Answer for BIR CoW 11 June 2023
Physiological hydroureteronephrosis of pregnancy
Findings
Prominent bilateral pelvicalyceal system with bilaterally dilated ureters(right more than left) with smooth tapering noted at distal ureteric level.
Discussion
It is estimated that up to 90% of women have some degree of asymptomatic dilatation of the renal calyces, the renal pelvis and the upper two-thirds of the ureters during pregnancy . It is thought to be most pronounced in primigravid females. Collecting system dilatation is commonly observed with increasing frequency as pregnancy advances, as a result of combined hormone-induced ureteral relaxation and extrinsic compression by the gravid uterus at the level of the lumboiliac junction. A gradual increase in dilatation is usually seen throughout pregnancy in both kidneys, with the rate of increase greater on the right side than on the left. The crossing of the ureter by the ovarian vein at the pelvic brim on the right while running parallel on the left, dextrorotation of the uterus, and the relative protection of the left ureter provided by the sigmoid colon are the possible factors for right sided predominance. Ultrasound readily demonstrates hydronephrosis with perinephric fluid, absent ureteral jet and elevated (>0.7) intrarenal Doppler resistive index suggesting acute obstruction. Using heavily T2-weighted pulse sequences, MRU shows the static or slowly flowing urine as hyperintense because of its long relaxation time, against a very low signal background. Ureteral tapering above or below the uterus, an abrupt calibre change or distended pelvic ureter suggest an obstructive cause. There may be an association between gestational hydronephrosis and increased frequency of ascending urinary tract infection. In most cases, it disappears within a few weeks after birth. The vast majority of asymptomatic cases are treated conservatively especially since most cases of physiological calyectasis do not impair renal function.
References:
1. Fainaru O, Almog B, Gamzu R et-al. The management of symptomatic hydronephrosis in pregnancy. BJOG. 2002;109 (12): 1385-7. BJOG
2. Puskar D, Balagović I, Filipović A et-al. Symptomatic physiologic hydronephrosis in pregnancy: incidence, complications and treatment. Eur. Urol. 2001;39 (3): 260-3.
3. Ferguson T, Bechtel W. Hydronephrosis of pregnancy. Am Fam Physician. 1991;43 (6): 2135-7.
Findings
Prominent bilateral pelvicalyceal system with bilaterally dilated ureters(right more than left) with smooth tapering noted at distal ureteric level.
Discussion
It is estimated that up to 90% of women have some degree of asymptomatic dilatation of the renal calyces, the renal pelvis and the upper two-thirds of the ureters during pregnancy . It is thought to be most pronounced in primigravid females. Collecting system dilatation is commonly observed with increasing frequency as pregnancy advances, as a result of combined hormone-induced ureteral relaxation and extrinsic compression by the gravid uterus at the level of the lumboiliac junction. A gradual increase in dilatation is usually seen throughout pregnancy in both kidneys, with the rate of increase greater on the right side than on the left. The crossing of the ureter by the ovarian vein at the pelvic brim on the right while running parallel on the left, dextrorotation of the uterus, and the relative protection of the left ureter provided by the sigmoid colon are the possible factors for right sided predominance. Ultrasound readily demonstrates hydronephrosis with perinephric fluid, absent ureteral jet and elevated (>0.7) intrarenal Doppler resistive index suggesting acute obstruction. Using heavily T2-weighted pulse sequences, MRU shows the static or slowly flowing urine as hyperintense because of its long relaxation time, against a very low signal background. Ureteral tapering above or below the uterus, an abrupt calibre change or distended pelvic ureter suggest an obstructive cause. There may be an association between gestational hydronephrosis and increased frequency of ascending urinary tract infection. In most cases, it disappears within a few weeks after birth. The vast majority of asymptomatic cases are treated conservatively especially since most cases of physiological calyectasis do not impair renal function.
References:
1. Fainaru O, Almog B, Gamzu R et-al. The management of symptomatic hydronephrosis in pregnancy. BJOG. 2002;109 (12): 1385-7. BJOG
2. Puskar D, Balagović I, Filipović A et-al. Symptomatic physiologic hydronephrosis in pregnancy: incidence, complications and treatment. Eur. Urol. 2001;39 (3): 260-3.
3. Ferguson T, Bechtel W. Hydronephrosis of pregnancy. Am Fam Physician. 1991;43 (6): 2135-7.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!