Urology>>>>>Renal Pathophysiology
Question 8#

Which of the following is TRUE in hydronephrosis of pregnancy?

A. The reported occurrence varies between 5% and 15%
B. The right kidney becomes hydronephrotic two to three times more commonly than the left
C. Approximately one half of patients have persistent hydronephrosis during the first postpartum week, but it resolves within 2 weeks of delivery in the majority
D. The use of MRI is advocated in the first trimester of pregnancy but gadolinium contrast should be avoided because it crosses the placental barrier
E. The majority of patients with symptomatic hydronephrosis of pregnancy can be managed with placement of ureteral stents or nephrostomy (especially if associated with pyonephrosis)

Correct Answer is B

Comment:

Answer B

The reported occurrence of hydronephrosis of pregnancy is between 43% and 100% (Faundes et al. 1998), the wide variation being due to different values used to report hydronephrosis. The right kidney becomes hydronephrotic two to three times more commonly than the left, probably because of interposition of sigmoid colon. Around one third of patients may have persistent hydronephrosis during the first postpartum week, but it resolves within 6 weeks in the majority. Despite the lack of solid evidence, MRI is not advocated in the first trimester of pregnancy (Leyendecker et al. 2004) and gadolinium contrast should be avoided in pregnant patients because it is known to cross the placental barrier. The presence of hydroureter upto the pelvic brim is readily apparent on T2 sequences and is characteristic of this condition. The majority of patients with symptomatic hydronephrosis of pregnancy can be managed with conservative measures. Rapid stent encrustation may be problematic, as urinary calcium excretion increases during pregnancy.