Difference in prevalence of gestational diabetes and perinatal outcome in an innercity multiethnic London population.

In order to establish the prevalence of gestational diabetes mellitus (GDM) among ethnic groups residing in the catchment area of one hospital in central London and to assess both the mode of delivery and the baby outcome, we studied retrospectively 703 women selected for screening for GDM during the years 1991 and 1992. While the prevalence of GDM was approximately 2% overall, within the ethnic groups a significant difference was found with Asians and Africans/Afrocaribbeans being four and two times more likely to have GDM, respectively, than Caucasians (P < 0.001). Both maternal obesity and the diagnosis of GDM influenced the time and the mode of delivery, but perinatal mortality and morbidity did not differ significantly between women with GDM and women with normal glucose tolerance. An association between the GTT glucose area and the gestational age and ethnicity adjusted birth weight was observed in women with normal glucose tolerance test, but was absent in the GDM pregnancies, providing indirect evidence that dietary treatment, with or without insulin treatment, altered the maternal milieu in the latter sufficiently to modify fetal growth.