Objective:To investigate the expression of placental glucose transport protein (GLUT)1 and 4 in women with hyperglycemia in pregnancy.Methods:A total of 48 full-term singleton pregnant women who underwent elective cesarean section at Peking University First Hospital from January 2017 to December 2019 were included retrospectively, and were divided into pregestational diabetes mellitus (PGDM) group, gestational diabetes mellitus (GDM) group, and normal glucose tolerance (NGT) group (16 women in each). According to the blood glucose level after control during pregnancy, the PGDM and GDM groups were further divided into PGDM-, GDM-well controlled subgroups (both n=10), and PGDM-, GDM-uncontrolled subgroups (both n=6). The expression of GLUT1 and GLUT4 proteins, detected by Western blot, between different groups were compared and the correlation between GLUT1 and GLUT4 protein expression and the pre-pregnancy body mass index (BMI), pre-delivery weight,gestational weight gain (GWG), and neonatal birth weight were analyzed using two independent samples t-test, one-way analysis of variance, Kruskal-Wallis H-test, Chi-square test, and Pearson correlation analysis. Results:(1) The pre-pregnanct BMI and insulin treatment ratio in PGDM group were higher than those in GDM group and NGT group [27.0 kg/m 2 (22.1-29.9 kg/m 2) vs 22.9 kg/m 2 (20.5-25.7 kg/m 2) and 21.7 kg/m 2 (20.5-24.3 kg/m 2); 13/16 vs 1/16 and 0/16; all P<0.05]. In the PGDM group, fasting blood glucose at the second trimester and mean glycosylated hemoglobin during the second and the third trimester were higher than those in the GDM group [(6.1±1.2) vs (5.0±0.4) mmol/L; (5.9±0.5)% vs (5.2±0.3)%; both P<0.05]. (2) GLUT1 protein level was the highest in the PGDM group, followed by the GDM and NGT group (1.251±0.354 vs 1.004±0.368 vs 0.733±0.216, both P<0.05). And all the subgroups had higher protein level than NGT group [PGDM-good (1.270±0.417); PGDM-uncontrolled (1.218±0.245), GDM-well controlled (0.900±0.424); GDM-uncontrolled (1.177±0.158); LSD test,all P<0.05]. The variation of GLUT4 protein level was consistent with GLUT1. There was no significant difference in GLUT1 and GLUT4 expression between PGDM-uncontrolled and PGDM-well controlled subgroups, neither between GDM-uncontrolled and GDM-well controlled subgroups (all P>0.05). (3) GLUT1 and GLUT4 in the PGDM-well controlled subgroup, as well as GLUT1 in the GDM-uncontrolled subgroup, had a positive correlation with GWG ( r=0.635, 0.810, and 0.833, all P<0.05). Conclusions:The increased expression of placental GLUT1 and GLUT4 were associated with different types of gestational hyperglycemia and GWG. However, glucose control has little effect on placental GLUT expression.