To explore the feasibility of establishing a rat model of congenital abnormalities of the kidney and urinary tract (CAKUT) in offspring due to gestational diabetes mellitus (GDM). Methods Thirty naturally conceived SD rats were randomly divided into five groups by the concentration of streptozotocin (STZ) administered through a single intraperitoneal injection on day 1. 5 of gestation: 30 mg / kg STZ, 35 mg / kg STZ, 40 mg / kg STZ, solvent control (injected with the same dose of sodium citrate buffer), and blank control ( not injected with any liquid) group ( n = 6 in each group). Weight, blood glucose and abortion of pregnant rats were monitored during pregnancy. On the first day of delivery, the survival rates of offspring were calculated. Offspring were dissected and assessed for abnormalities of the urinary tract. HE staining of cross-sections of the offspring was performed, and renal and ureteral abnormalities were observed and recorded in multiple sections. Renal cortical thickness was measured in offspring. Results Ureteral dilatation and effusion (bilateral up to more than three times of unilateral) and renal dysplasia were observed in 30, 35 and 40 mg / kg STZ groups, and the total rates of ureteral effusion were >70%. HE staining revealed dilatation and effusion of the ureter, dysplasia of the ureteral wall, thinning of the renal parenchyma, and a reduction in the renal cortical thickness (more than 20% reduction compared with the blank control group). The blood glucose of all three groups reached the modeling standard, among which the mean blood glucose of the 30 mg / kg STZ group was lower than that of the 40 mg / kg STZ group (P<0. 05). Blood glucose in the 35 mg / kg STZ group was lower than that in the 40 mg / kg STZ group during early pregnancy (P<0. 05), and there was no difference during middle and late pregnancy (P>0. 05). Only pregnant rats in the 40 mg / kg STZ group aborted (33. 33% abortion rate), and survival rates in all three groups were lower than that in the blank control group (P<0. 05). Conclusions Establishment of a CAKUT model in offspring of GDM rats is feasible, and one intraperitoneal injection of 30 mg / kg STZ on day 1. 5 of gestation in SD rats safely and stably causes ureteral effusion (unilateral or bilateral) and renal dysplasia in offspring.