Objective: To establish the prevalence of gestational diabetes in a universally screened population living in Messina, Sicily, as the first step in evaluating the cost: benefit ratio of screening for carbohydrate intolerance in pregnancy.
Study design: Between October 1989 and March 1995, 1,000 pregnant women underwent screening for gestational diabetes with a 50-g, one-hour glucose challenge test. All the risk factors were registered.
Results: Two hundred sixty subjects had a value of > or = 135 mg/dL and underwent a full three-hour oral glucose tolerance test. Of them, 46 (4.6%) met the Carpenter-Coustan diagnostic criteria for gestational diabetes.
Conclusion: The apparent incidence of gestational diabetes (1.2%) prior to screening was only 25% of the incidence determined with the protocol of universal screening (4.6%). If we assume that timely diagnosis and treatment of gestational diabetes provides an important opportunity to improve obstetric outcome and reduce perinatal morbidity, and since women with gestational diabetes are at increased risk of developing diabetes later, the knowledge that the true prevalence is almost four times that previously reported is a determinant of a future evaluation of the cost:benefit ratio of screening universally for gestational diabetes.