Pregnancy and the kidneys

Abstract

Renal disease in pregnancy may cause a feeling of trepidation, even in the most experienced physician. However, before disease can be established, it is important to understand the substantial physiological changes that may occur during a normal pregnancy. Renal disease may take several forms and pregnancy may be the first medical review for women with a previously undiagnosed renal problem. Patients may have pre-existing renal disease, e.g. diabetic nephropathy. Additionally, women with renal transplants and renal diseases, e.g. lupus nephritis, require immunosuppression. Hypertensive disorders of pregnancy, including pre-eclampsia, are the commonest medical complications in pregnancy, and remain the most prevailing direct cause of maternal mortality in South Africa (SA). Both pre-existing hypertension and renal disease increase the risk of pre-eclampsia, which predisposes to preterm delivery, and maternal morbidity and mortality.
Pregnancy outcomes in renal disease are determined by baseline creatinine levels, hypertension and degree of proteinuria. The risk of progression of chronic kidney disease increases as renal function worsens. In SA, this is complicated by restricted access to dialysis in the state sector. To ensure the best outcome for mother and child, pre-pregnancy counselling and review of medication are essential. Renal patients and those with hypertension are at high risk of complications, and regular antenatal assessments by a multidisciplinary team are required to monitor blood pressure, proteinuria, diabetes control and fetal wellbeing.