Lithogenic urinary changes occur during pregnancy. Such changes may increase stone proclivity in working and child rearing aged women thereafter. However, such an association has not been previously identified.
We analyzed nationally representative data from 2007-2012 National Health and Nutrition Examination Survey to assess the association between pregnancy and nephrolithiasis.
The weighted national prevalence of nephrolithiasis among women ≤50 was 6.4% (95% Confidence Interval (CI) 5.4%-7.6%). The prevalence of nephrolithiasis was significantly higher among women who had been pregnant compared with those who had never been pregnant (7.5% vs 3.2%, p=0.0004). On univariate regression, those who had been pregnant had over twice the odds of having had kidney stones (OR 2.44, 95% CI 1.50-3.98). An increased likelihood of nephrolithiasis among those with history of pregnancy persisted on multivariable logistic regression adjusting for age, ethnicity, obesity, history of diabetes, gout, hormone use, water intake and high sodium diet (OR 2.13, 95% CI 1.31-3.45). Finally, the adjusted prevalence of nephrolithiasis increased significantly with increasing number of pregnancies, from 5.2% in those with 0 reported pregnancies to 12.4% in those with 3 or more pregnancies (p=0.001).
Nephrolithiasis is strongly associated with prior pregnancies. Among women of reproductive age, the odds of stones are greater than doubled in those who had been pregnant compared with those never pregnant. Nephrolithiasis prevalence also increases with increasing number of pregnancies. Future investigation and identification of modifiable risk factors among pregnant patients may allow reduction in burden of stone disease in women.
The Journal of urology. 2017 Feb 23 [Epub ahead of print]
Lael Reinstatler, Sari Khaleel, Vernon M Pais
Dartmouth Hitchcock Medical Center Department of Surgery, Section of Urology, 1 Medical Center Drive Lebanon, NH 03784. Electronic address: ., Geisel School of Medicine at Dartmouth, 1 Rope Ferry Road Hanover, NH 03755. Electronic address: ., Dartmouth Hitchcock Medical Center Department of Surgery, Section of Urology, 1 Medical Center Drive Lebanon, NH 03784. Electronic address: .