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Urolithiasis in pregnancy. I: pathophysiology, fetal considerations and diagnosis

Urolithiasis in pregnancy represents a major diagnostic and therapeutic challenge to the GP, obstetrician, urologist, radiologist and anaesthetist. Urolithiasis presenting during pregnancy is a cause of major concern, considering the potential adverse effects of radiation exposure, any invasive surgical procedures and anaesthesia on the mother and fetus. The incidence of urolithiasis during pregnancy is 0.026–0.531% [2,3], complicates 1 : 200 to 1 : 2000 pregnancies [4] and may be a contributing factor in up to 40% of premature births [3]. The incidence of symptomatic stones has been calculated to be the same during pregnancy as in nonpregnant women of childbearing age [5]. Multiparous women seem to be affected more often than primiparae by a ratio of <3 : 1 [3,6,7]. However, the incidence in multiparous women is no greater when adjusted for age [8]. Folger [9] reported that pain resulting from urinary stones is the most common cause of abdominal pain requiring hospitalization during pregnancy. Leftand right-side calculi occur with equal frequency and ureteric stones seem to occur about twice as often as renal calculi. Interestingly, 80–90% of patients present in the second or third trimester of pregnancy, but rarely in the first trimester [10]. The management of urolithiasis during pregnancy is often challenging, requiring close co-operation between urologist, radiologist and obstetrician. Fortunately, with conservative management, 70–80% of symptomatic calculi pass spontaneously with no sequelae [10].