Efficacy of screening for gestational diabetes.

A cost analysis of glucose screening was studied prospectively in 434 patients. All patients underwent a 50-gm oral glucose load followed by a 1-hour plasma glucose screen test at 28 weeks (+/- 2 weeks). Patients with a screen test greater than or equal to 130 mg/dl plasma glucose were further tested with an oral glucose tolerance test. Also, previously described clinical risk factors for diabetes were documented on all patients. A 3.3% prevalence of gestational diabetes was found in 178 patients with risk factors, compared with 2.4% of 256 patients without risk factors, not a significant difference. Ten of the 12 gestational diabetics were at least 24 years old, so that screening only this subgroup would still retain a good sensitivity (83%) but at half the cost of universal screening. Screening on the basis of risk factors other than age is inefficient. Though testing only patients who are 24 years of age or older is more cost effective than universal screening, an individual decision must be made regarding its reduced sensitivity.