chpt 63 fetal uriogenital Flashcards
what are the three set of excretory organs that develop in the embryo
- pronephrous2. mesonephrous 3. metanephrous
permanent kidney
metanephros
The permanent kidney develops ?
early in the 5th week
When does urine formation begin?
early in the first timester, around the 11th and 12th week
urine is excreted into the _______ and forms major part of ____________.
amniotic cavity, amniotic fluid
T or F; The kidney does not need to filtrate in utero? Why
True; because the placenta elimates waste from fetal blood
T or F; The kidney lie far apart in the pelvis
false; kidney lie close together
The kidneys migrate into the abdomen and seperate from one another around ______ week of gestation.
9th
T or F; in some cases one kidney can stay in the pelvic cavity while the other migrates into the posterior flank of the abdomen
True
pelvic kidney may appear in females as?
pelvic masses
arterial supply to the kidney comes from?
arteries that arise from the aorta
At least ______% of adult kidneys have two or four renal arteries
25%
The female urinary bladder derives from?
hindgut
hindgut is know as?
urogenital sinus
the caudal end of the mesonephretic ducts opens into the?
cloaca; and parts are absorbed into the urinary bladder wall
distingushing sexual characteristics begin during the _____ week and external genital organs are fully developed by the _____ week
9th week; 12th week
fetal testis produce ? and cause?
they produce androgens; and cause masculinization of the external genitalia
what elongates to form the penis?
phallus
the ______ swelling grow toward the median plane and fuse to form the _______.
labioscrotal; scrotum
The testis remain near the deep inguinal rings until ____ weeks
28th
failure to complete the descend of the gonads is?
cryptorchidism
the gonads descend through the ____ and enter the scrotum before birth.
ingunal canal
uretha and vagina both open into the ____?
ureogenital sinus/ vestibule of the vagina
the uerogenital folds become the ?
labia minora
the labioscrotal folds become the ?
labia majora
the phallus becomes the ?
clitoris
the formation of the uterus is dependent on?
the fusion of two paramesonephreic ducts (mullerian ducts)
what happens if fusion of the paramesonephrenic ducts is incomplete? compete failure of this fusion will cause?
1.duplication of the uterus or vagina may occur 2. duplication of the entire femal tract or bicornuate uterus(duplicaton of uterus and one vagina)
what is uterus didelphys?
double uterus and double vagina
If only one paramesanephric duct develops this will cause?
unicornuate uterus (single uterine tube and horn)
At least 86% of fetal kidneys may be image at ____ weeks
12th
kidneys should be documented in all fetuses songraphically at ____weeks.
18
When kidney appear enlarged and echogenic ?
infantile polycystic diseast (with oligohydraminos), adult polycystic disease (normal amniotic fluid volume), Meckel-Greuber, trisomy 13
The kidneys are hyperechoic with regard to surrounding tissues at ____weeks.
18-20
describe the kidneys songraphically at 25 weeks.
relatively homogeneous renal cortex and parenchyma, hypoechoic pyramids and calyces, and anechoic renal pelvis
Where should the kidneys be visualized?
adjacent to the spine
If kidney is not well seen the fetal pelvis should be scanned to rule out?
ectopic kidney
Is it possible to have a unilateral kidney agensis?
yes; the contralateral kidney will be enlarged to compensate
on transverse image the renal pelvis is measured? and
anterior to posterior diameter when the fetal spine is toward the maternal anterior wall
What is the upper normal limit for transverse scan of the kidney?
_ 4mm up to 33 wks gestation and 7mm from 33 weeks of gestation until term_
The ureters usually measure____ in diameter and are filled with fluid.
less than 1 to 2 mm
T OR F; NORMAL URETER ARE ALWAYS SEEN
FALSE
DILATION OF THE POSTERIOR URETHRA IS HIGHLY SUSPICIOUS FOR ?
OBSTRUCTIVE PROCESS CALLED POSTERIOR URETHRAL VALVE SYNDROM (KEYHOLE BLADDER SIGN)
POSTERIOR URETHRAL VALVE SYNDROME OCCURS IN _______ AND IS MANIFESTED BY THE PRESENCE OF __________?
MALE FETUSES; A VALVE IN THE POSTERIOR URETHRA
WHAT IS A ROUND ECHO FREE AREA LOCATED CENTRALLY IN THE PELVIS?
BLADDER
HOW LONG DOES IT TAKE THE BLADDER TO FILL AND EMPTY?
30 MINUTES
EXTERNAL GENITALIA IS DIFFERENTIATED IN THE ______ TRIMESTER?
SECOND
In second trimester, identification of the female should only be documented when?
major and minor labia is seen
Abnormal congenital opening of the male urethra on the undersurface of the penis
Hypospadias
accumulation of serous fluid around the testicle, resulting from communication with the peroneal cavity and are generally benign
hydrocele
what is the critial marker in the assessment of renal function?
amniotic fluid
the fetal kidneys begin to excrete urine after the _____ week and do not become the major contributor of fetal urine until_____?
11th; 14-16 weeks
Name the two categories of Renal malformations?
1.congenital malformation 2. resulting from obstruction process
complete absence of the kidney
renal agenesis
letal disorder because of renal insuffiency and hypoplasia of the lungs
bilateral renal agensis
the presence of at leat one functioning kidney
unilateral renal agensis
what makes it difficult to image the kidneys
oligohydraminos
what determines if the kidneys are present or not?
presence or absence of the urinary bladder
unilateral renal agensis is estimated to occur in?
1 in 600-1000 births
bilateral renal agensis is referred to as?
Potters syndrome
what diseases are associated with potter’s syndrome?
diesease associated with renal failure, oligohydraminos, pulmonary hypoplasia, abnormal facies, malformed hands and feet
T or F; Potter’s syndrome can be uni or bilateral?
True
Potter’s Type 1
autosomal recessive infantile polycystic kidney disease
Potter’s type 2
Renal agensis; multicystic dyplastic kidney, renal dysplasia
Potter’s type 3
autosomal dominate polycystic kidney disease
Potter’s type 4
renal dysplasia; obstructive kidney disease
autosomal recessive disorder that affects the fetal kidneys and liver
infantile polycystic kidney disease
IPKD is characterized by?
development of small cyst on both kidneys and liver
most sever IKPD is associated with?
renal failure, oligohydraminos, and absent urinary bladder
What is a characteristic finding of Potter’s syndrome 1?
symmetric enlargement of both kidneys secondary to renal collecting tube dilation
What occurs in most severe cases of IPKD?
renal failure
Intrauterine diagnosis of IPKD should only be considered when the following characteristics are found:
- family history of IPKD
- bilateral enlarged kidneys
- highly echogenic kidney texture
- significant oligohydramnios
- inability to ID the fetal bladder
When may enlargement of kidneys from Potter’s syndrome 1 occur?
24th week, so serial studies are recomended
With Potters syndrome 1, why are kidneys so massively enlarged?
hundreds of dilated tubules
Multicystic Dysplastic Kidney Disease (MCKD) is characterized by:
What is the most common form of renal cystic disease in childhood and represents one of the most common abdominal masses in the neonate?
multicystic dysplastic kidney disease
T/F: Incidence of MCKD is found more often in females than males.
False, males
Although most cases of MCKD are unilateral, nearly ______ of cases are bilateral
1/4
Associated abnormalities of Potters syndrome 2 / MCKD may involve:
the contralateral kidney, heart, central nervous system, extremities, and GI syndromes
The prognosis for infants with MCKD varies based on
prenatal findings
When both kidneys are found to be multicystic, oligohydramnios and an absent bladder are expected;
a lethal condition exists for the neonate
If only one kidney is affected the other may enlarge as a result of:
compensatory hypertrophy
Describe the multicystic dysplastic kidney:
- composed of multiple smooth walled, non functioning, non communicating cysts of variable size and number
- kidney borders are difficult to define
- ureter and renal pelvis may be atretic and the renal artery is hypoplastic or absent
Adult dominant polycystic kidney disease (ADPKD) is associated with:
-cystic dilation of the nephrons and of the collecting tubule walls in both kidneys
What is the most common of the heredditary diseases?
Adult dominant polycystic disease
Prognosis of prenatal diagnosis of APKD depends on the progression of
cyst development leading to renal failure
The sonographic appearance of ADPKD is similar to what?
autosomal recessive polycystic renal diease (kidneys are symmetrically enlarged and echogenic)
T/F: ADPKD (potters syndrome 3) is nearly always bilateral
True
When does renal dysplasia occur secondary to renal obstruction?
in the 1st or early second trimester of pregnancy
Unilateral obstructive cystic disease can be caused by:
a uteropelvic or ureterovesical junction obstruction
bilateral obstructive dysplasia is caused by:
severe bladder outlet obstruction, usually urethral atresia or posterior urethral valves
Prognosis of Potter’s syndrome Type 4 (obstructive cystic disease) depends on
unillateral or bilateral involvement
Bilateral involvement of PS4/ obstructive cystic disease indicates
a poor outcome resulting from renal failure and lung hypoplasia
Early son. findings of PS4/ obstructive cystic disease:
hydronephrosis or hydroureter..but as kidney stops functioning, the cortex becomes completely dysplastic and replaced with the multiple cortical cysts
How do dsyplastic kidneys appear?
small and echogenic with cortical peripheral cysts
If obstructive cystic disease is bilateral, look for
- early bladder outlet obstruction (keyhole bladder)
- bilateral hydronephrosis
- thick-walled bladder
- sever oligohydramnios
When does renal ectopia occur?
when the kidney lies outside of its normal position in the renal fossa..usually in pelvis
What is crossed renal ectopia?
- when the ectopic kidney lies on the opposite side of the abdomen relative to its utereral insertion into the bladder
- kidneys are usually fused together and found on right side of abdomen
Is crossed renal ectopia found more in males or females?
males
With horseshoe kidneys, if the spine is down;
the connecting isthmus may be seen anterior to Aorta
Where may the urinary tract by obstructed?
- ureteropelvic junction
- ureterovesical junction
- level of urethra (megacystistis)
Amount and degree of urinary tract obstruction depends on
the gestational age at which the obstruction began
If urinarytract obstruction occurs early,
a multicystic kidney may develop
If the obstruction occurs in the late first trimester or second trimester:
cystic dysplasia may result
Late obstruction produces:
hydronephrosis
What is the most common fetal anomaly?
fetal hydronephrosis
Up to 22 weeks, hydronephrosis looks
the measurements of the renal pelvis are uniform
After 22 weeks, how does hydronephrosis look?
the obstructed kidneys produce increased renal pelvic diameters and true hydronephrosis
Describe son appearance of hydronephrosis
- dilated renal pelvis, which often communicates with the calyces, is centrallly located and distended with urine
- remaining renal tissue may be ID’d in all but the most severe cases of hydronephrosis
Renal pelvis measurements in 2nd trimester:
4-10 mm
Renal pelvis measurements in 3rd trimester:
7-10 mm
What is an abnormal renal pelvis measeurment?
exceeding 10-15 mm in the AP direction in the transverse plane
What is the most common reason for hydronephrosis in neonates?
ureteropelvic junction obstruction
HOw many obstruction disorders are found during early childhood?
1/2, so early prenatal detection may improve long-term renal function
What are the causes of ureteropelvic junction obstructions?
- abnormal bends or kinks in ureter
- adhesions
- abnormal valves in ureter
- abnormal outlet shape at the ureteropelvic junction
- absence of the long muscle that is imperitive to the normal excretion of urine from kidney
UPJ obstruction is usually a _______ defect
unilateral ; amniotic fluid remains normal because of the normal contralateral kidney
What is a urinoma?
a large cyst in contact with spine associated with ureteropelvic junction obstruction
Uterovesical junction obstruction commonly presents with
dilation of lower end of ureter (megaureter)
What may megaureter result from?
- primary ureteral defect (stenotic ureteral valves or fibrosis)
- secondary to obstruction at another level (causing reflux of urine)
With obstructed urinary tract, the affected kidney shows what?
- dilation of the renal pelvis
- tortuous dilated ureter
- duplication of the renal collecting system
When a dilated upper renal pole is observed with abnormal lower pole:
an obstructed duplicated collecting system may be indicated
What is a ureterocele?
a cystic dilation of the intravesical (bladder) segment of the distal ureter
What is an ectopic ureter?
one thaat does not insert near the posterolateral angle of the trigone area of the bladder
Where does an ectopic ureter insert for females?
- vagina
- vestibule
- uterus
Where does an ectopic ureter insert in males?
- seminal vesicle
- vas deferens
- ejaculatory ducts
What is bladder outlet obstruction produced by?
a membrane within the posterior urethra
What does posterior urethral valve obstruction result in?
- hydronephrosis
- hydroureters
- dilation of the bladder and post. urethra
What causes the keyhole sign?
posterior urethral valve obstruction which causes urine to be unable to pass through the urethra into AF..bladder wall is severly thickened with a dilated posterior urethra
Oligohydramnios results in what lung and chest problems?
lungs are hypoplastic, chest circumference is severelyl depressed.
Severe oligohydramnnios is a classic finding of
complete obstruction form
What abnormalities should be considered in the female fetus with sonographic findings consistent with obstructive urinary tract abnormalities?
- sacrum anomaly (caudal regression)
- megacystis-microcolon intestinal hypoperistalsis syndrome
Prune belly syndrome is AKA
urethral obstruction malformation complex
Prune belly syndrome/ urethral obstruction malformation complex consists of:
- cryptorchidism
- agenesis of abdominal wall muscle
- megaureters
- bladder outlet obstruction caused by urethral anomalies, such as atresia, stenotic valves, or diverticulum
Son findings of prune belly syndrome:
- oligohydramnios
- mild to severe bilateral hydronephrosis
- fetal ascites
- hypoplastic lungs
- abdomen is extremely distended compared with small thoracic cavity
- dilated ureters ad bladder appear as numerous cystic lesions within distended abd. cavity
- bladder may be obstructed and massively dilated or may rupture and not be seen except thru ascites
Describe true hermaphroditism
- rare condition in which both ovarian and testicular tissues are present
- internal and external genitalia are variable
- most fetuses have normal karyotype
What karyotype does a female fetus with pseudohermaphroditism have?
46XX
The most common cause of pseudohermaphroditism in females is
congenital virilizing adrenal hyperplasia that causes masculinization of the external genitalia (enlarged clitoris, abnormalities of urogenital sinus, and partial fusion of the labia majora)
The male fetus with pseudohermaphrodistism has what karyotype?
46XY and testes
What does male psuedohermaphroditism look like?
variable external and internal genitalia depending on developement of the penis and genital ducts
What is hydrometrocolpos?
- collection of fluid in the vagina and uterus, sometimes seen in conjunction with a doube uterus and septated vagina
- sometimes fluid is so large that it extends into the abd. cavity or may cause compression of the ureters and hydronephrosis of kidneys
Son. findings of hydrometrocolpos
- hypoechoic “cystlike” mass posterior to the bladder in the area of the uterus
- may be predominately cystic, may contain midlevel echoes, or fluid-debris levels
Echoes within hydrometrocolpos may result from
mucous secretions
What do ovarian cysts in fetuses result from?
maternal hormonal stimulation and is usually benign
Differential considerations for ovarian cysts in fetuses:
- mesenteric cyst
- urachal cyst
- enteric duplication
Sonographic findings of fetal ovarian cysts?
multiseptated and bilateral
What happens when an ovarian cyst twists on itself?
- torsion
- rupture
- or intestinal obstruction
