Predictive value of current imaging modalities for the detection of urolithiasis during pregnancy: a multicenter, longitudinal study.

PURPOSE: We determined the optimal imaging study by which to diagnose and treat pregnant patients with suspected urolithiasis. MATERIALS AND METHODS: A retrospective, multicenter study was performed to determine the comparative accuracy of imaging modalities used before the surgical management of suspected urolithiasis in pregnant patients. Patients with a clinical suspicion of urolithiasis were evaluated with directed imaging including renal ultrasound alone, renal ultrasound and low dose computerized tomography, or renal ultrasound and magnetic resonance urography. When indicated, patients underwent therapeutic ureteroscopy. The rate of negative ureteroscopy was determined and the positive predictive values of the imaging modalities were calculated. RESULTS: A total of 51 pregnant patients underwent ureteroscopy. The mean age of the cohort was 27 years. Mean gestational age was 24.4 weeks. Of the women 24 (47%) underwent renal ultrasound and low dose computerized tomography, 22 (43%) underwent ultrasound alone, and 5 (10%) underwent renal ultrasound and magnetic resonance urography. Negative ureteroscopy occurred in 7 of the 51 patients (14%). The rate of negative ureteroscopy among patients who underwent renal ultrasound alone, renal ultrasound and low dose computerized tomography, and renal ultrasound and magnetic resonance urography was 23%, 4.2% and 20%, respectively. The positive predictive value of computerized tomography, magnetic resonance and ultrasound was 95.8%, 80% and 77%, respectively. CONCLUSIONS: The rate of negative ureteroscopy was 14% among pregnant women undergoing intervention in our series. Of the group treated surgically after imaging with ultrasound alone, 23% had no ureteral stone, resulting in the lowest positive predictive value of the modalities used. Alternative imaging techniques, particularly low dose computerized tomography, offer improved diagnostic information that can optimize management and obviate unnecessary intervention.

Obstetric complications of ureteroscopy during pregnancy.

PURPOSE: During pregnancy a ureteral stone and its management may pose risks for the mother and fetus. Definitive ureteroscopic management of an obstructing stone during pregnancy has been increasingly used without a reported increased incidence of urological complications. However, the rate of obstetric complications of ureteroscopy during pregnancy remains undefined. MATERIALS AND METHODS: Charts of pregnant women who had undergone ureteroscopy at 5 tertiary centers were reviewed. Patient and procedure characteristics were collected. Records were evaluated for the occurrence of obstetric complications in the postoperative period. RESULTS: A total of 46 procedures were performed in 45 patients at 5 institutions. There were 2 obstetric complications (4.3%), including 1 preterm labor managed conservatively and 1 preterm labor resulting in preterm delivery. There was no fetal loss. No statistically significant characteristics were identified differentiating those patients having obstetric complications. CONCLUSIONS: Ureteroscopy performed during pregnancy has been previously reported to be urologically safe and effective for addressing ureteral stones. In our multi-institutional series a 4% rate of obstetric complications was observed. Based on this risk a multidisciplinary approach is prudent for the pregnant patient undergoing ureteroscopy.