Marco teórico

Urolithiasis during pregnancy is a diagnostic and therapeutic challenge. In most cases, it becomes symptomatic in the second or third trimester (1,2).

8.1 Diagnostic imaging

Diagnostic options in pregnant women are limited due to the possible teratogenic, carcinogenic, and mutagenic risk of foetal radiation exposure. The risk for the child crucially depends on gestational age and amount of radiation delivered. X-ray imaging during the first trimester should be reserved for diagnostic and therapeutic situations in which alternative imaging methods have failed (1,3,4).

Ultrasound (when necessary using change in renal resistive index and transvaginal/transabdominal US with a full bladder) has become the primary radiological diagnostic tool when evaluating pregnant patients suspected of renal colic (1,5).

Statement LE

Normal physiological changes in pregnancy can mimic ureteral obstruction, therefore, US may not help to differentiate dilatation properly and has a limited role in acute obstruction.

3

X-ray imaging options in pregnancy are: limited excretory urography and NCCT (considering the higher dose of radiation exposure).

Magnetic resonance urography (MRU) can be used to define the level of urinary tract obstruction, and to visualize stones as a filling defect. MRU studies avoid ionising radiation and iodinated contrast medium. However, findings are non-specific and there is little experience using this imaging modality during pregnancy (6,7).

Recommendation LE GR

Ultrasound is the method of choice for practical and safe evaluation of pregnant women. 1a A* * Upgrade following panel consensus.

8.2

Management

Clinical management of a pregnant urolithiasis patient is complex and demands close collaboration between patient, obstetrician and urologist.

Approximately 70-80% of the symptomatic stones pass spontaneously. If spontaneous passage does not occur, or if complications develop (e.g., induction of premature labour), placement of a ureteral stent or a percutaneous nephrostomy tube is necessary (8-10). Unfortunately, these temporising therapies are often associated with poor tolerance, and they require multiple exchanges during pregnancy, due to the potential for rapid encrustation (11,12). Ureteroscopy has become a reasonable alternative in these situations (13-15). Although feasible, retrograde endoscopic and percutaneous stone removal procedures during pregnancy remain an individual decision and should be performed only in experienced centres (16). Pregnancy remains an absolute contraindication for SWL.

Statements LE

If intervention becomes necessary, placement of a ureteral stent or a percutaneous nephrostomy tube are readily available primary options.

3 Ureteroscopy is a reasonable alternative to avoid long-term stenting/drainage 1a Regular follow-up until final stone removal is necessary due to the higher encrustation tendency of stents during pregnancy.

Recommendation GR

Conservative management should be the first-line treatment for all non-complicated cases of urolithiasis in pregnancy (except those that have clinical indications for intervention).

A

8.3

References

1. Lewis DF, Robichaux AG 3rd, Jaekle RK, et al. Urolithiasis in pregnancy. Diagnosis, management and pregnancy outcome. J Reprod Med 2003 Jan;48(1):28-32.

http://www.ncbi.nlm.nih.gov/pubmed/12611091

2. Semins MJ, Matlaga BR. Management of stone disease in pregnancy. Curr Opin Urol 2010 Mar;20(2): 174-7.

http://www.ncbi.nlm.nih.gov/pubmed/19996751

3. Swartz MA, Lydon-Rochelle MT, Simon D, et al. Admission for nephrolithiasis in pregnancy and risk of adverse birth outcomes. Obstet Gynecol 2007 May;109(5):1099-104.

http://www.ncbi.nlm.nih.gov/pubmed/17470589

4. Patel SJ, Reede DL, Katz DS, et al. Imaging the pregnant patient for nonobstetric conditions: algorithms and radiation dose considerations. Radiographics 2007 Nov-Dec;27(6):1705-22. http://www.ncbi.nlm.nih.gov/pubmed/18025513

5. Asrat T, Roossin MC, Miller EI. Ultrasonographic detection of ureteral jets in normal pregnancy. Am J Obstet Gynecol 1998 Jun;178(6):1194-8.

http://www.ncbi.nlm.nih.gov/pubmed/9662301

6. Roy C, Saussine C, LeBras Y, et al. Assessment of painful ureterohydronephrosis during pregnancy by MR urography. Eur Radiol 1996;6(3):334-8.

http://www.ncbi.nlm.nih.gov/pubmed/8798002

7. Juan YS, Wu WJ, Chuang SM, et al. Management of symptomatic urolithiasis during pregnancy. Kaohsiung J Med Sci 2007 May;23(5):241-6.

http://www.ncbi.nlm.nih.gov/pubmed/17525006

8. Tsai YL, Seow KM, Yieh CH, et al. Comparative study of conservative and surgical management for symptomatic moderate and severe hydronephrosis in pregnancy: a prospective randomized study. Acta Obstet Gynecol Scand 2007;86(9):1047-50.

http://www.ncbi.nlm.nih.gov/pubmed/17712643

9. Mokhmalji H, Braun PM, Martinez Portillo FJ, et al. Percutaneous nephrostomy versus ureteral stents for diversion of hydronephrosis caused by stones: a prospective, randomized clinical trial. J Urol 2001 Apr;165(4):1088-92.

http://www.ncbi.nlm.nih.gov/pubmed/11257644

10. vanSonnenberg E, Casola G, Talner LB, et al. Symptomatic renal obstruction or urosepsis during pregnancy: treatment by sonographically guided percutaneous nephrostomy. AJR Am J Roentgenol 1992 Jan;158(1):91-4.

http://www.ncbi.nlm.nih.gov/pubmed/1727366

11. Zwergel T, Lindenmeir T, Wullich B. Management of acute hydronephrosis in pregnancy by Ureteral stenting. Eur Urol 1996;29(3):292-7.

http://www.ncbi.nlm.nih.gov/pubmed/8740034

12. Peer A, Strauss S, Witz E, et al. Use of percutaneous nephrostomy in hydronephrosis of pregnancy. Eur J Radiol 1992 Oct;15(3):220-3.

13. Semins MJ, Trock BJ, Matlaga BR. The safety of ureteroscopy during pregnancy: a systematic review and meta-analysis. J Urol 2009 Jan;181(1):139-43.

http://www.ncbi.nlm.nih.gov/pubmed/19012926

14. Rana AM, Aquil S, Khawaja AM. Semirigid ureteroscopy and pneumatic lithotripsy as definitive management of obstructive ureteral calculi during pregnancy. Urology 2009 May;73(5):964-7. http://www.ncbi.nlm.nih.gov/pubmed/19394491

15. Semins MJ, Trock BJ, Matlaga BR. The safety of ureteroscopy during pregnancy: a systematic review and meta-analysis. J Urol 2009 Jan;181(1);139-43.

http://www.ncbi.nlm.nih.gov/pubmed/19012926

16. Toth C, Toth G, Varga A, et al. Percutaneous nephrolithotomy in early pregnancy. Int Urol Nephrol 2005;37(1):1-3.

http://www.ncbi.nlm.nih.gov/pubmed/16132747

9. MANAGEMENT OF STONE PROBLEMS IN