First prenatal visit glucose screening.

In order to determine the benefit of glucose screening at different stages of pregnancy, a prospective study of 999 patients was performed. All the patients underwent a nonfasting glucose screen at their first prenatal visit. This screen consisted of an oral 50 gm glucose load followed by a 1 hour serum glucose determination. If the glucose result was 130 mg/dl or higher, a 3-hour oral glucose tolerance test was performed at that time. There were 228, 354, 122, and 295 patients with gestational ages less than 14 weeks, 14 to 23 weeks, 24 to 28 weeks, and more than 28 weeks, respectively. The group less than 24 years of age had a significantly lower mean screening glucose value (106.1 +/- 35.9 mg/dl) than the group whose age was 24 years or older (117.4 +/- 35.9 mg/dl). There were significantly fewer patients with elevated screening glucose values when the patients were less than 24 years of age. Nevertheless, in the final analysis, 13% of the gestational diabetics diagnosed were in the age group younger than 24 years. Although the majority of the diagnosed gestational diabetic had elevated screening glucose values after 23 weeks of gestation, 33% had positive screening tests before 24 weeks. Earlier glucose screening, regardless of maternal age or gestational age, can lead to an earlier diagnosis of gestational diabetes. Cost of universal screening, regardless of maternal age, is only slightly more expensive than a screening protocol with a minimum age limit.