The term class H diabetes mellitus has recently been used to describe pregnant diabetic women with ischemic heart disease. In such patients, the risks of abortion may approach those of continuing the gestation. Because significant cardiac disease can occur with diabetes of even recent onset, a baseline electrocardiogram is thus recommended for all pregnant diabetic women. Review of the literature reveals 11 cases, 8 of which resulted in maternal death. The authors have successfully treated a class H diabetic woman who delivered a healthy infant at 36 weeks' gestation.