SPECIFIC CONTROVERSIES CONCERNING THE NATURAL-HISTORY OF RENAL-DISEASE IN PREGNANCY

Whether or not pregnancy adversely affects the natural course of underlying primary renal disease, and whether fetal outcome is influenced by the type of renal disease per se are controversial issues. We retrospectively analyzed the fetal and maternal outcome in 148 women with various, biopsy-proven histological types of primary chronic glomerulonephritis (GN), including IgA GN (52 patients), membranous GN ([MGN] 20 patients), membranoproliferative type I GN ([MPGN] 58 patients), focal and segmental glomerulosclerosis ([FSGS] 13 patients), and minimal change nephrotic syndrome ([MeNS] 22 patients), who were pregnant (with a total of 290 pregnancies) after the clinical onset of GN, and in 104 women with reflux nephropathy (with a total of 254 pregnancies). Fetal outcome was poor in the presence of uncontrolled hypertension, nephrotic range proteinuria, and/or impaired renal function at conception or early in gestation, whatever the type of renal disease. An accelerated, more rapid than expected, worsening of maternal renal function was observed in five GN patients of whom four (two IgA, two MPGN) had serum creatinine (Scr) levels greater than 160 μmol/L (1.8 mg/dL) early in gestation, and in five patients with reflux nephropathy whose Scr at conception ranged from 180 to 490 μmol/L (2.0 to 5.5 mg/dL). However, the overall actuarial time-curve free of chronic renal failure (Scr < 135 μmol/L) of the 148 patients who were pregnant after the clinical onset of GN did not differ from that of 172 female patients with the same types of GN who did not conceive, and a case-control study did not disclose a significant relative risk of developing chronic renal failure in relation to pregnancy. We conclude that pregnancy in patients with renal disease is essentially successful and uneventful when no risk factor is present at conception, whereas nephrotic range proteinuria, uncontrolled hypertension, and/or impaired renal function are independent, but additive factors of poor fetal prognosis. Markedly impaired renal function at conception (Scr > 160 to 180 μmol/L) (1.8 to 2.0 mg/dL), especially with concomitant uncontrolled hypertension, is associated with a high risk of accelerated worsening of maternal renal function, irrespective of the type of primary renal disease. © 1991, National Kidney Foundation, Inc.. All rights reserved.