The Fetal Genitourinary System (lesson 19b) Flashcards
By how many weeks gestation can the kidneys be identified and thoroughly evaluated?
22 weeks
Does fetal voiding decrease or increase bladder size?
Decrease
How often does the fetal bladder void?
Once per hour
What can help rule out bilateral renal dysfuction or agenesis, bilateral renal or ureteral obstruction?
Bladder filling, as it shows at least one kidney is doing its thing
By which weeks does fetal urine make up 90% of amniotic fluid?
20 wks
If oligiohydramnios is present after 16 weeks gestation, what is this suspicious for?
Malfunctioning GU system, because if baby’s not peeing, then something is up with the GU (geniturinary) system
What is the recurrence rate of renal agenesis in families?
50%
Unilateral agenesis is often correlated with which urinary tract anomalies of the contralateral kidney?
UPJ, VUR
In the case of unilateral agenesis, what happens to the single kidney?
Compensatory hypertrophy
Does unilateral agenesis result in a change in amniotic fluid or bladder filling?
No, it does not affect the amniotic fluid
What are some of the differential diagnoses for an empty renal fossa?
renal aplasia, renal dysplasia, multicystic dysplastic kidney, renal ectopia
(a.d.m.e.)
What anomalies have an increased incidence in association with renal ectopia?
Hydronephrosis and VUR, UTIs, and renal stones
What’s the most common location for an ectopic kidney?
Pelvis
What are the most common crossed renal ectopia?
Left to right crossover; upper pole of crossed ectopic kidney latches onto the lower pole of the normal kidney
What are some ultrasound findings that occur with crossed renal ectopia?
Calyceal dilation and hydronephrosis
What is a renal isthmus?
The connection between the two renal masses during a horseshoe kidney
What is the most common renal fusion anomaly?
Horseshoe kidney
What makes a MILD degree of hydronephrosis in SECOND trimester?
4 to < 7 mm
What makes a MODERATE degree of hydronephrosis in SECOND trimester?
7 to ≤ 10 mm
What makes a SEVERE degree of hydronephrosis in SECOND trimester?
> 10 mm
What makes a MILD degree of hydronephrosis in THIRD trimester?
7 to < 9 mm
What makes a MODERATE degree of hydronephrosis in THIRD trimester?
9 to ≤ 15 mm
What makes a SEVERE degree of hydronephrosis in THIRD trimester?
> 15 mm
What is one of the most common fetal uropathy anomalies detected on prenatal sonography?
Obstruction
What type of dilation is more common in fetuses with trisomy 21?
Pelvic dilation
What measurement are most kidneys with antenatal hydronephrosis normal at birth with? (answer in mm)
10 mm
When is a follow up ultrasound done when hydro is detected in the second trimester?
32 weeks
What is one of the key factors in determining postnatal pathology? (fluid related)
Oligio
What is APRPD?
Anterior posterior renal pelvic diameter; the renal pelvis measured
What is the most common cause of congenital obstructive hydronephrosis?
UPJ, ureteropelvic junction obstruction
What is the typical sonographic appearance of UPJ?
Severe unilateral hydronephorsis without ureteral dilation, and normal bladder
What is UVJ Obstruction?
Ureterovesical junction obstruction; hydro and dilatation of he ureter to the level of the bladder, without dilated bladder
What is the measurement for megaureter?
Greater than 7mm from 30wks onwards
What type of obstruction is most common in females?
Ureterocele
What is a ureterocele most commonly associated with?
Duplicated renal collecting systems
Ureteroceles found outside the bladder may simulate what?
Any pelvic cystic mass, ovarian cyst, anterior meningocele, or hydrocolpos
An enlarged bladder (megacystis) and bilateral hydronephrosis characterizes what type of obstruction?
Lower urinary tract obstruction (LUTO)
What are the two most common causes of LUTO?
PUV and urethral atresia
Urethral atresia is characterized by what?
Anhydramnioas and a largely distended bladder that fills the entire abdo and pelvis
What is the ‘keyhole sign’ associated with?
PUV (posterior urethral valves)
What is the least common type of PUV?
Type II: vertical of longitudinal folds between the verumontanum and prox prostatic urethra bladder neck
What is the most common type of PUV?
Type I: anterior fusing of the plicae colliculi, mucosal extending from the bottom of the verumontanum distally along the prostatic and membranous urethra
Prune belly syndrome is four times more common in what types of twins?
Monozygotic and dizygotic
What is the triad for Prune Belly Syndrome?
Distension of the anterior abdominal wall, obstruction of urinary tract, and bilateral cryptorchidism
What are the hereditary polycystic kidney diseases?
ARPKD (autosomal recessive) & ADPKD (autosomal dominant)
What are the nonhereditary polycystic kidney diseases?
MCDK (multicystic dysplastic kidneys)
What are the four types of ARPKD?
Perinatal, neonatal, infantile, and juvenile
PNIJ - J most popular
What is the leading cause of perinatal death?
Pulmonary hypoplasia related to oligiohydramnios
What is the most common inherited kidney disease?
ADPKD
Is MCDK typically unilateral or bilateral?
Unilateral
With MCDK, contralateral renal anomalies are a common finding - what is the most common renal anomaly found?
VUR
With MCKD, will the lungs develop normally?
Yes, as amniotic fluid level is not affected
In cases of PUV, urethral atresia, or UPJ obstruction, what type of kidney disease is most common?
Obstructive Cystic Dysplasia
Are simple renal cysts something to worry about, when on their own?
No
Renal tumours occur in which trimester?
Exclusively third trimester
Renal tumours are associated with what?
Polyhydramnios and subsequent premature labor
Adrenal glands are best visualized in which trimester?
Third trimester (but can be seen in the second trimester)
Is the prognosis of fetal neuroblastoma a good one if detected?
Yes, as these blastomas can spontaneously regress and do not require aggressive intervention
What does the bony pelvis consist of?
Iliac crests (echogenic) separated from the sacrum (echogenic) by the sacroiliac joint (hypoechoic)
What are the two major abnormalities in the pelvis?
Internal pelvic masses and sacrococcygeal teratomas
What are the most common urachal anomalies?
Urachal sinus and urachal cyst
If the bladder appears as a solid anterior abdominal wall mass, what can it be?
Bladder exstrophy
Bladder exstrophy can also look like what other two abnormalies?
Omphalocele or gastroschisis
What are some other diagnostic criteria for bladder exstrophy? (3)
Splayed iliac bones, epispadias, and small genitals
What are the sonographic findings of cloacal exstrophy?
Absent bladder, large midline infraumbilical anterior wall defect, omphalocele, and lumbosacral anomalies (myelomeningocele)
What is the OEIS complex?
Omphalocele, exstrophy of the bladder, imperforate anus, spinal anomalies (also known as cloacal exstrophy)
Which weeks are the genital tubercle in males and females indistinguishable?
Weeks 12-14
Downward angle of the tubercle indicates which sex?
Female
Upward angle of the tubercle indicates which sex?
Male
Are the normal ovaries, uterus, and vagina are typically seen within the fetus?
Yes, true.
What is hypospadias?
The abnormal development of the corpus spongiosum and cavernosa urthera due to incomplete fusion of urogenital folds.
What can be seen with hypospadias? (think balls)
Bifid scrotum
When does testicular descent occur abdominally?
10-15 wks gestation
When does testicular descent inguinally?
26-25 wks gestation
From what week can bilateral testicular descent be observed?
32 wks
Is it normal for a variable amount of fluid remaining from testicular descent into the scrotum to surround the testes?
Yes, normal
What can crypotorchidism be associated with?
Noonan syndrome, Klinefelter syndrome, multiple congenital anomalies, and masculinization of female genitalia
What might it mean if a hydrocele keeps enlarging?
A continued patency of the processus vaginalis
What could increasing scrotal volume indicate?
Inguinoscrotal hernia
What side do inguinoscrotal hernias most commonly occur on?
The right side
What are the most common intraabdominal tumours in female fetuses and neonates?
Fetal ovarian cysts
What may cause a fetal ovarian cyst to develop? (3)
Maternal hormonal stimulation, hypothyroidism, or diabetes
When are fetal ovarian cysts typically seen?
Third trimester
At what size do fetal ovarian cysts start to become worrisome for torison?
5cm
What is hydrocolpos/hydrometrocolpos?
Hydrocolpos - cystic dilatation of vagina
Hydrometrocolpos - cystic dilatation of vagina and uterus
How will you see hydrocolpos/hydrometrocolpos on ultrasound?
Midline anechoic or hypoechoic mass posterior to the bladder, can compress lower ureters
What are poor prognostic signs with hydrocolpos?
Associated renal dysplasia, oligohydramnios, fetal ascites, and resultant pulmonary hypoplasia
What does ‘disorders of sex development’ mean?
A congenital condition in which development of chromosomal, gonadal, or anatomical sex is atypical.
What is AIS?
(Androgen insensitivity syndrome)
Results in a normal female phenotype but amenorrhea presents at puberty and testes may be found