Although in general the rate of caesarean section for GDM patients is high, there are some reports that this is due to the concern of physicians about shoulder dystocia occurring as the result of macrosomia, which has a high rate of frequency amongst GDM patients. However, much of the data is form the United States, and the average birth weight of infants born in the United States is higher than that in Japan. Thus it is thought to be impossible to use overseas data as the Japanese standard form the standpoint of infant birth weights.