 To confirm these observations in the UK multi-ethnic population, the investigators plan to carry out an adequately powered case-control study to examine: a the influence of early pregnancy B12, folate and homocysteine levels as well as other clinical, biochemical and genetic markers on the risk of GDM and offsprings risk of future metabolic disorders by measuring detailed anthropometry of the babies along with their biochemical and genetic markers from the cord blood; and b the psychological impact of diagnosis of GDM by measuring the anxiety and distress by questionnaires. 