For the study of the effects of maternal hyperglycemia upon the fetal distress. estimation of blood glucose saturation were made by Somogyi-Nelson`s method on maternal and umbilical venous blood before and immediately after delivery in 30 cases of normal full term pregnancy, which were divided into two groups, the first control group 10 cases whithout glucose injection, the other study group 20 cases with injection of 50% glucose 50cc. Injection of glucose was done intravenously 15 minutes-3hr before delivery and followed by checking the blood glucose saturation immediasely before and after delivery in the study group. The results were as follows, 1) The fetal cord blood sugar at birth was found to be lower than those of maternal blood sugar, before and after delivery in the both of control and study group. 2) And the absolute mean difference between maternal and fetal cord blood sugar shows 23. 85mg, 11.1mg in control group and 30.4mg, 16.7mg in the glucose-loaded group. 3) Fetal cord blood sugar of the glucose-loaded group shows 85mg higher than those of the control group. 4) It was also shown that free transfer of glucose through the placenta in case of normal pregnancy and can make a good effect upon the fetal distress.