Renal colic in pregnancy: lithiasis or physiological hydronephrosis?

OBJECTIVES: To assess the reliability and accuracy of diagnostic investigations in differentiating urinary calculi from physiological hydronephrosis as the cause of renal colic. The appropriateness and efficacy of the treatments used were was also examined.
METHODS: A retrospective review of 300 consecutive patients presenting to 2 local hospitals was carried out. Descriptive and correlational data on clinical presentation, diagnostic imaging, and interventions undertaken were analyzed. A total of 262 patients were included in the final analysis.
RESULTS: Most clinical or laboratory features were unhelpful in predicting the presence of a stone. Left-sided colic was more likely to indicate presence of stone (64.9% vs 46.6%, P = .003). The accuracy of ultrasound findings in predicting presence of stone improved (from 56.2% to 71.9%) when features of obstruction, such as ureteric jet absence and an elevated resistive index (RI), were included in the assessment. Spontaneous resolution occurred in a smaller proportion of patients with stone (63% vs 85%, P <.001). The need for intervention was more prevalent in patients with stones (29.2% vs 5.9%, P <.001). Stent insertion was the most common intervention and was usually completed successfully (95.5%). Ureteroscopy was safe and resulted in stone retrieval 88% of the time.
CONCLUSIONS: Most clinical signs and symptoms are unhelpful in determining the cause of colic symptoms. Left-sided colic is more likely to represent the presence of a stone. An enhanced ultrasound examination is a reasonably accurate initial study. The standard endoscopic interventions are more likely to be used in colic cases because of actual calculi, and are safe and effective throughout pregnancy.