive uropathies
If occur early in fetal life---renal hypo-plasia or dysplasia
If occur late in fetal life(2nd trimester) or intermittent--- Hydronephrosis
Dilatation of fetal urinary tract does not always mean obstruction and obstruction may not show urinary tract dilatation
Hydronephrosis associated with chromosomal abnormality in 20% of cases

23. Hydronephrosis Found in 1% of fetuses
Mild--A-P diameter of renal pelvis >4mm at weeks
A-P diameter of renal pelvis >5mm at weeks
A-P diameter of renal pelvis > 7mm at weeks
Moderate-- > A-P diameter of renal pelvis >10 mm + pelvi-calyceal dilatation

24. Hydronephrosis (cont.)
In 20%---underlying obstruction at pelvi-ureteric junction, or vesico-ureteric reflux, or posterior uretheral valve
Post-natal surgery is needed in 50% of cases

29. Assessment of fetal renal function
Ultrasound + analysis of fetal urine by urodochocentesis or pyelocentesis
Poor prognostic signs:
1)Bilateral multicystic or severely hydronephrotic kidneys with echogenic kidneys suggesting renal dysplasia
2)Oligo-or anhydramnios
3)High urinary Na,Ca,β2 micro-globulin

30. Thank you