Urinary calculi in pregnancy.

Despite earlier studies, there remain unanswered questions regarding urinary calculi in pregnancy. The authors studied 11 cases in 11,292 deliveries over 5 years. Eight previous studies were also studied and data were compiled from 96 cases in 138,296 patients. The incidence of urinary calculi in pregnancy is approximately 1 per 1500, with variance in geographic distribution. Symptoms may occur during any trimester but more often during the second and third trimesters. Incidence among multigravidas is twice that of primigravidas. Incidence on right and left sides is consistent. Because spontaneous passage occurs in more than 50% of cases, conservative therapy is the initial treatment of choice. However, if surgical therapy is indicated, maternal and fetal complications are rare.