Abstract: AIM: To explore the value of velocity vector imaging(VVI) technology in detecting fetal left ventricular functions in pregnancy with gestational diabetes mellitus(GDM).METHODS: Digital dynamic four-chamber views of 54 normal fetuses and 54 fetuses with GDM were collected and analyzed offline using VVI.The regional tissue velocity,strain and strain rate of the six segments of the left lateral wall and the interventricular septum were measured in systole and diastole.RESULTS: Vs and Vd of left fetal ventricles in pregnancy with GDM increased with gestational age.Vs after 32 weeks and Vd after 28 weeks,and S,SRs and SRd after 24 weeks in left ventricles of fetuses with GDM were obviously lower than those of normal pregnancy(P<0.05).CONCLUSIONS: Fetal left ventricular functions are affected in pregnancy with GDM.VVI is a useful method to detect fetal left ventricular function in pregnancy with GDM.