Pregnancy in women with impaired renal function

The outcome and consequences of pregnancy in women with impaired renal function are still debated. To assess the benefit of recent advances in coordinated obstetrical and nephrologic management, we analyzed fetal and maternal outcome of 43 pregnancies in 30 women with various types of primary renal disease and moderate to severe renal failure at conception defined by serum creatinine concentration (Scr) ranging from 0.11 to 0.49 mmol/l. All pregnancies took place during the 20-year period from 1975 through 1994 and were prospectively followed jointly by our Nephrology Unit and Obstetric and Neonatology Units of University Hospitals. Of the 43 pregnancies (45 fetuses), 13 ended in fetal death (including 5 first-trimester abortions and 8 fetal deaths beyond the 20th gestational week). There were 32 live births, a success rate of 82% not considering first-trimester abortions. Successful pregnancies were significantly more frequent in the last decade than in the preceding one (91 vs 65%, p = 0.05). Overall live birth rate was higher in pregnancies started with Scr < 0.20 mmol/l than in those with Scr > 0.20 mmol/l (80% vs 53%, p = 0.02). The upper preconception Scr value associated with a successful fetal outcome was 0.27 mmol/l. Hypertension was the major factor of fetal prognosis, as the relative risk of fetal loss was 10.6 times higher when hypertension was present at conception or early in pregnancy than when blood pressure was spontaneously normal or well-controlled by therapy. An accelerated course toward end-stage renal failure was observed in 7 patients (23%), all of whom had severe hypertension and heavy proteinuria at conception. We conclude that fetal outcome in patients with impaired renal function has been improved in recent years, due to advances in obstetrics and neonatology, improved blood pressure control and close co-operation between nephrologists and obstetricians, but that a risk of fetal loss and of accelerated deterioration of maternal renal disease still persists when Ccr at conception is lower than 25-30 ml/ min/1.73 m2.