Abstract:
517 pregnant women attended to antenatal clinic who underwent the screening with glucose
challenge test was studied. Women who exceeded the threshold for gestational diabetes
were subjected to oral glucose tolerance test. Oral glucose tolerance test was also done in
patients whose glucose challenge test was normal but later showed clinical features of
gestational diabetes or had known risk factors of gestational diabetes mellitus. The
sensitivity and positive predictive values in the index population were 75 percent and 25
percent respectively. In the group having a family history of diabetes the figures were 81
percent and 33 percent respectively. Among the women older than 30 years the figures were
82 percent and 30 percent. In the group having both risk factors the sensitivity and positive
predictive values were 92 percent and 42 percent respectively. Thus the sensitivity and
positive predictive values of the glucose challenge test are significantly increased in the
presence of known risk factors of gestational diabetes mellitus. As the sensitivity and
positive predictive values were low use of glucose challenge test for universal screening is
not cost effective. Significant increase in both of above figures in the presence of risk
factors favours selective screening of pregnant women for gestational diabetes mellitus.
