Abstract: Objective To study the relationship between the mutation of mitochondrial DNA（mtDNA） T16189C and the risk of gestational diabetes mellitus（GDM）. Methods Totally,204 patients with GDM were enrolled as GDM group,and 220 healthy pregnant women were enrolled as control group. The general data of all the pregnant women,including age,gestational week,body mass index（BMI）,fasting blood glucose（FBG）,oral glucose tolerance test（OGTT） 1 h blood glucose,OGTT 2 h blood glucose,glycated hemoglobin A_1c（HbA_1c） and fasting insulin（FINS）,were collected. The homeostasis model assessment for insulin resistance（HOMA-IR） was calculated. The genotype of mtDNA 16189 mutation was determined by sequencing. Results The mutation rate of this site of GDM group was higher than that of control group（P<0.05）. The mtDNA T16189C mutation can increase the risk of GDM [odds ratio（OR）=1.36,95% confidence interval（CI） 1.020-1.823]. GDM patients were classified into carrying group and non-carrying group according to the mtDNA T16189C mutation. The levels of OGTT 1 h blood glucose,OGTT 2 h blood glucose,FINS and HOMA-IR in carrying group were higher than those in non-carrying group（P<0.05）. There was no statistical significance for FBG and HbA_1c between the 2 groups（P>0.05）. Conclusions The mtDNA T16189C mutation can increase the risk of GDM,and mtDNA T16189C mutation is risk to GDM.

Key words: Mitochondrial DNA, Variation site, Gestational diabetes mellitus