The glucose challenge test for screening gestational diabetes in pregnant women with no risk factors.

AIM OF STUDY: To evaluate the 50 g glucose challenge test as a screening tool for gestational diabetes in pregnant women with no risk factors, to determine the prevalence of gestational diabetes in this population and to determine the perinatal outcomes of pregnancy according to the glucose challenge test.
METHODOLOGY: A descriptive prospective study. A total of 146 patients with no risk factors who booked a particular obstetrician and delivered between May 1996 and April 1997 were recruited. Pregnancy outcomes were assessed by the gestation and mode of delivery, neonatal outcomes included birth weights, apgar scores and other neonatal complications.
RESULTS: The detected incidence of gestational diabetes was 8.2%. With the threshold plasma glucose level at 7.1 mmol/l, 53 women or 36% needed to undergo the 75 g oral glucose tolerance test and 12 women were found to have gestational diabetes. The diagnostic yield was 22.6%. With 7.8 mmol/l as the threshold value, 28 women or 20% needed the oral glucose tolerance test and eight women with gestational diabetes were detected. The diagnostic yield was 28.6%. Perinatal outcome for these diabetic women who were well-controlled during pregnancy was similar to the rest of the women with normal glucose challenge test.
CONCLUSIONS: The 50 g glucose challenge test is a useful screening test for diabetes in Singaporean women with no risk factors. A threshold value at 7.8 mmol/l with a smaller number of women requiring the 75 g oral glucose challenge test may be more acceptable.