The aim of this study was assessment of total antioxidant status(TAS) in the second trimester pregnant women with gestational diabetes (GDM); impaired gestational diabetes mellitus (IGDM) and normal glucose tolerance (NGT). Increased free radical activity in gestational diabetes (GDM) can lead to a host of damaging and degenerative maternal and fetal complications. Hence antioxidant levels in the term ferric reducing ability of plasma (FRAP) of GDM could be given. 30 pregnant women in second trimester were evaluated in this study. They were divided in to three groups 10 pregnant having normal glucose tolerance (NGT group), 10 pregnant having impaired gestational diabetes mellitus (IGDM group ), and 10 pregnant having newly diagnosis gestational diabetes mellitus(GDM group) . Ferric reducing ability of plasma (FRAP) were estimated, in addition to BMI. The changes in FRAP in GDM was significantly different from controls. Hence, elevated glucose levels can induce oxidative stress in GDM. The average concentrations of total antioxidant in term FRAP were ( 414.7, 452.73, 858.4)μmole/L for NGT, IGDM, and GDM respectively. In this study there was a significant correlation( R2 =0.4685) between BMI (KG/M2) and serum glucose (mg/dl) after 2-hour oral glucose tolerance test (2-OGTT). The influence of plasma glucose level in the second trimester pregnant women with GDM or IGDM on the level of plasma antioxidant status (TAS) was also conducted in addition to the correlation between plasma glucose level and total antioxidant status in pregnant women with IGDM or GDM. The research was conducted at AL-Diwaniya Governorate, Al- Qadisiya university, College of medicine, department of clinical chemistry.