[Urinary lithiasis and pregnancy]

The incidence of renal stones in pregnant women is 1 in 1500. The diagnosis may be made more difficult by the particular anatomo-physiological conditions of pregnancy. Ultrasonography is not always sufficient to localise the stone and can be completed by intravenous urography, which is not contraindicated in pregnant women. In more than one half of cases, the stones are eliminated spontaneously during conservative treatment. The urologist may need to intervene in the case of complicated stones: internal or external urinary diversion is generally sufficient to palliate the problem until term. As extracorporeal lithotripsy is contraindicated in pregnant women, some authors recommend ureteroscopy or percutaneous nephrolithotomy when radical treatment is required. Surgical treatment is very rarely indicated.