1. ANTENATAL HYDRONEPHROSIS
HASAN FARSI

2. What would you do if you have:
32-week fetus with normal amniotic fluid and suspected ureteropelvic junction.
36-week fetus with suspected posterior urethral valves without oligohydramnios.
23-week fetus with suspected PUV and oligohydramnios with bladder electrolytes suggestive of good renal function.

3. Amniotic Fluid
Lungs are correctly formed only in the presence of sufficient amniotic fluid
Transudate of maternal plasma
Diffusion across fetal skin
Fetal urine is 1st produced by the end of 9th week
Concentration ability by 12-14th week
After 18th week all amniotic fluid is fetal urine
UCNA Feb. 1995;21-30

4. Structural Abnormalities & Antenatal US
Detection of renal abnormalities with antenatal ultrasonography 1st reported in the 70s.
Most renal abnormalities are detected at 18–20 weeks of gestation 1%
50% CNS
20% GU
15% GI
8% Cardiopulmonary

5. ...... Continue Structural Abnormalities & Antenatal US
2-9/1000 birth
M:F=2:1
50–87% hydronephrosis
Maximum anteroposterior diameter of renal pelvis
Multicystic dysplastic kidney, autosomal recessive polycystic kidney disease, renal agenesis and dysplasia, bladder exstrophy, adrenal hyperplasia, neuroblastoma, mesoblastic nephroma and genital abnormalities

6. The Society of Fetal Urology Grading System for ANH

7. Grades of Hydronephrosis
Mild hydronephrosis:
Pelvic APD <=1.5 cm and normal calyces
Moderate hydronephrosis
Pelvic APD > 1.5 cm and caliectasis with no parenchymal atrophy
Severe hydronephrosis:
Pelvic APD > 1.5 cm, caliectasis and cortical atrophy
BJU Inter volume 85 Page 987  - May 2000

8. Grades of ANH grade I: the pelvic APD is 1 cm with normal calycesgrade
II, APD 1–1.5 cm with normal calycesgrade
III, APD > 1.5 cm with slight caliectasisgrade
IV, APD > 1.5 cm with moderate caliectasisgrade
V, APD > 1.5 cm with severe caliectasis and cortical atrophy
Grignon A, Radiology 1986; 160: 645 7

9. RPD Measurement & Incidence of ANH
18766 Atenatal scans from Bristol UK (RPD=>5mm)
ANH 0.59%
6292 Antenatal scans from Stoke-on-Trent UK (RPD >10mm)
ANH 0.65%
6810 Scans from India (RPD >10mm)
ANH 0.64
Indian Pediatrics 2001; 38:   

10. British Journal of Urology volume 81 Page 8 - April 1998
The Final Urological Diagnosis of 426 live-born Infants with Significant Prenatally Detected Uropathy
British Journal of Urology volume 81 Page 8  - April 1998

11. Post Urethral Valves: Antenatal US

12. Prognosis & Severity of ANH
Prognosis & severity of hydronephrosis: (% needed surgery or prolonged follow-up):
RPD > 20 mm, 94%
RPD 10–15 mm 50%
RPD was < 10 mm 3%
Grignon A, Filion R, Filiatrault D, et al: Radiology 1986 Sep; 160(3): 645-7
Outcome of fetal renal pelvic dilatation (Surgery or UTI):
Mild dilation 0%
Moderate dilatation 23%
Severe hydronephrosis 64%
Ultrasound Obstet Gynecol May;25(5):483-8.

13. Diagnosis & Severity of ANH
Mild hydronephrosis (RPD 5–9 mm) the most likely diagnosis is VUR
More marked hydronephrosis (RPD> 10 mm, and especially if > 15 mm) PUJ obstruction is the most common cause

14. Prognostic Factors of Fetal Hydronephrosis
Severity
Laterality
Ureteric dilatation
Renal parenchymal changes
Abnormalities of bladder size, thickness and emptying
The presence of concomitant oligohydramnios

15. Unfavorable Prognostic Factors
Prolonged oligohydramnios
Renal cortical cysts
Urinary contents:
Na =or>100mEq/L
Cl>90mEq/L
Osmolarity>210mmol
Elevated urinary B2-microglobulin
Reduced lung area & thoracic or abdominal circumference

16. Antenatal Counseling Enormous distress to parents
Communication difficulties between the relevant specialists
Limited understanding of the natural history
Many anomalies may have no long term consequence

17. Resolution of ANH
18 weeks
32 weeks

18. Fetal Intervention No intervention: Regular US
Termination of pregnancy (up to 23 weeks)
Induction of labor
Prenatal intervention
Only at an experienced institution under approved protocols

19. Intervention Male fetus Second trimester Severe hydroureteronephrosis
Bilateral
Reasonable fetal urinary indicators
Progressive oligohydramnios.

20. Prenatal Intervention for Urinary Obstruction
For most fetuses intervention is not necessary
Decompression will restore amniotic fluid---> prevent development of fetal pulmonary hypoplasia
?? Arrest or reverse renal cystic dysplastic changes

21. Vesicoamniotic Shunting:
Technique
Vesicostomy or pyelostomy
Pigtail shunt
Complications:
Shunt blockage or migration, preterm labor, urinary ascitis, chorioamnionitis, iatrogenic gastroschisis, intrauterine death
Outcome:
Perinatal survival 47%
Post renal insufficiency 87.5%

22. Prenatal Evaluation and Treatment for Fetal Lower Urinary Tract Obstruction"
The long term outcomes for shunts in fetal bladder outlet obstruction:
Etiology:
Posterior urethral valves 39%
Urethral atresia 22%
Prune Belly Syndrome 39%.
Outcome:
More than 45% had a GFR of >70ml/min
22% had renal insufficiency
33% were ultimately on dialysis
33% had a transplant
Society for Fetal Urology 35th Biannual Meeting 2005

23. Fetal Cystoscopy US guided 1.3mm fetoscope
Cannula thru maternal then fetal abdomen then fetal bladder
Laser ablation of valves
Results
9 fetuses:4 success
2 viable at birth
1 died age 4 months from bronchopneumonia and one died age 3 m from necrotizing enterocolitis

24. A survey instrument was mailed to all members of the Society for Fetal Urology.
7 case scenarios that addressed critical decision points in patients with antenatally detected genitourinary abnormalities.
A total of 112 of 188 Society for Fetal Urology members (60%) completed the survey.
J UROL Vol. 164, 1052–1056, September 2000

25. 32-week fetus with normal amniotic fluid and suspected ureteropelvic junction:
99% observation & serial US
36-week fetus with suspected posterior urethral valves without oligohydramnios:
Most respondents elected no intervention
27% induce early delivery

26. …continue
23-week fetus with suspected PUV and oligohydramnios with bladder electrolytes suggestive of good renal function:
Intervene antenatally using a vesicoamniotic shunt (71%)
Serial aspiration (7%)
Amnioinfusion (7%).

27. Conclusion
Situations that warrant antenatal intervention for a genitourinary abnormality are exceedingly low and may include:
Cases of oligohydramnios
Suspected favorable renal function
Absence of life threatening congenital abnormalities.
In cases with normal amniotic fluid antenatal intervention is not recommended regardless of the detected abnormality.

28. ……..continue Conclusion
No evidence exists demonstrating the benefit of antenatal intervention in terms of renal function and only in a select number of cases will it benefit pulmonary function.
To our knowledge no scientific data exist that demonstrate the long-term benefit of early delivery of cases with antenatally detected, genitourinary abnormalities.

29. Postnatal Investigations
Abdominal mass
Deficient abdominal wall
Undescended testes
Palpable bladder
Renal profile
US within 1 week (earlier ?? false because of the physiological oliguria)

30. When to perform US post delivery
Renal obstruction may be underestimated or missed on a renal sonogram obtained 6 days after birth. A sonogram obtained 6 weeks after birth is more specific for detecting obstruction.
AJR Am J Roentgenol Apr;164(4):963-7.

31. …..continue Postnatal Investigations
Is it unilateral or bilateral?
Is it solitary kidney?
Are there associated anomalies?
??? Prophylactic antibiotics
Hydronephrosis =obstruction

32.     Close this Window
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Table 1.  Classification of 778 neonatal scans, 92% referred with antenatal pyelectasis
Table 1.  Classification of 778 neonatal scans, 92% referred with antenatal pyelectasis
Intrauterine Resolution of ANH:- Classification of 778 neonatal scans for evaluation of ANH
Normal renal scans
592 (76%)
Persisting Pyelectasis
120 (15%)
Unilateral renal tract obstruction (pelviureteric junction 6, vesicoureteric junction 1)
7 (1%)
Miscellaneous anomalies
59 (8%)
Total
778
Australasian Radiology volume 47 Page 354  - December 2003
Normal renal scans
592 (76%)
Persisting Pyelectasis
120 (15%)
Unilateral renal tract obstruction (pelviureteric junction 6, vesicoureteric junction 1)
7 (1%)
Miscellaneous anomalies
59 (8%)
Total
778
Normal renal scans
592 (76%)
Persisting Pyelectasis
120 (15%)
Unilateral renal tract obstruction (pelviureteric junction 6, vesicoureteric junction 1)
7 (1%)
Miscellaneous anomalies
59 (8%)
Total
778
                                 
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33. Fate of ANH

34. Transient Hydronephrosis
30-50% of ANH
Etiology ??:
Insufficient maturation of UPJ
Insufficient maturation of VUJ
Increased fetal urinary output (4–6 times greater before than after delivery)
Partial or transient anatomical or functional obstructions, e.g. fetal ureteric folds

35. New Investigative Modalities for Post natal Evaluation of ANH
MR urography:
MR urography alone was found to be comparable with conventional combination studies of DRS and US or urography.
Renal dysplasia
Doppler derived renal resistive index measures (RI)
The results of this study do not support the clinical use of Doppler ultrasound studies in the diagnostic work-up of congenital hydronephrosis

36. Repeat US in 3-6m
Dudley, J A et al. Arch. Dis. Child. Fetal Neonatal Ed. 1997;76:F31-F34

37. Persistent Hydronephrosis without Obstruction
10-15%
50% resolves by 12 months
Needs long time follow-up

38. Take Home Messages Antental hydronephrosis is not uncommon
With the high percentage of history of consanguinity, the incidence might be higher in Saudi Arabia
The Obstetrician should be vigilant in looking for it during the routine antenatal visits.

39. .....continue Take Home Messages
No evidence exists demonstrating the benefit of antenatal intervention in terms of renal function and only in a select number of cases will it benefit pulmonary function.
To our knowledge no scientific data exist that demonstrate the long-term benefit of early delivery of cases with antenatally detected, genitourinary abnormalities.

40. Thank You