Renal calculi in pregnancy.

The recent published literature dealing with urinary tract calculi during pregnancy has been summarized. Our own experience with 17 patients, (0.08% of the deliveries) in a recent 12-year interval has been described. Emphasis must be placed on the safety and limitations of renal ultrasonography. Excretory urography should be performed in patients with urinary infection not responding after 48 hours of antibiotic therapy, with declining renal function, with massive hydronephrosis on renal echography, or with pain and dehydration from vomiting. The timing of postinjection films is critical; a 3-hour film and, if needed, a 6-hour film are recommended. Criteria for intervention (nonoperative or operative) include calculous pyelonephritis, persistent massive hydronephrosis with impairment of renal function, and protracted pain or sepsis.