Ortega-Gonzalez et al studied 50 healthy pregnant women, 50 GDM women and 50 pregnant women with type 2 diabetes TPO Ab> 251U/ml ( strongly positive) was found in 10% of healthy women, 10% of pregnant women with type 2 diabetes and 6% in women with GDM without statistically significant difference.25 Luisa R et al study evaluated Tg Ab and Anti TPO Ab in 408 GDM women and reported high titer of antibodies in 5% of study population.19 The difference between mentioned studies and our study could be due to regional differences, race and iodine consumption. Here, TPO is linked to type 2 diabetes mellitus.