Background: CD28 is an essential co-stimulatory receptor and is essential for successful T cell activation, proliferation, and survival. While it is ubiquitously expressed on naïve T cells, the level of CD28 expression on memory T cells is largely dependent on the stage of T cell differentiation in humans. Expanded CD4+CD28–T cells can produce large amounts of proinflammatory cytokines such as IFN-γ and TNF-α and also have cytotoxic potential, which may cause tissue damage and advance the pathogenesis of several inflammatory disorders. Here we review the characteristics of CD4 + CD28 - T cells in addition to recent developments that highlight the contribution of these cells to many pathological conditions. Objective: To estimate the percentage of T-cell, the pathogenesis of several inflammatory. Methods: 58 pregnant women with diabetes participated in the study, including 24 pregnant women with T1DM and 34 pregnant women with T2DM. C-peptide levels. Results: All pathological samples showed a decrease in CD4+ Tcell concentration compared to control. Samples taken from T1DM patients also showed a decrease in the presence of other diseases and bacterial infections compared to T2DM patients and the absence of bacterial infections. They also showed CD28 did not appear and there were no statistically significant differences. Conclusion: There was a positive correlation between CD4 + Tcell, CD28 immunoreactivity.