Chronic kidney disease and pregnancy: maternal and fetal outcomes.

Chronic kidney disease complicates an increasing number of pregnancies, and at least 4% of childbearing-aged women are afflicted by this condition. Although diabetic nephropathy is the most common type of chronic kidney disease found in pregnant women, a variety of other primary and systemic kidney diseases also commonly occur. In the setting of mild maternal primary chronic kidney disease (serum creatinine <1.3 mg/dL) without poorly controlled hypertension, most pregnancies result in live births and maternal kidney function is unaffected. In cases of more moderate and severe maternal primary chronic kidney disease, the incidence of fetal prematurity, low birth weight, and death increase substantially, and the risk of accelerated irreversible decline in maternal kidney function, proteinuria, and hypertensive complications rise dramatically. In addition to kidney function, maternal hypertension and proteinuria portend negative outcomes and are important factors to consider when risk stratifying for fetal and maternal complications. In the setting of diabetic nephropathy and lupus nephropathy, other systemic disease features such as disease activity, the presence of antiphospholipid antibodies, and glycemic control play important roles in determining pregnancy outcomes. Concomitant with advances in obstetrical management and kidney disease treatments, it appears that the historically dismal maternal and fetal outcomes have greatly improved.