STUDIES OF POSTNATAL DIABETES-MELLITUS IN WOMEN WHO HAD GESTATIONAL DIABETES .1. ESTIMATION OF THE PREVALENCE OF UNRECOGNIZED PREPREGNANCY DIABETES-MELLITUS

This study investigated the prevalence of undiagnosed diabetes in wome n in the reproductive age group in a Victorian population by analysis of the results of glucose tolerance testing in 57,563 pregnancies. Ges tational diabetes (GD) was diagnosed in 4,243 pregnancies and in 2,957 (69.7%) of these, postnatal glucose tolerance testing was performed. Diabetes mellitus was diagnosed within 26 weeks of delivery in 59 wome n, 55 of whom were diagnosed by the postnatal glucose tolerance test ( GTT). There were 4 women with GD who developed diabetic ketosis during pregnancy (3) or within 12 weeks of delivery (1). By consideration of the results of the antenatal and postnatal GTTs, it was deduced that 53% (31 of 59) of the women with diabetes diagnosed after delivery may have had unrecognized prepregnancy diabetes. Consideration of the ent ire glucose-tolerance tested population led to the conclusion that app roximately 1 in 1,031 women in the reproductive age group in our commu nity have unrecognized prepregnancy diabetes mellitus.