EFFECT OF PREGNANCY ON RENAL-FUNCTION IN PATIENTS WITH MODERATE-TO-SEVERE DIABETIC RENAL-INSUFFICIENCY

OBJECTIVE - Previous studies of patients with diabetic nephropathy and mild renal impairment have suggested no deterioration in renal functi on as a result of pregnancy. The objective of this study was to determ ine whether pregnancy may permanently worsen renal function in women w ith diabetic nephropathy and moderate-to-severe renal insufficiency. R ESEARCH DESIGN AND METHODS - Eleven patients were identified with diab etic nephropathy and moderate-to-severe renal dysfunction (creatinine [Cr] greater than or equal to 124 mu mol/l [1.4 mg/dl]) at pregnancy o nset by retrospective chart review. Alterations in glomerular filtrati on rate were estimated by using linear regression of the reciprocal of Cr over time. An equal number of nonpregnant premenopausal type I dia betic women with similar degrees of renal dysfunction served as a comp arison group for nonpregnant rate of decline of renal function and pot ential contributing factors. RESULTS - Mean serum Cr rose from 159 mu mol/l (1.8 mg/dl) prepregnancy to 221 mu mol/l (2.5 mg/dl) in the thir d trimester. Renal function was stable in 27%, showed transient worsen ing in pregnancy in 27%, and demonstrated a permanent decline in 45%, Proteinuria increased in pregnancy in 79%. Exacerbation of hypertensio n or preeclampsia occurred in 73%. Seven patients progressed to dialys is 6-57 months postpartum, with 71% (five of seven) of these cases att ributed to acceleration of disease during the pregnancy. Student's t t ests and repeated-measures analysis of variance support a pregnancy-in duced acceleration in the rate of decline of renal function. CONCLUSIO NS - In this series, patients with diabetic nephropathy and moderate-t o-severe renal insufficiency were found to have a >40% chance of accel erated progression of their disease as a result of pregnancy.