Historical perspective of pregnancy in chronic kidney disease.

Preeclampsia was first recognized as a cause of proteinuria unique to pregnancy in 1843 and the risk of pregnancy in women with preexisting renal disease was noted in the 1930s. Since then, we have recognized that the majority of women with kidney disease who become pregnant have surviving infants. The exception is women on dialysis whose pregnancies result in only 50% to 75% of infant survival. All women with renal disease are at increased risk for hypertension during pregnancy, but the risk of more rapid than expected progression of renal disease generally occurs in women with serum creatinines greater than 1.4 mg/dL, with an even higher risk in women with serum creatinines greater than 2 mg/dL. Dialysis patients conceive infrequently and have a high frequency of fetal loss and neonatal death. Fertility is restored by renal transplant and guidelines are being developed regarding the ideal timing of pregnancy, the kidney function required for a safe pregnancy, and the use of immunosuppressive drugs in pregnancy.