Disorders of glucose challenge test (GCT) in pregnant women referred to Khatam-o-allanbia

Gestational diabetes mellitus (GDM) is the most common metabolic disorderduring pregnancy which is associated with 3 to 4 folds of increase in the risk ofmaternal and fetal morbidity, if it is not diagnosed early (1). Gestationaldiabetes occurs from 1% to 14%, and 90% of pregnancy-related diabetes hasbeen related to gestational diabetes (2). Glucose challenge test (GCT) andglucose tolerance test (GTT) are recommended by American DiabetesAssociation (ADA) for screening and diagnosing of gestational diabetes (3).In this cross-sectional study, the subjects were the pregnant women during 24-28 weeks of gestation referred to Khatam-o-allanbia laboratory of Arak city in2009. First, we explained the aim of the project and then obtained the writtenconsent. After being fast for at least 8-12 hours, five ml of their venous bloodwas drown. For GCT, the blood samples were obtained one hour afterconsumption of 50g of glucose powder. The Individuals whose GCT was equalor higher than 130 mg/dl were introduced for GTT in the future days.After 8-12 hours of being fast, blood samples were taken to perform GTT.Then after eating 100 grams of glucose powder, their 1, 2 and 3 hour -venousblood samples were drown to perform glucose test, using glucose testing kit ofPars Azmun Company and Mindary BS-300 autoanalyser.The average age of referred pregnant women is 27.37±10.24 year. Of 417, 403(96.64%) have normal fasting plasma glucose (≤ 99 mg/dl) and 14 (3.36%)have abnormal fasting plasma glucose (≥ 100 mg/dl). When normal GCT isconsidered ≥140 mg/dl and ≥130 mg/dl, 357 (85.61%) and 308 (73.56%) havenormal GCT and 60 (14.39%) and 109 (26.14%) have abnormal GCT,respectively. The Average of fasting plasma glucose (FPG) and GCT are 83.86(73-243) and 118.32 (140-351) mg/dl, respectively. In 9 (64.29%) of womenwith abnormal FPG, the GCT test is also abnormal.By performing GTT for the women whose GCT was equal or higher than 130mg/dl, 24 (5.76%) were identified with gestational diabetes and introduced fortreatment. If 140 mg/dl was considered as a cutoff point of GCT, four women(0.94%) would falsely be non-diabetic. Based on this study, the prevalence ofGDM is 5.74% that is not so high, compared to the range of 4.8 to 7.4% of thecountry (4). A study conducted by Soheilykhah et al. on 1071 pregnant womenwith GCT of ≥ 130 mg /dl, 31.9% of the women had abnormal GCT. Afterdoing GTT, 110 patients (10.2%) have been diagnosed with gestationaldiabetes (2) that is higher than the prevalence of other studies in Iran.Due to results of this study and other studies, it seems that the GCT is not