This study was conducted to examine the association of perfluoroalkyl substance (PFAS) exposure with gestational diabetes mellitus (GDM) risk and postpartum fasting blood glucose.We used a 1∶2 matched case-control study with 84 GDM subjects and 168 healthy pregnant women from Beijing,China.The matal blood was collected at 1-2 days before delivery,and eight linear isomers and fourteen branched isomers were determined in matemal serum.Logistic regression analyses were performed to evaluate the associations after adjusting for potential confounders.The median of the sum of levels of total PFASs was 4.24 ng/mL with a interquartile range (IQR) of 2.82-6.54 ng/mL.Although matemal PFAS exposure was not associated with risk of GDM,significant positive associations were observed between evaluated exposure to specific PFAS congeners and increasing blood glucose.The odds ratio (ORs) of the highest category of postpartum fasting blood glucose for perfluoro-1-metylheptylsulfonat (1m-PFOS),perfluoro-3/4-metylheptylsulfonat (3m+4m-PFOS),perfluoro-5-metylheptylsulfonat (5m-PFOS),and perfluorohexane sulfonate (PFHxS) were 2.03 (95％ CI:1.09-3.77),1.93 (95％ CI:1.04-3.58),2.48 (95％ CI:1.33-4.65),and 2.26 (95％ CI:1.21-4.21),respectively,suggesting negative effects of matal exposure to spedfic PFAS compounds on glucose metabolism.