Review of basic anatomic and physiologic changes in renal function during pregnancy and implications of these changes. This chapter highlights the impact of renal disease on pregnancy, fetal outcomes, and anesthetic management. The etiology and severity of chronic renal disease, end stage renal disease, and those who have had a renal allograft all have a crucial impact on pregnancy. These are all critically important to the obstetric anesthesiologist.

Many entities affect specifically the tubulointerstitium, most often sparing the glomeruli and vessels, but exact subclassification is difficult because the histologic findings may have overlapping features. Frequently biopsies are performed shortly after symptoms manifest (in the acute phase). There is controversy in the terminology of chronic lesions; for example the term chronic pyelonephritis, particularly in the pediatric population, has fallen out of favor, replaced by other terms such as reflux nephropathy. However, careful examination and clinicopathologic correlation helps to pinpoint the cause and guide appropriate patient management. In this chapter, the focus is on the histopathology of acquired and hereditary tubulointerstitial diseases in native kidneys.