The basic cause of type 2 diabetes, whose prevalence is rapidly increasing worldwide, is genetic factors, with the addition of such acquired factors as lack of exercise, obesity caused by a high-fat diet, stress, and aging impairing insulin action,
leading to the onset of diabetes. In Japan, there is a clear trend towards delayed marriage and childbirth,
and in future the number of women with decreased carbohydrate tolerance who develop gestational diabetes mellitus (GDM) during pregnancy is expected to increase more and more. It is a fact that it is known that the incidence
of GDM increases by approximately 8 times for pregnant women aged 35 years and over compared with women aged 25 years or under. As shown in Table 1, pregnant women with carbohydrate intolerance are known to
develop various complications, and so blood glucose control is extremely important. Focusing particularly on GDM, this paper presents an outline of clinical issues as well as GDM diagnosis and management