Nephrolithiasis during pregnancy

  • Nephrolithiasis specifically refers to the case whereby calculus (hard particles of minerals and acidic salts) is formed in the kidneys.  

  • Is nephrolithiasis common in pregnancy?
  • Around 10% of the population suffers from nephrolithiasis (kidney stones), and in the last two decades this number has increased. The top cause for non-obstetric hospital admission during pregnancy is nephrolithiasis / renal colic.
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  • What are the specific factors that favor the occurrence of nephrolithiasis in pregnancy?
  • During pregnancy, there are many conditions that "facilitate" the formation of stones such as the dilation of ureter (mainly the right one), increased urine calcium, uric acid, sodium and increased urine pH in pregnancy. These factors favor the formation of calcium phosphate stones, as opposed to the general population where most of stones are still calcium oxalate.
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  • Can kidney stones cause pregnancy complications?
  • Renal kidney (or more correctly the ureter) has been associated with some maternal and fetal complications such as premature labor and premature rupture of the membranes, but the evidence is contradictory.
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  • What are the symptoms of nephrolithiasis?
  • Pain in the lumbar spine is the predominant symptom (85% - 100% of the cases) and is usually accompanied by nausea, vomiting, microscopic or macroscopic hematuria and cystic irritation disorders.
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  • How is nephrolithiasis diagnosed during pregnancy?
  • Apart from the specific conditions that contribute to stone formation, there are also specific limitations on the diagnosis of nephrolithiasis. The radiography of the kidneys is not of interest in the diagnosis (as in the general population) due to Gamma irradiation. The first-line diagnostic test is kidney - utere ultrasound. Approximately 50-60% of the stones is detected with the use of the ultrasound. CT pyelography due to Gamma radiation cannot be used during a pregnancy. As an additional diagnostic imaging technique in finding this stone, transvaginal ultrasound can be used to help differentiate the normal ureteral dilation from obstruction of the urinary tract and can identify mainly lower ureteric stones located close to the bladder. 

  • What are the treatments for nephrolithiasis during pregnancy?

The treatment initially is similar as that of the general population. Hydration and analgesics but NO nonsteroidal anti-inflammatory drugs (which are considered contraindications to pregnancy) will be enough to eliminate the stone. This approach is acceptable when the stone is <1 cm and there is no infection. Its success rate reaches 70-80%. In case of failure of the conservative method, which occurs in about 30% of the patients, surgical intervention is required, either because the intense pain does not resolve with the medication or because there is evidence of persistent obstruction or infection of the urinary tract. Then the urologist should intervene by placing a pig tail stent in the ureter. It is a plastic tube inserted into the uterer to prevent or treat obstruction of the urine flow from the kidney and restore the flow of urine through it to thebladder. This will save time until the delivery, and then all the diagnostic and therapeutic processes will be allowed. Ureteroscopy is an advanced technique that allows the doctor to remove the stone endoscopically by looking inside the urinary tract. However, extracorporeal shock wave lithotripsy cannot be used since it is contraindicated during pregnancy.

  • Mesogeios Dialysis Centers Group Scientific Team
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  • Bibliography
  • 1. Stamatelou KK, Francis ME, Jones CA, Nyberg LM, Curhan GC. Time trends in reported prevalence of kidney stones in the United States: 1976–1994. Kidney Int. 2003;63:1817–1823.
  • 2. Odvina CV, Pak CYC. Medical evaluation of stone disease. In: Stoller ML, Meng MV, editors. Urinary Stone Disease: A The Practical Guide to Medical and Surgical Management (Current Clinical Urology). Totowa, NJ: Humana Press Inc; 2007;259–268.
  • 3. Asplin JR. Obesity and urolithiasis. Adv Chronic Kidney Dis. 2009;16:11–20.
  • 4. Scales CD Jr, Smith AC, Hanley JM, Saigal CS; Urologic Diseases in America Project. Prevalence of kidney stones in the United States. Eur Urol. 2012;62:160–165.
  • 5. Scales CD Jr, Curtis LH, Norris RD, et al. Changing gender prevalence of stone disease. J Urol. 2007;177:979–982.
  • 6. Dudley A, Riley J, Semins MJ. Nephrolithiasis and Pregnancy: Has the Incidence Been Rising? American Urological Association, Abstract #. 2013:68.
  • 7. Maikranz P, Coe FL, Parks JH, Lindheimer MD. Nephrolithiasis and gestation. Bailleres Clin Obstet Gynaecol. 1987;1:909–919.
  • 8. Maikranz P, Lindheimer MD, Coe F. Nephrolithiasis in pregnancy. Bailleres Clin Obstet Gynaecol. 1994;8:375–386.
  • 9. Rosenberg E, Sergienko R, Abu-Ghanem S, et al. Nephrolithiasis during pregnancy: characteristics, complications, and pregnancy outcome. World J Urol. 2011;29:743–747.
  • 10. Meria P, Hadjadj H, Jungers P, et al. Stone Formation and Pregnancy: Pathophysiological Insights Gained From Morphoconstitutional Stone Analysis. J Urol. 2010;183:1412–1418.
  • 11. Drago JR, Rohner TJ Jr, Chez RA. Management of urinary calculi in pregnancy. Urology. 1982;20:578–581.
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