Aim of the work is to Study the amount of expression of CD34 on cord blood stem cells in babies of normal healthy pregnant females and compare their expression in unhealthy conditions (we choose diabetes mellitus as it is the commonest immunological disorder in pregnancyStem cells are characterized by their ability of self renewal and differentiation into different kinds of cells. The sources of stem cells are the bone marrow, the peripheral blood and the cord blood. All haematopoietic stem cells express CD34 on their surface.Recently, the cord blood has become an alternative source for stem cell transplantation instead of the bone marrow. Although the count of the stem cells in cord blood is enough, there is an increasing interest for its ex-vivo expantion by using different cytokines).