title: Nephrolithiasis during pregnancy: characteristics, complications, and pregnancy outcome.
abstract: OBJECTIVE
  To evaluate obstetric complications and birth outcome in pregnant women with nephrolithiasis.
  
  
  METHODS
  A retrospective population-based study comparing all pregnancies of women with and without nephrolithiasis between 1989 and 2010 was conducted. Clinical characteristics were compared, and the obstetric risk factors and labor complication were analyzed. Multivariable logistic regression models were constructed in order to identify independent risk factors for nephrolithiasis.
  
  
  RESULTS
  During the study period, there were 219,656 deliveries, of which 195 women with nephrolithiasis were identified. Nephrolithiasis in pregnant women was significantly associated with recurrent abortions, mild preeclampsia, chronic hypertension, gestational diabetes mellitus, and cesarean deliveries. Nephrolithiasis was also significantly associated with urinary tract infections, pyelonephritis, hydronephrosis, and hydroureter. Nevertheless, no higher rates of premature rupture of membranes, preterm deliveries, or adverse perinatal outcomes (birth weight, Apgar scores or perinatal mortality) were noted in patients with nephrolithisais. Using a multiple logistic regression model, obesity (odds ratio 4.4, 95% confidence interval 2.1-9.0) and hypertensive disorders (odds ratio 2.8, 95% confidence interval 1.9-4.1) were independently associated with nephrolithiasis.
  
  
  CONCLUSIONS
  Maternal kidney stones are significantly associated with several pregnancy complications, including recurrent abortions, hypertensive disorders, gestational diabetes, and cesarean deliveries. Nevertheless, it is not associated with adverse perinatal outcomes. These findings raise the question regarding the proper management of small asymptomatic kidney stone in a pregnant woman.
authors.affiliation: Department of Urology, Faculty of Health Sciences, Soroka University Medical Center, Ben Gurion University of the Negev, P.O. Box 151, Be'er-Sheva, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Rosenberg
authors.forename: Ruslan
authors.initials: R
authors.lastname: Sergienko
authors.forename: Sara
authors.initials: S
authors.lastname: Abu-Ghanem
authors.forename: Arnon
authors.initials: A
authors.lastname: Wiznitzer
authors.forename: Igor
authors.initials: I
authors.lastname: Romanowsky
authors.forename: Endre Z
authors.initials: EZ
authors.lastname: Neulander
authors.forename: Eyal
authors.initials: E
authors.lastname: Sheiner
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology; D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D016640:Diabetes, Gestational / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D016015:Logistic Models; D008429:Maternal Welfare; D053040:Nephrolithiasis / Q000150:complications* / Q000000981:diagnostic imaging*; D011225:Pre-Eclampsia / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D014463:Ultrasonography