Glucose challenge test does not predict gestational diabetes mellitus.
OBJECTIVE
It is widely acknowledged that identification and treatment of gestational diabetes mellitus (GDM) results in better maternal and neonatal outcomes. However, the utility of the glucose challenge test (GCT) remains controversial regarding the diagnostic approach and decision making.


METHODS
We performed a retrospective analysis on the database of our Laboratory Information System to retrieve results of GCT and oral glucose tolerance test (OGTT), which were performed on consecutive female outpatients referred by the gynecologists over the last 3 years.


RESULTS
Cumulative results for GCT and OGTT were retrieved for 724 female outpatients and screening test was abnormal in 114 of them. This group was classified in terms of normal glucose tolerance (NGT), one abnormal value for the 100-g-3h OGTT (OAV) and GDM. GDM was diagnosed only in 34 subjects (4.7%). No statistically significant differences were observed in the basal plasma glucose and 1-h GCT values among groups. Multivariable logistic regression analysis demonstrated that age, OGTT values >or=180 mg/dL at 1 hour and OGTT values >or=155 mg/dL at 2 hours, but not GCT values, were independent predictors for GDM (p=0.048, p=0.012 and p<0.001, respectively).


CONCLUSIONS
Results of our retrospective analysis on an unselected population are consistent with the hypothesis that GCT is not predictive of GDM and its diagnostic significance remains questionable.
Montagnana
Martina
M
Clinical Chemistry Section, Department of Morphological-Biomedical Sciences, University Hospital of Verona, Verona, Italy. martina.montagnana@med.lu.se
Lippi
Giuseppe
G
Targher
Giovanni
G
Fava
Cristiano
C
Guidi
Gian Cesare
GC
D000328:Adult; D016640:Diabetes, Gestational / Q000175:diagnosis*; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods*; D006801:Humans; D008403:Mass Screening / Q000379:methods; D011237:Predictive Value of Tests; D011247:Pregnancy; D012189:Retrospective Studies