A rationale for omitting two-hour postprandial glucose determinations in gestational diabetes.
OBJECTIVE
In making decisions regarding initiation of insulin therapy in gestational diabetes, most maternal-fetal obstetricians rely more on elevated fasting glucose values than on elevated 2-hour postprandial levels. We sought to determine whether the latter test is necessary.


METHODS
From the patients with gestational diabetes mellitus managed over a 17-month period at Grady Memorial Hospital, we retrospectively analyzed data to determine whether normal (< 105 mg/dl) fasting plasma glucose values predict elevated 2-hour postprandial values and whether the latter predict adverse outcome.


RESULTS
From 194 patients with gestational diabetes mellitus, 546 paired fasting and 2-hour postprandial glucose values were recorded. Fasting levels were normal in 467 (85%); in those, 2-hour levels were < 120 mg/dl in 83% and < 140 in fully 96%. In 131 women with all fasting plasma glucose values normal, the birth weights and the rates of cesarean delivery, shoulder dystocia, and macrosomia were similar, regardless of whether 2-hour postprandial glucose values were > or = 120. The actual cost of the 546 2-hour postprandial glucose tests was nearly $10,000.


CONCLUSIONS
For metabolic surveillance in gestational diabetes mellitus, the 2-hour postprandial glucose test seems unnecessary, provided fasting plasma glucose values remain normal.
Huddleston
J F
JF
Department of Gynecology and Obstetrics, Grady Memorial Hospital, Atlanta, GA.
Cramer
M K
MK
Vroon
D H
DH
D001724:Birth Weight; D001786:Blood Glucose / Q000032:analysis*; D002585:Cesarean Section / Q000706:statistics & numerical data; D016640:Diabetes, Gestational / Q000097:blood* / Q000175:diagnosis; D004435:Eating; D005215:Fasting / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D012189:Retrospective Studies
D001786:Blood Glucose