ABSTRACT
GDM is a common medical problem that results from an increased severity of insulin resistance as well as an impairment of compensatory increase in insulin secretion. GDM is associated with a variety of maternal and fetal complications. Controversy surrounds the ideal approach for detecting GDM, and the approaches recommended for screening and diagnosis are largely based on expert opinion. This study enrolled 51 pregnant women aged between 20 and 39 years old. All women were invited to do fasting and two hours postprandial blood glucose every two weeks, 2 hr. 75g OGTT every trimester. Plasma glucose measurements were performed with glucose oxidase method using semi-automated spectrophotometer [Biosystems 310]. Both normal and GDM cases have normal glucose tolerance in early weeks of pregnancy. However, after 24 weeks of gestation progressive increment of hyperglycemia was obviously observed in GDM cases. Suitable cutoffs in diagnosis of GDM in third trimester are 97 mg/dl for fasting; 174 mg/dl for 1 hour; and 141 mg/dl for 2 hour