SELECTIVE SCREENING FOR GESTATIONAL DIABETES MELLITUS IN BUSHEHR, BASED ON A 50-GRAM CLUCOSE CHALLENGE TEST

The American Diabetes Association in 1997 switched its recommendations regarding the screening of pregnant women from universal to risk factor-based screening. The ADA specifically recommended that screening is not cost-beneficial in women under the age of 25, with a normal weight and negative family history of diabetes. 910 pregnant women attending the diabetes clinic at Bushehr University of Medical Sciences were screening for gestational diabetes using a 50-gram glucose challenge test. All the women were 24-28 weeks pregnant at the time of testing. Women with a post-load blood glucose of ≥140mg/dl were referred for a 3-hour oral glucose tolerance test. The presence of ADA risk factors was recorded, as was the absence of all three risk factors, and compared with the results of 50-gram GCT. We evaluated the predictive value of different combinations of risk factors relative to the results of screening. 66 women (6.9%) had a positive screening test, with 16 (1.75%) eventually diagnosed with GDM based on OGTT results. GCT was negative in 616 (95.3%) women, who had at least one of the three risk factors – age >25 years, BMI ≥27kg/m2, or a positive family history of diabetes – and in 231 (27.3%) women who had none of these risk factors [odds ratio = 70.3, 95%-CI = 2.23-22.21; p<0.0001]. Selective screening of pregnant women will detect most cases of gestational diabetes where resources to implement universal screening are limited. The most important factors in selecting screening candidates are age, body mass index, and family history of diabetes mellitus.