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.

The distribution of renal disease varies significantly between the adult and pediatric population. Furthermore, given the advances in the understanding of renal diseases, the manner in which diseases are categorized and diagnosed has evolved over time. To study an up-to-date distribution of pediatric renal diseases, a retrospective review of all biopsy reports from patients between birth and 18 years of age, diagnosed at a central reference laboratory over a 5-year period (2016–2020), was performed. A total of 3,606 pediatric biopsies were reviewed, representing 4.63% of all samples (total: 77,941). Biopsies from native kidneys equaled 2,880, while those from allografts totaled 726. In native kidneys, glomerular diseases represented the overwhelming majority of diagnoses (76.6%), followed by tubulointerstitial diseases (15.65), normal biopsies (8.09%), limited samples (2.92%), non-specific chronic changes (2.74%), vascular diseases (1.8%), monoclonal immunoglobulin-related disease (0.17%) and, lastly, malignant infiltrating diseases (0.1%). On the other hand, allograft biopsies predominantly showed rejection (49.31%), either T-cell-mediated, antibody-mediated or a combination of both, followed by negative for rejection (46.42%) and limited samples (4.27%). Biopsies categorized as negative for rejection included acute tubular injury (17.77%), infarcts (0.41%), recurrent diseases (4.27%), de novo diseases (6.34%), polyomavirus nephropathy (2.75%) and normal histology (14.88%).