ERU-28&29 The Fetal GI and GU Systems Flashcards
When does the fetal gut develop?
End of the 5th week
What anomalies are often associated with esophageal atresia
duodenal atresia, VACTERL association, Down syndrome, IUGR, tris 18
What does “double bubble” sign indicate?
Duodenal atresia
Duodenal atresia is associated with what diagnosis?
Tris 21, esophageal atresia, VACTERL association
With what diagnoses is hepatomegaly associated?
Beckwith-Wiedemann, Rh incompatability, intrauterine infection
hirschprung disease
Absence of innervation in the bowel wall resulting in bowel obstruction
Dilated fetal rectum noted on US
Gastroschisis vs Omphalocele
G: Herniation of abd contents through a right-sided, periumbilical abd wall defect. Better prognosis. Less association with chromosomal abn.
O: An midline abd wall defect where there is herniation of the fetal bowel and other abdominal organs into the base of the umbilical cord. Cord inserts into midline of mass
By what week of gestation should physiologic herniation resolve?
12
What is the most common type of colonic atresia?
anorectal atresia
When should the fetal stomach be visible on US?
14 weeks
When do fetal kidneys form?
9 weeks formed
10 weeks functional
What is the urachus and where is it located?
A canal connecting the fetal bladder with the allantois (membrane that contributes to bladder development)
Located between the apex of the bladder and the umbilicus
When should the fetal bladder be visible on US?
By 15 weeks
VACTERL
Vrtebral anomalies Anal atresia Cardiac anomalies TracheoEsophageal fistula Renal anomalies Limb anomalies
What does “lying down” adrenal sign indicate?
Renal ageneisi
Meckel-Gruber syndroms
A fetal disorder that includes renal cystic disease, occipital encephalocele and polydactyly
Multicystic Dysplastic Renal Disease
Findings include multiple, smooth walled, noncommunicating cysts of varying sizes in the renal fossa
Usually unilateral. Fatal if bilateral
Caused by early obstruction of the ureter
Obstructive Cystic Dysplasia
Caused by early obstruction
Associated with peripheral renal cysts, ureterocele, thick walled bladder and hydronephrosis
What is a normal renal pelvic diameter?
<20w : 7mm (AP plane). Borderline 4-6mm
>20w: 10mm. Borderline 5-9mm
What does “keyhole sign” indicate on US?
Bladder outlet obstruction
Prune Belly Syndrome
Caused by megacystis and a massively dilated urinary bladder. Usually seen in males 2/2 urethral abnormality.
Absent abd muscles, undescended testis, and urinary tract abn
OEIS
Omphalocele, exstrophy of the bladder, imperforate anus, and spina bifida.
Most common cause of solid fetal renal mass
Mesoblastic nephroma
What is the most common malignant abd mass in neonates?
Neuroblastoma, usually located in the adrenal gland
