Ureteral obstruction in pregnancy – The “Stone Mountain” for the Urologist

The management of ureteral obstruction in pregnancy remains controversial. Clinically oriented literature review on diagnostic and therapeutic decisions concerning renal colic in pregnancy has been published in this issue of the Central European Journal of Urology [1]. We all still face several challenges of differentiating renal colic in pregnancy caused by the uretheral stone or by physiological hydronephrosis. Unfortunately, clinical signs and symptoms or laboratory tests are all of poor clinical value and cannot be used to figure out the reason for hydronephrosis. Also, pregnancy trimester is not associated with the specific pathogenesis. Physiologic hydronephrosis is more common and severe on the right side because of anatomical reasons (dextrorotation of the uterus, protection of the left ureter by the gas-filled sigmoid colon), while left-sided flank pain is significantly more characteristic for the lithiasis [2]. Ultrasound is widely accepted as a primary imaging modality for the pregnant patient with renal colic [3], although its sensitivity in detecting ureteral stones is not always satisfactory. In many individuals, hydronephrosis is easy to be detected, unlike its cause. It remains unclear whether inconclusive ultrasound should be followed by other imaging studies. It is rather not justified in uncomplicated stone patients with good pain control and no infection, as the majority of the stones will be passed spontaneously. Moreover, pregnant patients with renal colic caused by physiological hydronephrosis can be effectively managed conservatively (pain control, rest, body positioning contralateral to the pain or in the knee-elbow position) with no need for intervention. The obstetricians tend to overdiagnose hydronephrosis and expect treatment with the DJ stent in majority of cases. Certainly DJ stents are not without complications and can result in infections, stent intolerance and excessive encrustation. Furthermore, pregnancy related physiological changes in the urinary tract can Ureteral obstruction in pregnancy – The “Stone Mountain” for the Urologist