FETAL GUT ANOMALIES-DR NIRANJAN PATIL

1. USG FETAL GUT
PART-2
DR.PRAJAKTA MORE

2. ECTOPIC KIDNEY
• An ectopic kidney, also known as renal ectopia, is a congenital renal anomaly
characterized by the abnormal location of one or both of the kidneys.
• The estimated incidence of an ectopic kidney varies by location:
1. one normal and one pelvic kidney - 1 in 3,000
2. crossed renal ectopia - 1 in 7,000
3. ectopic thoracic kidney - 1 in 13,000
4. solitary pelvic kidney - 1 in 22,000

3. PELVIC
KIDNEY

4. PELVIC KIDNEY

5. THORACIC KIDNEY

7. PRUNE BELLY SYNDROME
• Prune-belly syndrome (PBS) refers to an abnormally
lax abdominal wall secondary to extensive stretching
during early development.
• It consists of three major findings-
1. gross pelvicalyceal and ureteric dilatation with renal
dysplasia
2. anterior abdominal wall underdevelopment
(resulting in the "prune belly" appearance)
3. bilateral undescended testes (Cryptorchidism) in
males.

8. On USG
Small kidneys with abnormal dilatation of calyces and ureters bilaterally. Large
urinary bladder with thin wall and wide neck can be observed. There can be a
patent urachus or urachal diverticulum.
• Differential diagnosis:-
1. Posterior urethral valves(keyhole sign and no e/o cryptochidism)
2. Megacystis microcolon intestinal hypoperistalsis syndrome (a/w
polyhydromnios and more females affected )

11. Megacystis Microcolon Intestinal
Hypoperistalsis Syndrome
• It is an autosomal recessive condition occurring more commonly in females.
• It presents with evidence of a functional small bowel obstruction, a microcolon
with intestinal malrotation, a markedly enlarged bladder, and bilateral
hydronephrosis.
• The bladder finding is not secondary to a physical obstruction, as the condition is
characterized by normal amniotic fluid volume and even polyhydramnios in late
pregnancy.
• There may be associated anomalies of other organ systems, including omphalocele,
cleft lip/palate, and cardiac defects, and the condition is associated with a poor
prognosis that becomes apparent in the newborn period.

13. ADRENAL GLANDS
• The fetal adrenal glands are easily demonstrated, especially using transvaginal
transducers, by the end of the first trimester. They appear as pyramidal hypoechoic
structures at the superior aspect of the hyperechoic kidney
• During the third trimester, the appearance of the fetal adrenal gland is very similar to that
of the neonatal adrenal glands
• In cases of renal agenesis, the adrenal gland is more prominent and may be elongated,
giving the so-called “lying down adrenal sign”.

14. 2ND TRIMESTER 3RD TRIMESTER
1ST TRIMESTER

15. ADRENAL MASSES
• Cystic or solid masses in the region of the adrenal gland may be secondary to benign
cystic enlargement, hemorrhage, Congenital Adrenal Hyperplasia, or adrenal tumors.

16. NEUROBLASTOMA
• Neuroblastoma may present with a cystic, solid, or more complex appearance
• Color Doppler imaging may demonstrate increasing vascularization of the hyperechogenic
aspects of the mass.

17. FETAL BLADDER ABNORMALITIES
• Fetal urine production begins at 8 to 10 weeks of gestation, and visualization of the
bladder in the pelvis is typically possible from 11 to 12 weeks’ gestational age.
• Persistent inability to identify the bladder beyond 15 weeks’ gestation is a pathologic
finding.
• The presence of normal amniotic fluid volume in the absence of a visible bladder
indicates either that the urine produced is unable to reach the bladder or that the
bladder is unable to hold the urine.

19. NON-VISUALISED
BLADDER
KIDNEYS
NO
ABSENT AMNIOTIC
FLUID
B/L RENAL
AGENESIS

20. BLADDER EXTROPHY
• The integrity of the fetal ventral wall depends on migration of mesenchymal cells between
the abdominal ectoderm and the cloaca. This process is initiated in the 4th week of
gestation, and its failure results in a lack of muscle and connective tissue in the
infraumbilical abdominal wall.
• It should be suspected when there is persistent nonvisualization of the bladder in the
setting of normal amniotic fluid volume and absence of other urinary tract abnormalities.
• Conditions that may obscure the diagnosis of bladder exstrophy include other ventral wall
defects, such as omphalocele, gastroschisis, and cloacal exstrophy.
• MRI has more recently been advocated as a useful adjunct in evaluation of suspected
cases.

21. USG Findings include-
• absent bladder in the pelvis
• a soft tissue mass (the exstrophied bladder)
adjacent to the lower abdominal wall
• low umbilical cord insertion with parallel course
of intra abdominal umbilical arteries.
• abnormal external genitalia (small phallus and
anteriorly deviated scrotum)
• separation of the iliac crests
• Normal AFI

25. CLOACAL EXSTROPHY
• A rare combination of anorectal and urogenital malformations.
• Cloacal exstrophy is in the spectrum of the OEIS complex (omphalocele, cloacal exstrophy,
imperforate anus, and spinal anomalies)
• OTHER FEATURES INCLUDE-
1. cystic anterior abdominal wall mass
2. presumed to represent a persistent cloacal membrane
3. abnormal external genitalia
4. renal anomalies (hydronephrosis, agenesis, and MCDK),
5. lower extremity defects
6. single umbilical artery.

26. The MRI findings allowing a confident diagnosis of cloacal exstrophy included a protruding
lower abdominal/pelvic contour and absence of meconium filling of the rectum and colon, a
manifestation of the hindgut anomaly.

29. GENITAL ABNORMALITIES

30. • The critical period for sexual development appears to be 8 to
12 weeks of gestation
• Ultrasound technology allow a confident diagnosis of fetal
gender at 13 weeks’ gestation.
• In the late first and early second trimesters, gender
determination is based primarily upon the sagittal sign. When
scanned in the sagittal plane, the normal penis points upward,
whereas the clitoris is oriented downward. Subsequently,
identification of fetal sex depends upon visualization of the
scrotum and penis in males and labia in females, which
present as either two or more parallel lines.
• Adjunctive findings that may be useful in uncertain cases
include presence or absence of testicular descent,
penile/scrotal size, origin and direction of the urinary stream,
and visualization of the uterus.

32. • Hypospadias
• Virilization syndromes
(clitoromegaly, fused labia)
• Incomplete masculinization of male
genitalia (micropenis), and
• Discordance between fetal
phenotype and karyotype

33. HYPOSPADIASIS
• It is a abnormal location of the urethral orifice, which may be along the
penile shaft, in the margin of the scrotum, or in the perineum.
• It reflects failure of development of the anterior urethra and has a reported
incidence of 1 : 250 to 1 : 5000 live births.

34. The prenatal sonographic features observed with hypospadias include -
• Loss of the pointed tip of the penis, which appears instead as a pointed cone;
• Abnormal ventral curvature of the penis (chordee),presumed secondary to a strand
of connective tissue acting as a bowstring between the meatus and glans;
• A small penile shaft with two parallel echogenic lines representing the remains of
the dorsal hood;
• The tulip sign, which results from severe curvature of the penis between the two
scrotal folds.

38. CASE
• Primi at 17-18 weeks of gestation
• On USG-
• B/L CTEV
• Enlarged adrenal glands
• Abnormal genitalia

41. CONGENITAL ADRENAL
HYPERPLASIA

42. • The most common cause of female virilization is
congenital adrenal hyperplasia (CAH)
• Most cases of CAH are from 21-hydroxylase
deficiency (CYP21 CAH)
• The affected female fetuses are at risk for genital
virilization.

43. FETAL OVARIAN CYSTS
• With improved ultrasound imaging, greater numbers of ovarian cysts are being diagnosed
prenatally.
• These cysts are secondary to maternal hormonal stimulation.
• They can be unilateral or bilateral, they may vary in size, and multiple cysts can occur on
the same side
• The most common cysts appear as anechoic smooth-walled, avascular cysts that may be
functional follicles
• Most fetal ovarian cysts resolve spontaneously, either in the ante- natal period or in the
early postpartum period.

45. HYDROCOLPOS/
HYDROMETROCOLPOS
• Malformations of the female lower genital tract resulting in obstruction of the lower half of
the vagina can result in fluid accumulation within the vagina (hydrocolpos) or in the vagina
and uterus (hydrometrocolpos).
• Some cases of hydrocolpos may resolve spontaneously, and, therefore, it is important to
exclude any associated anomalies to allow appropriate counseling and planning for
postnatal management.