GU Flashcards
Fetus begins to make urine
9w
Production of AF after 14w
2/3 of AF is produced by fetal urination, 1/3 from pulmonary fluid
If minimal hydro dx’d before 24 wks, __% resolution
90
Minimal fetal hydronephrosis - aneuploidy risk
Slight incr risk of T21, T13, Turner’s
MCC of significant neonatal hydronephrosis
UPJ obstruction
Grade 0 Hydronephrosis
Intact renal complex, nl renal parenchymal thickness
Grade 1 Hydronephrosis
Slight splitting of pelvis and calices, nl renal parenchymal thickness
Grade 2 Hydronephrosis
Evident splitting of pelvis and calices, nl renal parenchymal thickness
Grade 3 Hydronephrosis
Wide splitting of pelvis and calices, nl renal parenchymal thickness
Grade 4 Hydronephrosis
Further splitting of pelvis and calices, reduced renal parenchymal thickness
Ddx of minimal fetal hydronephrosis
Extrarenal pelvis, prominent renal veins crossing over renal pelvis, VUR
2nd trimester cutoff for hydronephrosis
4 mm
3rd trimester cutoff for hydronephrosis
7 mm
Primary causes of UPJ
Intraluminal valves, polyps, congenital mucosal folds, muscular hypertrophy, aberrant crossing vessels
Secondary causes of UPJ
VUR or more distal obstruction
VUR recurrence risk
high familial incidence, thought to be AD with reduced penetrance
UPJ obstruction before 10w, vs 2nd trimester
Before 8-10w => severe dysplastic changes -> multicystic dysplastic kidney
2nd trim -> pelvicaliceal dilation
Frequency & cause of polyhydramnios in UPJ obstruction
25-33% of cases, possibly due to impaired renal concentrating ability -> increased urine output
UPJ obstruction - assoc anomalies
horseshoe kidney, MDK, CDH, hydrocephalus, CCAM
UPJ obstruction - good prognosis
urine Na < 100 meq/L, Cl < 90 meq/L, osmolarity < 210 mosm/L, Ca < 2 mmol/L, PO4 < 2 mmol/L, B2-microglobulin < 4-6 mg/L
DDx of UPJ obstruction w/ bilateral hydronephrosis
Supravesical obstruction - Bilateral UPJ obstruction, bilateral ureterovesicular obstruction
Infravesical obstruction - PUV, urethral atresia, obstruction ureterocele
VUR (bilateral, usually high-grade)
Prune-belly syndrome
Megacystis-microcolon-hypoperistalsis syndrome
DDx of UPJ obstruction w/ unilateral hydronephrosis
UPJ obstruction Ureterovesical junction obstruction Multicystic dysplastic kidney Megaureter (nonobstructing, nonrefluxing; may be bilateral) Renal duplication (may be bilateral) Dilated loop of bowel
UPJ recurrence risk
Common, but usually sporadic
MCC of bladder outlet obstruction in males
Posterior urethral valves
MCC of bladder outlet obstruction in females
Urethral atresia
Def of enlarged bladder
> 3 cm length in 2nd trim, > 5 cm in 3rd trimester
Def of thickened bladder wall
> 2 mm
BOO - characteristic presentation
dilated bladder, bilateral hydroureteronephrosis
DDx of BOO
Supravesical obstruction - Bilateral UPJ obstruction, bilateral ureterovesicular obstruction
Infravesical obstruction - PUV, urethral atresia, obstruction ureterocele
VUR (bilateral, usually high-grade)
Prune-belly syndrome
Megacystis-microcolon-hypoperistalsis syndrome
BOO - aneuploidy risk
12% - T13, T18, T21
Ectopic ureterocele - aneuploidy risk
No known assoc with chromosomal abnl
Ectopic ureterocele - recurrence risk
Occurs sporadically, no increased risk of recurrence
What is ectopic ureterocele?
Ureterocele = cystic dilatation that occurs at the distal end of the ureter, at its jxn with the bladder. Ureteral orifice is located in an ectopic position, usually distal to the trigone. It is a rare cause of BOO, as the ureterocele can prolapse into the urethra.
