Renal disease during pregnancy is relatively common in department of nephrology Bach Mai hospital. Effect of renal disease on course of pregnancy is unknown. A retrospective analysis of 64 pregnant women was carried out in department of nephrology. Pregnant women were analyzed with respect to degree of renal impairment for the effect of renal disease on course of pregnancy, complications during pregnancy and perinatal outcome. Outcome of 50 pregnancies was available during the study period. 23.4 percent patients with impared renal function. Obstetrical complications included a high frequency of preterm delivery before 38 weeks (80.2 percent). Overall fetal survival rate was 70 percent. The mean (SD) birth weight of babies born to mothers with before 38 weeks gestation was 1675g) and there were 2766g after 38 weeks' gestation. Mothers with renal insufficiency have high frequency of preterm delivery. In conclusion, pregnant women with renal insufficiency have increased rates of complications such as high frequency of preterm delivery, The birth weight of babies being delivered by renal insufficiency mothers was lower significantly compared with stable renal function mothers.