1. SON 2122 Obstetrical Sonography Part II
Chapter 16
The fetal Genitourinary tract
HHHoldorf

2. Outline Bladder Outlet Obstruction Posterior Urethral Valves
Normal Fetal Genitourinary System
Normal Fetal kidneys
Normal fetal bladder
Normal fetal adrenal glands
Genitalia
Renal Anomalies
Renal Agenesis
Polycystic Kidney Disease
Multicystic Dysplastic Kidney Disease
Solid Renal Masses
Neuroblastoma (Wilm’s Tumor)
Ureterovescial Pathology
UPJ Obstruction
Bladder Outlet Obstruction
Posterior Urethral Valves
Urethral Atresia
Cloacal Malformation
Prune Belly Syndrome
Female genital Tract
Ovarian cysts
Hydrometrocolopos

3. The normal GU system

4. Normal Anatomy  
Kidneys
Originate in the pelvis and migrate superiorly during gestation.
Can be seen as early as weeks
Renal pyramids are echo-poor
Renal sinus fat is more echogenic and can be seen in the hilum of each kidney.
Occasionally the renal pelvis may contain small amounts of fluid

5. Age-related renal pelvis measurements (AP)
Weeks mm
Weeks mm
Weeks 30-term 10mm

8. AP Renal Pelvis measurements
Less than or equal to 5mm is normal
5-10mm is probably normal. Should have a follow-up
Greater than or equal to 10mm: 85% have anatomic anomaly

9. Normal fetal kidneys-Transverse

10. Normal fetal kidney-sagittal

11. Can been seen at about 20 weeks Indicator or active renal function
Bladder
Can been seen at about 20 weeks
Indicator or active renal function
Empties and fills normally in minute cycles
If it’s not seen, don’t panic. Re-scan in 20/30 minutes. Then if you don’t see it, panic.

12. Fetal bladder with umbilical arteries

13. Normal fetal bladder

14. Adrenal Glands Large in the fetus. 90% is cortex
Seen as oval masses of echo-poor tissue lying superior to the kidneys on the Sagittal scan
Transversely, they appear long, thin and echogenic in the medulla and are surrounded by thicker sonolucent rims of cortex
They should be smaller than the normal kidney.

15. transverse normal adrenal gland

16. Sagittal normal adrenal gland

17. Genitalia
The determination of the gender of a fetus may assist in the differential diagnosis of GU anomalies and or chromosomal syndromes

18. Male genitalia

19. Female genitalia

20. RENAL ANOMALIES Renal agenesis
The congenital absence of one or both kidneys
Unilateral-very common and causes no symptoms
Bilateral (Potter’s syndrome)
Bilateral renal agenesis (BRA)
Pulmonary hypoplasia
Facial anomalies
Patients present as small for dates

21. BRA Associated with other stuff
Cardiovascular disease
Gastrointestinal disease
Skeletal and GU anomalies
Sonographic findings of BRA
Severe Oligohydramnios seen between weeks is not a good finding
Absent kidneys with “lying down” adrenal glands within the renal fossa (don’t mistake them for kidneys)
Bladder not extended

22. Bilateral renal agenesis

25. Bilateral renal agenesis

26. Unilateral renal agenesis

27. Unilateral renal agenesis

28. Polycystic Kidney Disease
Inherited disorder characterized by many bilateral cysts.
Cysts cause enlargement of the total renal size while reducing the functioning renal tissue.
Autosomal – recessive type (ARPKD) is diagnosed in utero.

29. ADPKD vs. ARPKD: What is the Difference?
Autosomal dominant (ADPKD) is one of the most common life-threatening genetic diseases.
ADPKD affects approximately 1 in 500. It does not skip a generation. There is usually a family history of ADPKD.
Parents with ADPKD have a 50 percent change of passing the disease on to each of their children.
Autosomal recessive (ARPKD) is a relatively rare genetic disorder, occurring in approximately 1 in 20,000 individuals.
It affects boys and girls equally and often causes significant mortality in the first month of life.

30. FOUR TYPES OF PKD
Perinatal-renal failure occurs in utero
Neonatal occurs within first month after birth; death within 1 year
Infantile- occurs by 3-6 months of age, with 20% renal involvement. Hepatosplenomegaly. It progresses to renal failure
Juvenile – appears at 1-5 years of age. Less renal involvement, but same result as infantile group.

31. Sonographic findings
Large kidneys-hyper echoic
Increased kidney to AC ratio
Bladder is usually small
Loss of cortico – medullary differentiation
Kidneys may appear normal in early pregnancy

32. Polycystic kidney disease 31st week of pregnancy; parasagittal scan at the level of the fetal kidneys show their hyperechoic appearance. Oligohydramnios was also present.

33. Polycystic kidney disease

34. Multicystic Dysplastic Kidney
Obstruction of the kidney during its development leads to formation of cysts which replace renal parenchyma.
MCDK is non-functioning
Cysts can be large, up to 6 cm
Cysts may be unilateral.
Cannot be detected EARLY in gestation…cysts are too small

35. Sonographic findings
If Bilateral
-multiple, randomly located variable sized cysts
-cannot see fetal bladder when renal insufficiency is present
-Oligohydramnios possible

36. If Unilateral
Multiple cysts in one kidney
Normal contra-lateral kidney
Bladder seen if “good” kidney is sufficiently operating

37. mcdc

38. Mcdk-bilateral

39. MCDK

40. MCDK

41. Solid Renal Masses Several types are possible, though rare
Mesoblasitc nephroma
Adrenal neuroblastoma
Sonographic findings
Presence of a solid mass in the renal fossa

42. Neonatal Adrenal mass-Neuroblastoma

43. Nephroblastoma A.K.A. Wilms tumor
Neruoblastoma: A cancer that is commonly found in the adrenal glands.
Nephroblastoma: Also called Wilm’s tumor, is a mass of cancer cells that grow in the kidney tissue.

44. Fetal Adrenal Neuroblastoma

45. Fetal nephroblastoma: Wilms’ tumor

46. Obstructive Uropathy
May vary in location
Bilateral obstructions may lead to renal dysplasia, renal failure, and death

47. Uretropelvic Junction Obstruction
UPJ obstruction is the most common cause of neonatal Hydronephrosis
There is an obstruction of urine flow from the renal pelvis to the ureter.
Causes: fibrous adhesions, kinks, ureteral valves.
Amniotic fluid volume is usually normal.

49. UPJ OBSTRUCTION in utero

50. Sonographic findings of a UPJ Demonstration of a dilated renal pelvis
Thinning of the renal cortex in chronic states

51. UPJ obstruction

52. Bladder Outlet Obstructions
Most BOBs occur in male fetuses.
Posterior Urethral valves are most common cause.
In females, cloacal malformations or urethral atresia are usually the cause.

53. PUV
Congenital folds of the urethra act as valves and obstruct urinary outflow.
PUVs can cause severe damage to the kidneys, ureters and bladder.

54. Sonographic findings
Marked bilateral Hydronephrosis and dilated, tortuous ureters
Bladder wall thickening
“keyhole” appearance of bladder-referring to dilated bladder and prostatic urethra
Moderate to profound Oligohydramnios
Male genitalia identified

55. PUV – Keyhole sign

57. Bilateral hydronephrosis from PUV

58. Urethral Atresia Can occur in both sexes
Complete obstruction due to absence of the urethra
Not compatible with life
No amniotic fluid after 16 weeks and pulmonary hypoplasia is certain

60. Cloacal Malformation Rare Convergence of the GI and GU tracts
Single opening in the perineum, which empties in both systems
Severe obstruction with Oligohydramnios.
Poor prognosis

61. Defined as confluence of rectum, vagina and urethra into a single common chamber that opens into a single orifice where the normal urethral opening is located

62. Cloacal malformation: 32 weeks -evaluation of a fetal cystic mass lesion in abdomen. Three cystic masses in lower abdomen with ascites were observed.  Amniotic fluid was normal. The bladder was not identified. Cloacal malformation was suspected. Post natal examination confirmed the diagnosis.

64. Persistent cloaca

65. Complex/Persistent Cloaca
Only in females
High incidence in Chinese girls
Seems to be part of the VACTERL syndrome
V Vertebral
A anorectal
C Cardiac
T Trachea-esophageal
R Renal
L Limb

66. Prune Belly Syndrome
Massive early dilation of the urinary bladder causes pressure atrophy of the abdominal wall
Most common cause is PUVs.
Decompression of Hydronephrosis post-natally causes retraction and wrinkling of the anterior abdominal wall skin,
Giving the appearance of a prune.
Associated with pulmonary hypoplasia and severe Oligohydramnios

67. Sonographic findings
Abnormal compression of abdominal wall by fetal small parts
Movement of fetal abdominal wall when maternal abdomen is tapped firmly.
Oligohydramnios
Bilateral Hydronephrosis and massively distended urinary bladder

68. Prune belly syndrome

69. Prune belly syndrome

70. Fetal Genital Tact Males
Undescended testes-normally descend into the scrotum between 26 and 34 weeks gestation
Hydroceles-small hydroceles are common. Large ones warrant postnatal follow-up
Abnormal formation of the penis
Females
Hydrometrocolopos
Ovarian cysts

71. Hydrometrocolopos
A collection of watery fluid in the uterus and vagina
Caused by vaginal atresia

72. Hydrometrocolopos

73. Ovarian cyst-in utero