Effect of pregnancy on long-term function of renal allografts.

Pregnancy in renal allograft recipients is associated with hyperfiltration with the potential for glomerular damage and adverse effects on long-term graft prognosis. We have undertaken a case-controlled study of posttransplant follow-up for a mean of 12 years (range, 4 to 23) in 36 female renal allograft recipients, 18 who became pregnant and 18 controls (matched to underlying disease and renal function) who did not. Assessments included plasma creatinine (PCr), glomerular filtration rate (GFR) by infusion clearance of inulin (Cin), mean arterial pressure (MAP), and documentation of antihypertensive therapy. By the end of follow-up, PCr in the pregnancy group (112 +/- 73 mumol/L [1.26 +/- 0.83 mg/dL]) and controls (127 +/- 52 mumol/L [1.44 +/- 0.59 mg/dL]) had increased by 19% and 8%, respectively, and GFR in the pregnancy group (58 +/- 29 mL/min) and controls (56 +/- 32 mL/min) had decreased by 18% and 7%, respectively. Graft loss or chronic rejection occurred in two patients in each group and there was a death in the pregnancy group 9 years after the second of two successful pregnancies. MAP in the pregnancy group (96 +/- 12 mm Hg) had decreased by 1%, and in the controls (101 +/- 9 mm Hg) had increased by 5%. Two patients in the index group and three in the control group commenced antihypertensive therapy during follow-up. There was, therefore, no evidence of an adverse effect of pregnancy in renal allograft recipients on long-term renal function or development of hypertension.